oscillator photos on Flickr

After a recent strobist shoot it quickly became obvious that my single SB800 wasn't going to be enough, and although I was able to borrow some more from a good friend, I really needed a more permanent solution.

Not having the money to blow on 3 more SB900/800 or 600 flashes (that's posh lens money that is!) I thought I'd see what I can do with a soldering iron. Unfortunately soldering irons only emit heat and not light so I turned to ebay.

5 days later I'm the proud owner of some classic strobes. Two Vivitar 283s, a Vivitar 285 and some great little micro controllers from a friendly Dutchman.

The 283s had 300volts at their hotshoe, so they weren't going anywhere near my D300! The 285 was only 7 volts, but it's all going off camera anyway.

I have the prototype hardware sorted, now I just have to program the microcontrollers

What you can see here is

Vivitar 283 - £16 from ebay

6v 7.2Ah SLA battery - £14 from Maplin

JeeNode(V4) - €17.50

2xOptotriac isolators - £1.50 each from maplin, far cheaper from Farnell (but still cheaper than getting 300v up the Jeenode!)

The Jeenode(V4) comes complete with an RFM12B radio module, meaning I have all the parts needed to make a remote trigger. The hotshoe even unscrews from the vivitar flashes, which means I've even got a useful donor part to use for the input to the transmitter.

Button board and breadboard are for test purposes only. Triple AA battery box will only be used on the camera trigger transmitter end, not the remote strobe end. The remote end will run from the 6V SLA

Due to the low internal resistance of the 6 volt sealed lead acid battery the 283 recharges from a full blast in under 3 seconds! Probably best not to do too many of these in quick succession or the oscillator circuit is bound to melt. I'd add "improve flash cooling" to the "to-do" list.

Bar the external battery connection wires the 283 is unmodified. Everything that is required appears on the connector behind the thyristor sensor. A bit of veroboard and some 0.1" spaced circuit board pins make a good plug.

For anyone that's interested the pins are

1.......2

....3

4.......5

(This is my numbering system looking at the front of the flash from the outside).

1 - Connects to the internal triggering system, this sits at 300volts

2 - Quench1

3 - The other half of the trigger. This connects to the outside of the hotshoe. Connect this to pin 1 and the flash will fire

4 - Connection to hotshoe centre. With the Thyristor unplugged the hotshoe is disabled. Connect this to pin 1 to reenable it. I left it disconnected, I don't want 300volts on the hotshoe centre pin!

5 - Quench2

Connecting Quench1 and Quench2 together stop the flash instantly.

Connecting different resistances between it varies the power.

I'm using the connect directly together method via the microcontroller to quench the flash after a preset time. The longer the time, the higher the flash power.

Oh, and for anyone interested, this picture was taken with the SB800 on hotshoe pointed straight up, camera was tilted at 45 degrees so the flash bounced off the white ceiling and the white tiles on the wall... The white surface it's all sitting on is the top of my chest freezer in the utility room!

Progress is made, and flashes flash... www.flickr.com/photos/steve_snaps/4566541603/

Vintage Transmitter de W2GUM by Anthony Catalano

17 12

A "HOLLOW STATE" rig.

A "QRP" [low pwr] one-tube, free-running oscillator transmitter.

This method/style of building radios is called "breadboarding" because that literally was what was often used. Atlanticon Hamfest [radio exposition/flea market] Note the one-turn loop to a #47 bulb tuning aid. It also has DSP - Da Same Principle. It don't get prettier than this my fellow hams. "GUM" himself was displaying it! ...And I did not dare to ask if it was for sale for fear that he may have either justifiably slugged me or just politely smilied. You can't be sure when good stuff like this is displayed. Casio 3000EX florescent lighting.

p.s. If you like this then see:

www.flickr.com/photos/badwsky/463441817/

Toyota Land Cruiser by PleaseYesPlease

Longtime customer Herr Kringle came a knockin’ again this year with another epic custom build request. To address a new level of intercontinental delivery challenges this season, we sourced a clean J80 Land Cruiser and upgraded everything, starting with the powertrain.

Kringle Spec features a raucous 600 HP delivered to all four wheels through a twin-turbocharged 4.0L V8 coupled with a 16KW plug in hybrid dual motor setup configured to pwn even the biggest obstacles terra firma can conjure.

The package is completed by a Portable roof-mounted SatNav Unit working in tandem with our custom Compact Trans-Dimensional Oscillator, enabling Herr Kringle to deliver even the most difficult packages in little more than the space of a wink.

I hope you enjoy, and Happy Holidays!

television transmission tower by woodleywonderworks

17 2

What is the digital TV (DTV) transition?

The switch from analog to digital broadcast television is referred to as the digital TV (DTV) transition. In 1996, the U.S. Congress authorized the distribution of an additional broadcast channel to each broadcast TV station so that they could start a digital broadcast channel while simultaneously continuing their analog broadcast channel. Later, Congress has set June 12, 2009 as the final date that full-power television stations can broadcast in digital only. Your local broadcasters may make the transition before then, and some already have.

Why are we switching to DTV?

An important benefit of the switch to all-digital broadcasting is that it will free up parts of the valuable broadcast spectrum for public safety communications such as police, fire departments, and rescue squads. Also, some of the spectrum will be auctioned to companies that will be able to provide consumers with more advanced wireless services (such as wireless broadband).

Consumers also benefit because digital broadcasting allows stations to offer improved picture and sound quality, and digital is much more efficient than analog. For example, rather than being limited to providing one analog program, a broadcaster is able to offer a super sharp “high definition” (HD) digital program or multiple “standard definition” (SD) digital programs simultaneously through a process called “multicasting.” Multicasting allows broadcast stations to offer several channels of digital programming at the same time, using the same amount of spectrum required for one analog program. So, for example, while a station broadcasting in analog on channel 7 is only able to offer viewers one program, a station broadcasting in digital on channel 7 can offer viewers one digital program on channel 7-1, a second digital program on channel 7-2, a third digital program on channel 7-3, and so on. This means more programming choices for viewers. Further, DTV can provide interactive video and data services that are not possible with analog technology.

From:

www.dtv.gov/consumercorner.html

SandBox Typo - GeneTypo 01 by Spaghetti Coder

3 2

A geenrative Typography using attractors, repellers, oscillators and particles.

Stills from video: vimeo.com/spaghetticoder/genetypo001

Electronic Music instrument, 1924 by Jim Griffin

6 25

The Staccatone was invented by Hugo Gernsback and Clyde J. Fitch. Gernsback promoted it as a do-it-yourself project for amateur electronics enthusiasts. The instrument had a single vacuum tube oscillator controlled by a crude switch-based 16 note ‘keyboard’. The switch-based control gave the note a staccato tone.

-- 120 Years of Electronic Music. Net

Die Schwejk-Uhr, beautiful Pendulum Clock of restaurant Zum Schwejk in Wiesbaden Germany by Arjan Richter

7 6

A pendulum clock is a clock that uses a pendulum, a swinging weight, as its timekeeping element. The advantage of a pendulum for timekeeping is that it is a harmonic oscillator; it swings back and forth in a precise time interval dependent on its length, and resists swinging at other rates. From its invention in 1656 by Christiaan Huygens until the 1930s, the pendulum clock was the world's most precise timekeeper, accounting for its widespread use.

Throughout the 18th and 19th centuries pendulum clocks in homes, factories, offices and railroad stations served as primary time standards for scheduling daily life, work shifts, and public transportation, and their greater accuracy allowed the faster pace of life which was necessary for the Industrial Revolution.

Pendulum clocks must be stationary to operate; any motion or accelerations will affect the motion of the pendulum, causing inaccuracies, so other mechanisms must be used in portable timepieces. They are now kept mostly for their decorative and antique value. (Source: Wikipedia).

Public Clocks by Arjan Richter

..and the Mellotron unraveled by Leigh Anthony DEHANEY

17 7

today our sound class went on a field trip to cantos. a hypnotic (for me) musical museum that also included a whole wack of 'vintage' electronics..

ever wondered what was behind the sounds of 'strawberry fields'?

Nikon F501 AF + Tokina SD AF 28-70 f2.8-4.5 + MF19. Japan by C.A. Collections

Type of Camera Integral-motor autofocus 35mm single lens reflex.

Picture Format 24 x 36mm [standard 35mm (135) film format]

Lens Mount Nikon F mount

Lens More than 70 Nikkor and Series E lenses available.

Focus Modes Dual autofocus modes (Single servo and Continuous servo) focus assist and manual focusing.

Autofocus Detection System TTL phase detection system using 96 CCD's.

Autofocus Detection Range Approx. EV 4 to EV 17 using lenses f:2.8 or faster; EV 5 to EV 18 using lenses f:4.5 or faster but slower than f:2.8.

Autofocus Lock Single Servo AF - Possible once focus LED is lit and shutter release remains slightly depressed; Continuous Servo AF - focus detection continues as long as shutter release remains partially depressed.

Focus Assist Available in manual focus mode with an AF Nikkor, Nikkor or Series E lens with a maximum aperture of f:4.5 or faster

Exposure Metering Light intensity feedback measurement (for P DUAL, P HI and A), TTL full aperture centerweighted measurement (for manual exposure) employs one silicone photo diode (SPD).

Exposure Meter Switch Activated by setting film advance mode selector at S or C and lightly pressing shutter release button, remains on for approx. 8 sec. after releasing shutter release button.

Metering Range (at ISO 100 with f/1.4 lens)EV 1 to EV19

Exposure Modes Three Program (dual, normal and high speed) auto exposure modes, Auto, Aperture-Priority Auto and Manual

Programmed Auto Exposure ControlChoose from 3 modes. Camera sets both shutter speed and lens aperture automatically.

Aperture-Priority Auto Exposure ControlShutter speed automatically selected to match manually set aperture

Manual Exposure Control Both aperture and shutter speed are set manually

Shutter Electromagnetically controlled vertical-travel focal-plane shutter

Shutter Speeds Stepless from 1/2000 to 1 sec. in P DUAL, P, P HI and A auto exposure modes. Lithium niobate oscillator-controlled speeds from 1/2000 to 1 sec on manual; electromagnetically controlled Bulb setting is provided

Viewfinder Fixed eyelevel pentaprism high-eyepoint type; 0.85X magnification with 50mm lens set at infinity; approx. 92% frame coverage

Eyepiece cover Model DK-5 prevents stray light from entering eyepiece

Focusing Screen Nikon type B clear matte with central focus brackets, 12 mm circle denotes center weighted metering area; changeable with type E or J focusing screens.

Viewfinder Information Focus indicator LEDs include focus not possible warning, in-focus indication, focus-to-right and focus-to-left arrows; exposure indicator LEDs include shutter speed LEDs, over and under-exposure warning LED's; ready light comes on when Nikon dedicated flash is used.

P DUAL, P and P HI modes LED shows shutter speed selected by camera; top warning light blinks for overexposure, bottom warning LED indicates underexposure, top and bottom LEDs blink to indicate proper exposure.

A mode LED shows shutter speed automatically selected by camera, top or bottom warning LEDs blink to inducate over or under - exposure.

Manual mode Non-blinking LED shows shutter speed set on dial, blinking LED shows shutter speed for correct exposure; 2 blinking LEDs show intermediate shutter speed; no LED in B.

Auto Exposure Lock Operates in P DUAL, P, P HI, and A modes, holding button in locks exposure.

Exposure Compensation +/- 2 EV compensation (in 1/3 increments) possible with compensation dial; when film speed ring is set at DX with ISO 5000 DX coded film, exposure compensation is possible from - 1 1/3 to +2; with film speed ring set to ISO 1600, -1 to +2 is possible; at ISO 3200 only + compensation is possible; at ISO 25, -2 to +1 is possible; at ISO 12, only - compensation is possible.

Film Speed Range ISO 25 to 5000 for DX-coded film; ISO 12 to 3200 can be manually set for non-DX coded film.

Film Speed Setting At DX position, automatically set to ISO speed of DX-coded film used; manual setting possible

Film Loading Film automatically advances to first frame when shutter release button is depressed once

Film Advance In single-frame mode, film automatically advances one frame when shutter is released; in continuous shooting mode, shots are taken as long as shutter release button is depressed; shooting speed is approx. 1.7 fps to approx. 2.5 fps depending on focus mode in use.

Remote Film Rewind Use optional MC-12A.

Audible Warning Alarm With switch on, beeps; (1) when non-DX coded film is used with film speed dial set at DX;(2) when DX contacts require cleaning; (3) for under and over-exposure and possible picture blur in auto exposure modes; (4) at end of film roll; (5) during self timer operation.

Red indicator Lamp Blinks; (1) when non-DX coded film is used with film speed dial set at DX;(2) when DX contacts require cleaning; (3) for under and over-exposure and possible picture blur in auto exposure modes; (4) when shutter is released.

Frame Counter Additive type; counts back while film is being rewound

Self-timer Electronically controlled 10 sec. delay; blinking LED and beep sound indicates self-timer operation; cancellable

Reflex Mirror Automatic, instant-return type

Camera Back Hinged back with film cartridge confirmation and film advance indicator; changeable with Data Back MF-19.

Accessory Shoe Standard ISO-type hot-shoe contact; ready-light contact, TTL flash contact, monitor contact

Flash Synchronization Up to 1/125 sec. with electronic flash.

Flash Ready Light Lights up when Nikon dedicated flash is ready

Autofocus Flash Photography Possible only with Nikon SB-20.

Power Source Four 1.5V AAA batteries; with Nikon AA battery holder MB-3, four 1.5V AA batteries can be used.

Dimensions (W x H x D) Approx. 5.8 x 3.8 x 2.1 in.

Weight (without batteries) Approx. 21.3 oz.

Vintage King Oscillator DE Safety Razor With Moving Blade, Solid Brass, Made In USA, Circa 1946 by Joe Haupt

Requires a proprietary blade but a modern blade may be substituted; however, it will not oscillate like the proprietary blade.

Tesla 3-6-9 by Thomas Falla Eriksen

7 7

This is some sort of an intergalactic smart phone. Who lets us talk directly to our extra terrestrial creators. You type or speak your message into the device, and the guy on in the middle of the left part of the machine transcribe it. Then he send it to the amplifier, which is located in the bottom of the middle part of the machine. The amplifier sends the boosted signal up to the transmitter. The big wheel like thing in the center of the whole machine. The transmitter is based on Edward Leedskalnin's electro magnetic flywheel.

Ed is showing of his book "A book in every home" right above the transmitter.

The incomng signal comes in through the receiver, located the middle of the right part of the machine. It is in fact a miniature version of the Schaffer Vega diversity system made by Ken Schaffer, originally meant for electric guitars (used by guitarists like Angus Young, Tony Iommi, David Gilmour, Ace Frehley, Eddie Van Halen to name a few). It is aided by 16 Tesla coils mounted in a circle around the reciever.

Nikola Tesla himself is tweaking the knobs, making sure everything is in perfect sync.

The Tesla coils also provide the whole machine with power.

They collect excess electrisity from the air. We waste tons of electrisity out in the aether every second. The power is routed through a step up/down transformer mounted above the receiver and Tesla coils.

The Tesla coils usually pick up more electrisity than the unit needs, so much of it gets stored in the PMH magnet storage behind Edward Leedskalnin. If you don't know who Nikola Tesla and Edward Leedkalninare, you have some reading to do. Loose both yourself and your lead in the many stories of these long gone heroes.

The signal from outer space is fed through a crystal skull who serves as a step down transformer. The message must be simplified and deciphered. Or else we wouldnt be able to understand anything. Then the signal is routed straight to the guy you gave your first message to (if the signal is weak, it will go through the amplifier).

He transcribes the messages in to written words. If you for some reason is unable to read, the message will go through a speak synthesis. The spoken words will either be sent through the speaker (bottom left), or through the minijack output (top left). The translators instruments look suspiciously like the old EMS VCS-3 synthesizers. And one of the good old Moogs. The whole machine should fit in the palm of your hand. Depending on the size of your hand of course.

The whole drawing is inspired by a quote by Nikola Tesla. "If only the world knew the significance of 3-6-9". Or something like that. I do not remember exactly how he said it. But he believed that the numbers 3, 6 and 9 was the key to the universe. And I wouldn't be surprised if he was right. After all, he truly was an extraordinary gentleman.

This makes up the basic composition. In a quite crude way, as it is linked to simple graphic elements. 3 main parts, and 6 big wires (that connects the 3 main parts). And 3 + 6 is 9. There we have it. Not quite what Tesla had in mind, but more than enough to keep me busy for a few weeks.

The music and instruments of AC/DC and Jean Michel Jarre also had quite an influence on how this drawing turned out. Particularly Angus Young's old wireless unit. When the right and middle part of the drawing was constructed, I suddenly started banging my head into the wall and kept doing that for a while. Until my girlfriend gave me a ticket to a concert with Jarre as a birthday present. My head suddenly banged through the aforementioned wall. Seeing and hearing the old analog synthesizers made some ideas appear that finished the machine.

This is the drawing that I am most satisfied with to this date. It looks better in real life that on this grainy little .jpeg with reflections from both sunlight and a slightly psychedelic wallpaper (the drawing is sitting in a frame in this picture).

Sorry about the photographic quality. I will upload a better picture sometime later.

If anybody wants to know, the dimensions are: 90x204cm.

If you are interested in drawings without squids, feel free to visit my other page.

www.flickr.com/photos/when-i-am-not-drawing-squids/

Geoff Downes 1987 (Buggles) by Neil Vance

11 14

THE MAN! Mr GD!, One half of the Buggles, showing of one or two casiotones!.. no really, that is a beautifull collection. He is a big fan of American Synthesizers for the warmth of their oscillators. He is not a fan of Japanese Synths, especially the Yamaha 'FM' DX7 / TX816.

Shortwavemusic (GMA Remodel) by Gianni Motti Assistant

William Basinski

⚫️

Book :

Modulations

Une Histoire De La Musique Électronique

Peter Shapiro & Caipirinha Productions

Éditions Allia

2007

CD :

Frank Bretschneider & Peter Duimelinks

Fflux

Brombron

BROMBRON10

Design . Lenno Verhoog

iMusic :

Ryoji Ikeda

Variations For Modulated Sinewaves

Raster - Noton

RN20TO2000

GMAhz ...

Vintage Ameco Code Practice Oscillator, Model CPS, An Aerotron Product, 2 Vacuum Tubes (50C5 & 35W4), Made In USA, Circa 1960s by Joe Haupt

4 1

Auction Item 142A -- Cledis Estes Auctions II of Medina, Ohio.

The Sweet 32 Speaker Interrupter-Switcher Installation Thing (Ceci n'est pas la haute-fidélité) by James Schidlowsky

9 7

Phase 2: After a couple of years amassing a collection of speakers taken from stuff found in the trash, and countless hours of work, I finally got them off my floor and onto the wall.

There are 47 speakers per panel, but only 16 per panel are wired up to the control box. The box takes a 2 channel input and randomly selects which of the speakers the sound is directed to (for each panel). The rate can be controlled by the knob, or via an external CV. There is also the optional interruption control on a per-channel basis... this cuts the sound going to a panel according to the rate set via the knob (or external CV). Alas, the box and the speakers are not very clean-sounding, so not just any audio is suitable. It is best to feed it with simple drone oscillators.

No video could really demonstrate what this installation sounds like in person, with the sound moving around.

I created a page about this project here: www.jamesschidlowsky.ca/sweet32.html .

751.001 Výstaviště Brno, 07/07/17 by Richard Jones

The "Oslvanany Oscillator" operated by Grumpy Railtours, included street running on the section of line from Brno Dolní to Výstaviště Brno (Brno Exhibition Centre). 751.001 is seen at the terminus, 07/07/17

Moog Modular 55 by grobie

Needs your free vote of support at: goo.gl/heBmZ7

With enough votes, it could be made into an actual set by LEGO!

Also, please check out my Minimoog models at: goo.gl/iucWKS

AND

the Prism & Spectrum at: goo.gl/pFTr3v

Nikon F-501 by Raúl Sá Dantas

7 3

Nikon F-501/N2020

Integral-motor autofocus 35mm single lens reflex.

Picture Format 24 x 36mm DX coded 35mm (135) film format

Dual autofocus modes (Single servo and Continuous servo) focus assist and manual focusing.

Autofocus Lock Single Servo AF

Focus Assist Available in manual focus mode with an AF Nikkor, Nikkor or Series E lens with a maximum aperture of f:4.5 or faster

Exposure Metering Light intensity feedback measurement (for P DUAL, P HI and A), TTL full aperture centerweighted measurement (for manual exposure) employs one silicone photo diode (SPD).

Metering Range (at ISO 100 with f/1.4 lens) EV 1 to EV19

Exposure Modes Three Programs (dual, normal and high speed) auto exposure modes, Auto, Aperture-Priority Auto and Manual

Shutter Electromagnetically controlled vertical-travel focal-plane shutter

Electromagnetic shutter Release.

Viewfinder Fixed eyelevel pentaprism high-eyepoint type; 0.85X magnification with 50mm lens set at infinity; approx. 92% frame coverage

Focusing Screen Nikon type B clear matte with central focus brackets, 12 mm circle denotes centre weighted metering area; changeable with type E or J focusing screens.

Film Speed Range ISO 25 to 5000 for DX-coded film; ISO 12 to 3200 can be manually set for non-DX coded film.

Motorised film advance, with automatic film loading and rewind

Frame Counter Additive type; counts back while film is being rewound

Self-timer Electronically controlled 10 sec. delay.

Reflex Mirror Automatic, instant-return type

Data Back MF-19.

Flash Synchronization Up to 1/125 sec.

Power source: Nikon AA battery holder MB-3, f4 1.5V AA batteries

Dimensions (W x H x D) 15 x 10 x 5 cm.

Weight (without batteries) Approx. 600g

I invite you to visit my camera site at Classic Cameras in english.

Convido-os a visitar o minha página Câmaras & Cia. em português

Lockheed C-141 Model in TDT by NASA on The Commons

Lockheed C-141 model in the Transonic Dynamics Tunnel (TDT). By the late 1940s, with the advent of relatively thin, flexible aircraft wings, the need was recognized for testing dynamically and elastically scaled models of aircraft. In 1954, NASA's predecessor agency, the National Advisory Committee on Aeronautics (NACA), began converting the Langley 19-foot Pressure Tunnel for dynamic testing of aircraft structures. The old circular test section was reduced to 16 x 16 feet, and slotted walls were added for transonic operation. The TDT was provided with special oscillator vanes upstream of the test section to create controlled gusty air to simulate aircraft response to gusts. A model support system was devised that freed the model to pitch and plunge as the wings started oscillating in response to the fluctuating airstream. The TDT was completed in 1959. It was the world's first aeroelastic testing tunnel.

NASA Media Usage Guidelines

Credit: NASA

Image Number: L-1962-08937

Date: November 16, 1962

Moog Modular 55 by grobie

Needs your free vote of support at: goo.gl/heBmZ7

With enough votes, it could be made into an actual set by LEGO!

Also, please check out my Minimoog models at: goo.gl/iucWKS

AND

the Prism & Spectrum at: goo.gl/pFTr3v

Proximity Sensor by Phillip Hughes

"Magic Wire" is so called because of detecting proximity to antenna.

THE MAGIC WIRE

As shown in the diagram, the input tube is a type 6R7 duo-diode triode. The triode section forms the oscillator, in conjunction with the coil L1 which is center-tapped to the cathode. When the triode section is oscillating, the r.f. voltage developed from cathode to ground is impressed on the diode section, causing current to flow through R2 and making the diode plates negative with respect to ground. The control grid of the 25L6 power tube is connected to the diode plates of the 6R7 and consequently a negative bias is placed on the grid which reduces its plate current to a very low value. As soon as the triode ceases to oscillate, there is no longer any r.f. voltage applied to the diodes, the voltage drops and the 25L6 draws high plate current, causing the relay to operate.

It will be noted that no rectifier tube or filler circuit is required in this design, yet the instrument functions on either a.c. or d.c. On a.c., the 6R7 oscillations and the 25L6 draws plate current only on the positive half-cycles. This principle effects a considerable saving in construction cost and in the size of the instrument.

After the parts required have been obtained, the first step in building the unit is to make the chassis, which consists simply of a piece of 16-gauge aluminum or steel bent and drilled in accordance with the plan shown. The front panel, which is included with the standard 6 by 6 cabinet, is drilled and a hole and grommet are placed in the rear panel. The oscillator coil is made by winding 100 turns of No.28 d.c.c. wire on a one-inch bakelite tube 3-1/4 inches long. A tap is brought out at the center of the winding. When the winding has been completed, the entire coil is dipped in a hot half-and-half mixture of beeswax and paraffin to keep the winding in place and exclude moisture. The sensitivity of the outfit is largely dependent upon the efficiency of the coil, so it should be carefully made. C1 is mounted on a small piece of 1/8-inch bakelite, because it must be insulated from the panel.

Wire the chassis first, starting with the heater circuits. Do not connect in the power cord until all wiring has been completed. The shield of the 25L6 is connected to its cathode, the shield of the 6E7 to the heater terminal which goes directly to the line. When all the main wiring has been completed, bring the power cord through the rear panel hole, and solder the three terminals to the terminal strip. The antenna wire is brought in through a rubber-grommeted hole in the top of the cabinet and connected to the stator or plate terminal of C1. A knot in the wire will relieve any strain on this connection. Stranded wire is preferred for the antenna.

The capacitances of C1 and C2 are largely dependent upon the length of antenna wire desired. If only 4 or 5 feet are required, C2 may be omitted. On the other hand, if the wire exceeds 15 feet, C2 will have to be larger than the value given. If the capacitance of C1 were made large (say 150 mmf. or more), C2 could of course be omitted but then the adjustment would become too critical.

The relay employed is a 3,000-ohm plug-in type of standard manufacture. It is a double-pole model and will handle a non-inductive load of 100 watts. It is somewhat more sensitive than is required and any other good relay of 1,000 ohms or more resistance should be suitable. The capacitor, C4, is shunted across the relay coil to prevent chattering. It may be advisable, in some cases, to put a 0.1 mf. paper capacitor across the relay contacts to stop sparking on heavy loads. It is better practice, however, to use a separate power relay when operating any but light loads.

In operation, the antenna wire is strung out well away from grounded metal objects and a 110-volt lamp is plugged into the outlet on the panel. When the tubes have heated, the lamp should light when the antenna wire is touched. If it lights without touching the wire, C2 should be screwed down until the lamp goes out. These adjustments should be made with C1 about one-half mashed. The panel may then screwed in on the cabinet and final adjustment made. This is done by gradually adjusting the vernier knob of the dial until the light remains lit when adjusting but goes out when the hand is removed from the dial. This may be carried to a point where the light will flash as soon as one approaches within 3 feet of the wire or instrument. It is better not to aim for such sensitivity, though, since it will vary somewhat with line voltage. A good, practical and stable point is about six to fifteen minutes or so for the instrument to acquire a stable point of operation owing to its sensitivity.

PARTS REQUIRED

C1 - Midget variable capacitor, 60 mmf. (see text)

C2 - Trimmer capacitor, 35 mmf. or more (see text)

C3 - Tubular paper capacitor, 0.05 mf. or more, 200 v.

C4 - Electrolytic capacitor, 10 mf., 100 V.

R1 - Carbon resistor, 5 meg, 1 watt

R2 - Carbon resistor, 1 meg., 1 watt

R4 - Wire-wound resistor, 5,000 ohms, 10 watts

R5 - Wire-wound resistor, 10,000 ohms, 10 watts

1 -- Steel cabinet 6x6x6 inches, front & back panels removable

1 -- Piece 16-gauge aluminum, for chassis 5-1/2 x 7-3/4 inches

1 -- Piece bakelite tubing, 1 inch diameter., 3-1/2 inches long

1 -- Piece bakelite, 1'1/2 x 1-1/2, 1/8 inch thick for C1

2 -- Octal wafer sockets, 1-1/2 inches center for mounting holes

1 -- 5-prong wafer socket, 1-1/2 inches center for mounting holes

1 -- Relay, Utah type RAC-110, 3,000 ohm

1 -- 6R7 metal tube

1 -- 25L6 metal tube

1 -- Kurz-Kasch vernier dial, small

1 -- Resistor line cord, 280 ohms (R3)

1 -- Single outlet receptacle

Miscellaneous screws, nuts, mounting bracket, and grommets.

- James P Hughes

Highland Light Station- North Truro MA (3) by Kevin Stewart

nrhp # 87001463- The Highland Light (previously known as Cape Cod Light) is an active lighthouse on the Cape Cod National Seashore in North Truro, Massachusetts. The current tower was erected in 1857, replacing two earlier towers that had been built in 1797 and 1831. It is the oldest and tallest lighthouse on Cape Cod.[5]

The grounds are open year-round, while the light is open to the public from May until late October, with guided tours available. Highland Light is owned by the National Park Service, and was cared for by the Highland Museum and Lighthouse, Inc. until 2014 when Eastern National, another non-profit group, took over the contract to operate the facility as a tourist attraction.[6] The United States Coast Guard operates the light as an aid to navigation.[7] The United States Navy ship USS Highland Light (IX-48) was named after the light. It is listed on the National Register of Historic Places as Highland Light Station.

In 1797, a station authorized by George Washington was established at this point on the Cape, with a wood lighthouse to warn ships about the dangerous coastline between Cape Ann and Nantucket. It was the first light on Cape Cod. In 1833, the wood structure was replaced by a brick tower and in 1840 a new lantern and lighting apparatus was installed. In 1857 the lighthouse was declared dangerous and demolished, and for a total cost of $17,000, the current 66-foot brick tower was constructed.[8]

On June 6, 1900, the light was changed from a fixed beam to flashing, with a new. The new Barbier, Benard & Turenne first-order Fresnel lens had four panels of 0.92 meter focal distance, revolved in mercury, and gave, every five seconds, flashes of about 192,000 candlepower nearly one-half second in duration. While the new lens was being installed, the light from a third-order lens was exhibited atop a temporary tower erected near the lighthouse; it was later sold at auction. The Highland Light was then the most powerful on the east coast of the United States. Two four-horsepower oil engines with compressors operated by an engine fueled by kerosene, were added to ensure that the fog signal could be activated within ten minutes instead of the previous 45. A new fog signal was installed in 1929, an electrically operated air oscillator, to make it audible over a greater distance.[6]

The lighthouse was converted to electric operation in 1932 with a 1000-watt beacon. In 1946, Highland Light's Fresnel lens was replaced by modern aerobeacons, first by a Crouse-Hinds DCB-36 double rotating light and then by a Carlisle & Finch DCB-224, with a second unit as backup. Unfortunately, the Fresnel lens was severely damaged when it was removed, but fragments are on display in the museum on site. The light was fully automated by 1986 with a Crouse-Hinds DCB-224 rotating beacon.[9][6] In 1998, a VRB-25 optical system was installed.[3][6] Most recently, the light source is a Vega Marine LED beacon model 44/2.5 installed in April 2017.[10]

The current location of the lighthouse is not the original site. It was in danger of falling down the cliff due to beach erosion, so the structure was moved 450 feet (140 m) to the west. The government funding to do so was supplemented by money raised through fund raising by the Truro Historical Society.[11] The move was accomplished by International Chimney Corp. of Buffalo, New York and Expert House Movers of Maryland over a period of 18 days in July, 1996.[3][6] The move left the light station on Cape Cod National Seashore property, bordering the Highland Golf Course. After an errant golf ball broke a window, they were replaced with unbreakable material. In 1998, the keeper's house was modified to be a gift shop and museum. The lighthouse grounds are open year-round on Highland Light Road in Truro, with tours and the museum available from a National Park Service partner, Eastern National,[12] during the summer months.

from Wikipedia

Elegant retreat. by Matteo Cammelli

"Studiava l'esatto punto in cui l'onda, dopo essersi rotta una decina di metri più indietro, si allungava divenuta lago, e specchio e macchia d'olio risalendo la delicata china della spiaggia e finalmente si arrestava l'estremo bordo orlato da un delicato perlage per esitare un attimo e alfine, sconfitta, tentare una elegante ritirata lasciandosi scivolare indietro, lungo la via di un ritorno apparentemente facile ma, in realtà, preda destinata alla spugnosa avidità di quella sabbia che, fin lì imbelle, improvvisamente si svegliava e, la breve corsa dell'acqua in rotta, nel nulla svaporava. Bartleboom guardava. Nel cerchio imperfetto del suo universo ottico la perfezione di quel moto oscillatorio formulava promesse che l'irripetibile unicità di ogni singola onda condannava a non esser mantenute. Non c'era verso di fermare quel continuo avvicendarsi di creazione e distruzione.

Shot with Nikon D600 + Tamron 28-75 f2.8. Processed with VSCOcam app.

Nikon F4S + Nikkor 50mm f1.8 D + MB21 + DA20 Viewfinder + MF23. Japan. by C.A. Collections

6 3

Type of camera:

Integral-motor autofocus 35mm single lens reflex.

Picture format:

24mm x 36mm standard 35mm film format.

Lens mount:

Nikon bayonet type.

Lenses:

Lenses with Nikon F mount with some limitations.

Focus modes:

Autofocus and manual with electronic rangefinder.

Autofocus modes:

Single servo AF with focus priority and continous servo AF with release priority.

AF detection system:

TTL phase detection system - Nikon Advanced AM200 module.

AF detection range:

EV minus 1 to EV 18 at ISO 100.

AF lock:

Possible in single servo AF mode once a stationary subject is in focus as long as the shutter button is depressed; in continuous servo AF, focus can be locked with AF-L button.

Electronic rangefinder:

Available in manual focus mode with an AF Nikkor and other AI-type Nikkor lenses with a maximum aperture of f/5.6 or faster.

Exposure metering:

Matrix metering, centre-weighted metering (60/40) and spot metering.

Metering range:

EV 0 to 21 for matrix and (at 100 ISO centre-weighted; EV 2 to 21 for spot with f/1.4 metering. lens):

Exposure meter:

Activated by lightly pressing the shutter release button; stays on for approx 16 sec after finger leaves button.

Exposure modes:

Programmed auto-multi, shutter-priority auto, aperture priority auto and manual.

Multiple exposure controll:

Via lever

Exposure compensation:

Use exposure compensation dial within +/- 2 EV range in 1/3 EV steps.

Auto expsosure lock:

By sliding the AE-L lever while the meter is on.

Shutter:

Electromagnetically controlled vertical-travel focal-plane shutter.

Shutter release:

By motor trigger.

Shutter speeds:

Lithium niobate oscillator-controlled speeds from 1/8000 sec to 30 sec; stepless in programmed auto and aperture-priority auto exposure modes; 1 EV steps in shutter priority auto and manual exposure modes; long exposure at B or T setting.

Viewfinder:

Interchangeable high-eyepoint; 0.70x magnification with 50mm lens at infinity; 100% frame coverage.

Eyepoint:

22mm approx.

Eyepiece shutter:

Built in.

Focusing screen:

Interchangeable Nikon advanced B-type screen BriteView screen.

Viewfinder information:

Focus indications, frame counter, exposure mode, metering system, shutter speed, aperture, exposure compensation, electronic analogue display, exposure compensation mark and flash-ready are all shown in LCD readout.

Film speed range:

ISO 25 to 5000 for DX-coded film; ISO 6 to 6400 in 1/3 steps for manual setting.

Film speed setting:

At DX position, automatically set to speed of DX-coded film; manual setting available.

Film loading:

Film automatically advances to first frame when shutter release button is depressed once.

Film advance:

In single-frame shooting mode, film automatically advances one frame when shutter is released; in continuous high, continuous low and continuous silent shooting modes, shots are taken as long as shutter release button is depressed; high speed 5.7 fps; low 3.4 fps, silent 1.0 fps.

Film rewind:

Manuel or automatic. Manuel by turning crank; rewind stops automatically when film is rewound.

Frame counter:

Additive type; showing in the viewfinder and on the camera.

Self-timer:

Electronically controlled; approx 10 seconds; blinking LED indicates self-timer operation; cancellable.

Depth-of-fiel preview button:

Provides visual verification of depth-of-field in aperture-priority auto or manual exposure modes.

Reflex mirror:

Automatic, instant-return type with lockup facillity.

Camera back:

Hinged; interchangeable with Nikon Multi-Control Back MF-23, World Time Data Back MF-22 or 250 exposure magazine back MF-24.

Accessory shoe:

Standard ISO-type hotshoe contact; ready light contact, TTL flash contact, monitor contact.

Flash sync control:

Normal sync, normal with red-eye, slow sync and rear curtain sync provided.

Flash synchronisation:

In programmed auto or aperture-priority auto, shutter operates from 1/250 to 1/60 sec in normal sync or 1/250 to 30 sec in slow sync; in shutter-priority auto or manual exposure mode, shutter fires at speed set, and when set from 1/250 to 1/8000 sec, shutter is automatically set to 1/250 sec.

TTL multi sensor:

Five segment multi sensor used for TTL auto flash control.

Automatic balanced fill-flash:

Possible when AF Nikkor or AI-P Nikkor lens is used with Nikon dedicated Speedlights.

Flash recommended/ ready light:

Lights up in green when flash is recommended and no speedlight is attached; when speedlight is attached, lights up in red when Nikon dedicated speedlight is ready to fire, or blinks to warn of insufficient light for a correct exposure.

Power source:

Nikon High speed battery pack MB-21 six alkaline or NiCd of AA-type; Battery pack MB-20 four alkaline of AA-type; Batteryy pack MB-23 six alkaline of AA-type or MN-20.

Battery check:

Sufficient if LCD is visible in the viewfinder then lightly pressing shutter relese button, and remains on for approx 18 sec after finger is removed from the button.

Dimensions (W x H x D):

169 x 157 x 77mm (MB-23), 169 x 139 x 77mm (MB-21), 196 x 118 x 77mm (MB-20).

Weight (body only):

1400g (MB-23), 1280g (MB-21), 1090g (MB-20).

Lens Compatibility

With AF-Nikkor lenses or some other lenses in combination with the TC-16 or TC-16A autofocus teleconverter, the F4 provides full autofocus operation. Full manual focusing, or manual focusing with the F4's electronic rangefinder, is used with virtually all Nikon F-mount Nikkor and Nikon lenses. Use the following table as a guide.

JFET oscillator with a buffer that is not terrible by synx508

2 1

Most buffer circuits for JFET oscillators seem to throw out the advantages, introduce noise and distortion. This one is good to about 150MHz by scaling the 68 pF capacitors. You’ll get a hefty output power. Note that the distortion cancellation from the diode is supply voltage/amplitude sensitive so adust supply for lowest 2f

714.028 Výstaviště Brno , 07/07/17 by Richard Jones

The "Oslvanany Oscillator" operated by Grumpy Railtours, included street running on the section of line from Brno Dolní to Výstaviště Brno (Brno Exhibition Centre). 714.028 is seen at the terminus, 07/07/17

Oscillons From The Anti Sun by Gianni Motti Assistant

Stereolab

☀️

Art :

Peter Saville

Pulsar CP1919

Reworked

Arkitip N°0049

CD :

Cavern Of Anti Matter

Blood Drums

Duophonic

DUHF35

Music by Joe Dilworth . Tim Gane . Holger Zapf

Design by Vanina Schmitt

iTunes :

Lustmord

Dark Matter

Touch

TO:102

GMAnti Matter ...

Skanti TRP-8250 HF Transceiver by Randy Perkins

8 7

Here is my Skanti TRP-8250 HF 250 watt all mode transceiver. As you can see in the photo, it is now setup on 7213 KHz lower sideband. The box on the right is where I can plug in my microphone, CW key, and headphones. It will put out 250 watts on USB, LSB, CW, AM, digital modes. On any frequency from 1.5 to 29.9 MHz. The photo is just the control unit. The main transceiver unit is inside a lower cabinet. It consists of 4 major components. The Control unit, Transceiver unit, Power Supply and the Automatic Antenna Tuner.

These Skanti radios were built back in the 1980's from Skanti Radio Denmark intended for ship maritime radio communications.

Moog Modular 55 by grobie

Needs your free vote of support at: goo.gl/heBmZ7

With enough votes, it could be made into an actual set by LEGO!

Also, please check out my Minimoog models at: goo.gl/iucWKS

AND

the Prism & Spectrum at: goo.gl/pFTr3v

M6A7 Heavy Tank (Turning Point) by Justsuper9

7 3

Armed with a Sonic Oscillator Heat Ray capable of melting steel out to 500 yards, the M6A7 is part of a long secret

Pentagon energy weapons research program dating back to the late 1930s. Built out of inspiration from the Operation

Chitown group. Here's the sound it makes when it fires btw: www.flickr.com/photos/js9productions/5975439246/

751.001 Výstaviště Brno, 07/07/17 by Richard Jones

DIY: "vso" - a Very Small Oscillator (lm311) by linux-works

6 3

building a very tiny oscillator for a DIY L/C/F meter:

www.amb.org/forum/air-wiring-a-tiny-module-pics-t1480.html

this is the oscillator part of the project. the arduino part will follow (using LCDuino v1.0 from AMB.org and linuxworks labs)

Nikon N70 by kingkong21

10 13

1994

Type of camera Integral-motor autofocus 35mm single-lens reflex (SLR) with built-in TTL flash

Picture format 24mm x 36mm (standard 35mm film format); Panorama (F70D only): 13mm x 36mm, changeable by Panorama switch

Lens mount Nikon F mount

Lenses Nikkor and Nikon lenses having Nikon F mount with some limitations; see chart below

Viewfinder Fixed eyelevel pentaprism high-eyepoint type; 0.78x magnification with 50mm lens set at infinity; approx. 92% frame coverage

Eyepoint Approx. 18mm

Viewfinder illuminator: Automatically activates when exposure meter is on

Autofocus area Wide and Spot selectable

Focus modes: Autofocus, and Manual with Electronic Rangefinder

Autofocus modes: Single Servo AF and Continuous Servo AF

Autofocus detection system: Nikon CAM274 autofocus module

Autofocus detection range: Approx. EV -1 to 19 (at ISO 100)

Autofocus lock: Possible once stationary subject is in focus in Single Servo AF

Electronic rangefinder Available in Manual focus mode with AF Nikkor and other AI-type Nikkor lens with a maximum aperture of f/5.6 or faster

Focusing Screen New Nikon advanced B-type BriteView screen II; fixed

Focus tracking: Automatically activated with a moving subject

Exposure Modes Programmed Auto (Auto-Multi Program and Vari-Program), Shutter-Priority Auto, Aperture-Priority Auto and Manual

Programmed Auto exposure control: Camera sets both shutter speed and lens aperture automatically; Flexible Program possible in increments of 1/3 EV. Vari-Program: Eight kinds built-in: Portrait Program, Hyperfocal Program, Landscape Program, Close-Up Program, Sport Program, Silhouette Program, Night Scene Program, and Motion Effect

Program; each has its own program line

Shutter-Priority Auto exposure control: Aperture automatically selected to match manually set shutter speed

Aperture-Priority Auto exposure control: Shutter speed automatically selected to match manually set aperture

Manual exposure control: Both aperture and shutter speed are set manually

Shutter speed/aperture adjustment: Rotating the Command Dial changes shutter speed in and modes or aperture value in mode in 1/2 EV steps. To change aperture value in mode, rotate the Command Dial while pressing the aperture button

Quick Recall function By QR button the original or favourite camera settings can be recalled; up to three settings can be memorised

Auto exposure lock: Available by pressing the AE-L button while the exposure meter is on

Viewfinder information LCD: Focus area, focus indications, exposure metering system, exposure mode, Flexible Program, shutter speed, aperture, electronic analogue display, exposure compensation and flash output compensation are all shown in LCD readout; also shows flash recommended light and ready light LEDs

LCD panel information: Shutter speed, aperture, QR, focus area, film speed setting mode, film advance mode, focus mode, exposure mode, exposure metering system, flash sync mode, exposure compensation/flash output level compensation, All-Mode Exposure Bracketing/Flash Exposure Bracketing and frame counter/compensation value, film loading, film rewind, self-timer and battery power

Metering range (at ISO 100 with f/1.4 lens) EV -I to EV 20 for Matrix and Centre-Weighted metering; EV 4 to EV 20 for Spot metering

Exposure Metering Switch Activated by lighdy pressing shutter release button; stays on for 8 sec., after finger leaves button

Exposure control Modes Three built-in exposure meters - Matrix, Centre-Weighted and Spot

Exposure compensation With exposure compensation button; +-5 EV range, in 1/3 EV steps

AE Lock By pressing AE-L (auto exposure lock) button while exposure meter is activated

Film speed range ISO 25 to 5000 for DX-coded film; ISO 6 to 6400 can be manually set

Shutter Electromagnetically controlled vertical-travel focal-plane shutter

Shutter speeds Lithium niobate oscillator-controlled speeds from 1/4000 to 30 sec in 1/3 EV steps; electro-magnetically controlled Bulb setting is provided

Shutter Release: By motor trigger

Automatic film advance automatically advances to first frame when shutter release button is depressed once. In single-frame and single-frame silent rewind mode, film automatically advances one frame when, shutter is released; in continuous high or continuous low shooting mode, shots are taken as long as shutter release button is depressed; in continuous high mode, shooting speed is approx. 3.7 fps, and in continuous low approx. 2.0 fps

Frame counter Additive type; counts back while film is being rewound

Film rewind By pressing IN and Ps button; fast rewind or silent rewind is selectable

Self timer Electronically controlled; blinking LED indicates self-timer operation; cancellable

Dioptre adjustment: -1.5 to +1.0 dioptre

Reflex mirror Automatic, instant-return type

Camera back Hinged back with film cartridge confirmation window; unchangeable

Accessory shoe Standard ISO-type with hot-shoe contact, ready-light contact, TTL flash contact, monitor contact; mount receptacle for Posi-Mount system provided

Built-in TTL flash: Guide number: 14 (ISO 100, m); flash coverage: 28mm or longer lens; Red-Eye Reduction, TTL flash control including 3D Multi-Sensor Balanced Fill-Flash, Slow Sync and Rear-Cuttain Sync are possible

Flash synchronization Up to 1/125 sec. TTL Multi Sensor Five-segment multi sensor used for TTL auto flash control; Automaffc Balanced FiD-Flash with TTL Multi-Sensor Possible when AF Nikkor or AI-P Nikkor lens is used with built-in Speedlight or Nikon Speedlight SB26, SB-23, SB-22, SB-20, etc.

Monitor Pre-flash Built-in TTL Speedlight or Nikon Speedlight SB-26 fires Monitor Pre-flash(es) for TTL multi sensor when AF Nikkor or AI-P Nikkor lens is used

Flash recommended light Lights up when flash is recommended

Flash ready-light When Speedlight is off: blinks when using flash is recommended; when Speedlight is on: lights up when built-in Speedlight or Nikon dedicated Speedlight is ready to fire; blinks after shooting to warn of insufficient light for correct exposure

Batteries Two CR123A-type lithium batteries

Battery power confirmation: for sufficient power; indicates batteries are nearing exhaustion; blinking indicates batteries are just about exhausted; no indication/symbol appears when batteries are completely exhausted or improperly installed

Body finish: Silver and Black available

Dimensions (W x H x D): 151 x 103 x 70mm (F70), 151 x 103 x 71mm (F70D)

Weight (body only) 585g (F70), 600g (F70D)

KRC2 by Anthony Westbrook

Rear view of the oscillator board as it arrives. No construction is reqiured here. All connections to the regenerative board are made to the tags at the top left hand side of the oscillator board.

Nikola Tesla Museum: Old Photos by Esa Ruoho

Experiment to illustrate the capacity of the oscillator for creating a great electrical movement.

Bulova Accutron 1970 by Szabolcs Toth

10 8

Ő itt egy több mint 30 éves Accutron óra, elektromos, hangvillás szerkezet. A kép illusztrációnak készült egy cikkhez az Óra Magazinban.

"Max Hetzel találta fel a hangvillával működő órát. A hangvilla rezgésszáma szigorúan meghatározott és állandó. Az Accutron órában egy 20 mm hosszú hangvilla másodperenként 360 rezgést végez, amit egy hozzácsatlakozó kilincsmű visz a fogaskerék rendszerre és a mutatókra. Pontossága és egyszerűsége miatt verhetetlennek tartották. Az első amerikai mesterséges holdak vezérlőkészülékét Accutron óra szabályozta. Karrierjének a kvarcóra vetett véget." forrás: wikipedia

This here, is a 30 years old Accutron wrist watch, driven with an electromagnetically oscillated tuning fork.

"Bulova's Accutron watches, first sold in October 1960, use a 360 hertz tuning fork to drive a mechanical gear train to turn the hands. The inventor, Max Hetzel, was born in Basel, Switzerland, and joined the Bulova Watch Company of Bienne, Switzerland, in 1948. The tuning fork was powered by a one-transistor electronic oscillator circuit, so the Accutron qualifies as the first electronic watch" from wikipedia

Strobist info:
580EXII in Lastolite Ezybox from near above,
LP120 geled green as background from below and behind table,
the watch was suspended above a silver fill card,
and a very-very snooted 580EXII pointed to the face of the watch.
Triggered by Elinchrom Skyports.

okuboswarm by neil banas

11 3

A stochastically forced, damped oscillator model of zooplankton swarming. But is it art? coast.ocean.washington.edu/~neil/okuboswarming/

Cat - Domestic Cat - House Cat (Felis Catus) by HISTOGRAPHY by DM & DBM.

The cat (Felis catus), commonly referred to as the domestic cat or house cat, is the only domesticated species in the family Felidae. Recent advances in archaeology and genetics have shown that the domestication of the cat occurred in the Near East around 7500 BC. It is commonly kept as a house pet and farm cat, but also ranges freely as a feral cat avoiding human contact. It is valued by humans for companionship and its ability to kill vermin. Because of its retractable claws it is adapted to killing small prey like mice and rats. It has a strong flexible body, quick reflexes, sharp teeth, and its night vision and sense of smell are well developed. It is a social species, but a solitary hunter and a crepuscular predator. Cat communication includes vocalizations like meowing, purring, trilling, hissing, growling, and grunting as well as cat body language. It can hear sounds too faint or too high in frequency for human ears, such as those made by small mammals. It also secretes and perceives pheromones.

Female domestic cats can have kittens from spring to late autumn in temperate zones and throughout the year in equatorial regions, with litter sizes often ranging from two to five kittens. Domestic cats are bred and shown at events as registered pedigreed cats, a hobby known as cat fancy. Animal population control of cats may be achieved by spaying and neutering, but their proliferation and the abandonment of pets has resulted in large numbers of feral cats worldwide, contributing to the extinction of bird, mammal and reptile species.

As of 2017, the domestic cat was the second most popular pet in the United States, with 95.6 million cats owned and around 42 million households owning at least one cat. In the United Kingdom, 26% of adults have a cat, with an estimated population of 10.9 million pet cats as of 2020. As of 2021, there were an estimated 220 million owned and 480 million stray cats in the world.

Etymology and naming

The origin of the English word cat, Old English catt, is thought to be the Late Latin word cattus, which was first used at the beginning of the 6th century. The Late Latin word may be derived from an unidentified African language. The Nubian word kaddîska 'wildcat' and Nobiin kadīs are possible sources or cognates. The Nubian word may be a loan from Arabic قَطّ‎ qaṭṭ ~ قِطّ qiṭṭ.

The forms might also have derived from an ancient Germanic word that was imported into Latin and then into Greek, Syriac, and Arabic. The word may be derived from Germanic and Northern European languages, and ultimately be borrowed from Uralic, cf. Northern Sámi gáđfi, 'female stoat', and Hungarian hölgy, 'lady, female stoat'; from Proto-Uralic *käďwä, 'female (of a furred animal)'.

The English puss, extended as pussy and pussycat, is attested from the 16th century and may have been introduced from Dutch poes or from Low German puuskatte, related to Swedish kattepus, or Norwegian pus, pusekatt. Similar forms exist in Lithuanian puižė and Irish puisín or puiscín. The etymology of this word is unknown, but it may have arisen from a sound used to attract a cat.

A male cat is called a tom or tomcat (or a gib, if neutered). A female is called a queen or a molly, if spayed, especially in a cat-breeding context. A juvenile cat is referred to as a kitten. In Early Modern English, the word kitten was interchangeable with the now-obsolete word catling.

A group of cats can be referred to as a clowder or a glaring.

Taxonomy

The scientific name Felis catus was proposed by Carl Linnaeus in 1758 for a domestic cat. Felis catus domesticus was proposed by Johann Christian Polycarp Erxleben in 1777. Felis daemon proposed by Konstantin Satunin in 1904 was a black cat from the Transcaucasus, later identified as a domestic cat.

In 2003, the International Commission on Zoological Nomenclature ruled that the domestic cat is a distinct species, namely Felis catus. In 2007, it was considered a subspecies, F. silvestris catus, of the European wildcat (F. silvestris) following results of phylogenetic research. In 2017, the IUCN Cat Classification Taskforce followed the recommendation of the ICZN in regarding the domestic cat as a distinct species, Felis catus.

Evolution

Main article: Cat evolution

The domestic cat is a member of the Felidae, a family that had a common ancestor about 10 to 15 million years ago. The evolutionary radiation of the Felidae began in Asia during the Miocene around 8.38 to 14.45 million years ago. Analysis of mitochondrial DNA of all Felidae species indicates a radiation at 6.46 to 16.76 million years ago. The genus Felis genetically diverged from other Felidae around 6 to 7 million years ago. Results of phylogenetic research shows that the wild members of this genus evolved through sympatric or parapatric speciation, whereas the domestic cat evolved through artificial selection. The domestic cat and its closest wild ancestor are diploid and both possess 38 chromosomes and roughly 20,000 genes.

Domestication

See also: Domestication of the cat and Cats in ancient Egypt

It was long thought that the domestication of the cat began in ancient Egypt, where cats were venerated from around 3100 BC, However, the earliest known indication for the taming of an African wildcat was excavated close by a human Neolithic grave in Shillourokambos, southern Cyprus, dating to about 7500–7200 BC. Since there is no evidence of native mammalian fauna on Cyprus, the inhabitants of this Neolithic village most likely brought the cat and other wild mammals to the island from the Middle Eastern mainland. Scientists therefore assume that African wildcats were attracted to early human settlements in the Fertile Crescent by rodents, in particular the house mouse (Mus musculus), and were tamed by Neolithic farmers. This mutual relationship between early farmers and tamed cats lasted thousands of years. As agricultural practices spread, so did tame and domesticated cats. Wildcats of Egypt contributed to the maternal gene pool of the domestic cat at a later time.

The earliest known evidence for the occurrence of the domestic cat in Greece dates to around 1200 BC. Greek, Phoenician, Carthaginian and Etruscan traders introduced domestic cats to southern Europe. During the Roman Empire they were introduced to Corsica and Sardinia before the beginning of the 1st millennium. By the 5th century BC, they were familiar animals around settlements in Magna Graecia and Etruria. By the end of the Western Roman Empire in the 5th century, the Egyptian domestic cat lineage had arrived in a Baltic Sea port in northern Germany.

The leopard cat (Prionailurus bengalensis) was tamed independently in China around 5500 BC. This line of partially domesticated cats leaves no trace in the domestic cat populations of today.

During domestication, cats have undergone only minor changes in anatomy and behavior, and they are still capable of surviving in the wild. Several natural behaviors and characteristics of wildcats may have pre-adapted them for domestication as pets. These traits include their small size, social nature, obvious body language, love of play, and high intelligence. Captive Leopardus cats may also display affectionate behavior toward humans but were not domesticated. House cats often mate with feral cats. Hybridisation between domestic and other Felinae species is also possible, producing hybrids such as the Kellas cat in Scotland.

Development of cat breeds started in the mid 19th century. An analysis of the domestic cat genome revealed that the ancestral wildcat genome was significantly altered in the process of domestication, as specific mutations were selected to develop cat breeds. Most breeds are founded on random-bred domestic cats. Genetic diversity of these breeds varies between regions, and is lowest in purebred populations, which show more than 20 deleterious genetic disorders.

Characteristics

Main article: Cat anatomy

Size

The domestic cat has a smaller skull and shorter bones than the European wildcat. It averages about 46 cm (18 in) in head-to-body length and 23–25 cm (9.1–9.8 in) in height, with about 30 cm (12 in) long tails. Males are larger than females. Adult domestic cats typically weigh 4–5 kg (8.8–11.0 lb).

Skeleton

Cats have seven cervical vertebrae (as do most mammals); 13 thoracic vertebrae (humans have 12); seven lumbar vertebrae (humans have five); three sacral vertebrae (as do most mammals, but humans have five); and a variable number of caudal vertebrae in the tail (humans have only three to five vestigial caudal vertebrae, fused into an internal coccyx). The extra lumbar and thoracic vertebrae account for the cat's spinal mobility and flexibility. Attached to the spine are 13 ribs, the shoulder, and the pelvis. Unlike human arms, cat forelimbs are attached to the shoulder by free-floating clavicle bones which allow them to pass their body through any space into which they can fit their head.

Skull

The cat skull is unusual among mammals in having very large eye sockets and a powerful specialized jaw. Within the jaw, cats have teeth adapted for killing prey and tearing meat. When it overpowers its prey, a cat delivers a lethal neck bite with its two long canine teeth, inserting them between two of the prey's vertebrae and severing its spinal cord, causing irreversible paralysis and death. Compared to other felines, domestic cats have narrowly spaced canine teeth relative to the size of their jaw, which is an adaptation to their preferred prey of small rodents, which have small vertebrae.

The premolar and first molar together compose the carnassial pair on each side of the mouth, which efficiently shears meat into small pieces, like a pair of scissors. These are vital in feeding, since cats' small molars cannot chew food effectively, and cats are largely incapable of mastication.: Cats tend to have better teeth than most humans, with decay generally less likely because of a thicker protective layer of enamel, a less damaging saliva, less retention of food particles between teeth, and a diet mostly devoid of sugar. Nonetheless, they are subject to occasional tooth loss and infection.

Claws

Cats have protractible and retractable claws. In their normal, relaxed position, the claws are sheathed with the skin and fur around the paw's toe pads. This keeps the claws sharp by preventing wear from contact with the ground and allows for the silent stalking of prey. The claws on the forefeet are typically sharper than those on the hindfeet. Cats can voluntarily extend their claws on one or more paws. They may extend their claws in hunting or self-defense, climbing, kneading, or for extra traction on soft surfaces. Cats shed the outside layer of their claw sheaths when scratching rough surfaces.

Most cats have five claws on their front paws and four on their rear paws. The dewclaw is proximal to the other claws. More proximally is a protrusion which appears to be a sixth "finger". This special feature of the front paws on the inside of the wrists has no function in normal walking but is thought to be an antiskidding device used while jumping. Some cat breeds are prone to having extra digits ("polydactyly"). Polydactylous cats occur along North America's northeast coast and in Great Britain.

Ambulation

The cat is digitigrade. It walks on the toes, with the bones of the feet making up the lower part of the visible leg. Unlike most mammals, it uses a "pacing" gait and moves both legs on one side of the body before the legs on the other side. It registers directly by placing each hind paw close to the track of the corresponding fore paw, minimizing noise and visible tracks. This also provides sure footing for hind paws when navigating rough terrain. As it speeds up from walking to trotting, its gait changes to a "diagonal" gait: The diagonally opposite hind and fore legs move simultaneously.

Balance

Cats are generally fond of sitting in high places or perching. A higher place may serve as a concealed site from which to hunt; domestic cats strike prey by pouncing from a perch such as a tree branch. Another possible explanation is that height gives the cat a better observation point, allowing it to survey its territory. A cat falling from heights of up to 3 m (9.8 ft) can right itself and land on its paws.

During a fall from a high place, a cat reflexively twists its body and rights itself to land on its feet using its acute sense of balance and flexibility. This reflex is known as the cat righting reflex. A cat always rights itself in the same way during a fall, if it has enough time to do so, which is the case in falls of 90 cm (3.0 ft) or more. How cats are able to right themselves when falling has been investigated as the "falling cat problem".

Coats

Main article: Cat coat genetics

The cat family (Felidae) can pass down many colors and patterns to their offspring. The domestic cat genes MC1R and ASIP allow for the variety of color in coats. The feline ASIP gene consists of three coding exons. Three novel microsatellite markers linked to ASIP were isolated from a domestic cat BAC clone containing this gene and were used to perform linkage analysis in a pedigree of 89 domestic cats that segregated for melanism.[citation needed]

Senses

Main article: Cat senses

Vision

A cat's nictitating membrane shown as it blinks

Cats have excellent night vision and can see at only one-sixth the light level required for human vision. This is partly the result of cat eyes having a tapetum lucidum, which reflects any light that passes through the retina back into the eye, thereby increasing the eye's sensitivity to dim light. Large pupils are an adaptation to dim light. The domestic cat has slit pupils, which allow it to focus bright light without chromatic aberration. At low light, a cat's pupils expand to cover most of the exposed surface of its eyes. The domestic cat has rather poor color vision and only two types of cone cells, optimized for sensitivity to blue and yellowish green; its ability to distinguish between red and green is limited. A response to middle wavelengths from a system other than the rod cells might be due to a third type of cone. This appears to be an adaptation to low light levels rather than representing true trichromatic vision. Cats also have a nictitating membrane, allowing them to blink without hindering their vision.

Hearing

The domestic cat's hearing is most acute in the range of 500 Hz to 32 kHz. It can detect an extremely broad range of frequencies ranging from 55 Hz to 79 kHz, whereas humans can only detect frequencies between 20 Hz and 20 kHz. It can hear a range of 10.5 octaves, while humans and dogs can hear ranges of about 9 octaves. Its hearing sensitivity is enhanced by its large movable outer ears, the pinnae, which amplify sounds and help detect the location of a noise. It can detect ultrasound, which enables it to detect ultrasonic calls made by rodent prey. Recent research has shown that cats have socio-spatial cognitive abilities to create mental maps of owners' locations based on hearing owners' voices.

Smell

Cats have an acute sense of smell, due in part to their well-developed olfactory bulb and a large surface of olfactory mucosa, about 5.8 cm2 (0.90 in2) in area, which is about twice that of humans. Cats and many other animals have a Jacobson's organ in their mouths that is used in the behavioral process of flehmening. It allows them to sense certain aromas in a way that humans cannot. Cats are sensitive to pheromones such as 3-mercapto-3-methylbutan-1-ol, which they use to communicate through urine spraying and marking with scent glands. Many cats also respond strongly to plants that contain nepetalactone, especially catnip, as they can detect that substance at less than one part per billion. About 70–80% of cats are affected by nepetalactone. This response is also produced by other plants, such as silver vine (Actinidia polygama) and the herb valerian; it may be caused by the smell of these plants mimicking a pheromone and stimulating cats' social or sexual behaviors.

Taste

Cats have relatively few taste buds compared to humans (470 or so versus more than 9,000 on the human tongue). Domestic and wild cats share a taste receptor gene mutation that keeps their sweet taste buds from binding to sugary molecules, leaving them with no ability to taste sweetness. They, however, possess taste bud receptors specialized for acids, amino acids like protein, and bitter tastes. Their taste buds possess the receptors needed to detect umami. However, these receptors contain molecular changes that make the cat taste of umami different from that of humans. In humans, they detect the amino acids of glutamic acid and aspartic acid, but in cats they instead detect nucleotides, in this case inosine monophosphate and l-Histidine. These nucleotides are particularly enriched in tuna. This has been argued is why cats find tuna so palatable: as put by researchers into cat taste, "the specific combination of the high IMP and free l-Histidine contents of tuna" .. "produces a strong umami taste synergy that is highly preferred by cats". One of the researchers involved in this research has further claimed, "I think umami is as important for cats as sweet is for humans".[87]

Cats also have a distinct temperature preference for their food, preferring food with a temperature around 38 °C (100 °F) which is similar to that of a fresh kill; some cats reject cold food (which would signal to the cat that the "prey" item is long dead and therefore possibly toxic or decomposing).

Whiskers

To aid with navigation and sensation, cats have dozens of movable whiskers (vibrissae) over their body, especially their faces. These provide information on the width of gaps and on the location of objects in the dark, both by touching objects directly and by sensing air currents; they also trigger protective blink reflexes to protect the eyes from damage.: 47

Behavior

See also: Kitten

The cat secretes and perceives pheromones. Female cats, called queens, are polyestrous with several estrus cycles during a year, lasting usually 21 days. They are usually ready to mate between early February and August in northern temperate zones and throughout the year in equatorial regions.

Several males, called tomcats, are attracted to a female in heat. They fight over her, and the victor wins the right to mate. At first, the female rejects the male, but eventually, the female allows the male to mate. The female utters a loud yowl as the male pulls out of her because a male cat's penis has a band of about 120–150 backward-pointing penile spines, which are about 1 mm (0.039 in) long; upon withdrawal of the penis, the spines may provide the female with increased sexual stimulation, which acts to induce ovulation.

After mating, the female cleans her vulva thoroughly. If a male attempts to mate with her at this point, the female attacks him. After about 20 to 30 minutes, once the female is finished grooming, the cycle will repeat. Because ovulation is not always triggered by a single mating, females may not be impregnated by the first male with which they mate. Furthermore, cats are superfecund; that is, a female may mate with more than one male when she is in heat, with the result that different kittens in a litter may have different fathers.

The morula forms 124 hours after conception. At 148 hours, early blastocysts form. At 10–12 days, implantation occurs. The gestation of queens lasts between 64 and 67 days, with an average of 65 days.

Data on the reproductive capacity of more than 2,300 free-ranging queens were collected during a study between May 1998 and October 2000. They had one to six kittens per litter, with an average of three kittens. They produced a mean of 1.4 litters per year, but a maximum of three litters in a year. Of 169 kittens, 127 died before they were six months old due to a trauma caused in most cases by dog attacks and road accidents. The first litter is usually smaller than subsequent litters. Kittens are weaned between six and seven weeks of age. Queens normally reach sexual maturity at 5–10 months, and males at 5–7 months. This varies depending on breed. Kittens reach puberty at the age of 9–10 months.

Cats are ready to go to new homes at about 12 weeks of age, when they are ready to leave their mother. They can be surgically sterilized (spayed or castrated) as early as seven weeks to limit unwanted reproduction. This surgery also prevents undesirable sex-related behavior, such as aggression, territory marking (spraying urine) in males and yowling (calling) in females. Traditionally, this surgery was performed at around six to nine months of age, but it is increasingly being performed before puberty, at about three to six months. In the United States, about 80% of household cats are neutered.

Lifespan and health

Main articles: Cat health and Aging in cats

The average lifespan of pet cats has risen in recent decades. In the early 1980s, it was about seven years,: 33 rising to 9.4 years in 1995: 33 and an average of about 13 years as of 2014 and 2023. Some cats have been reported as surviving into their 30s, with the oldest known cat dying at a verified age of 38.

Neutering increases life expectancy: one study found castrated male cats live twice as long as intact males, while spayed female cats live 62% longer than intact females.: 35 Having a cat neutered confers health benefits, because castrated males cannot develop testicular cancer, spayed females cannot develop uterine or ovarian cancer, and both have a reduced risk of mammary cancer.

Disease

Main article: List of feline diseases

About 250 heritable genetic disorders have been identified in cats, many similar to human inborn errors of metabolism. The high level of similarity among the metabolism of mammals allows many of these feline diseases to be diagnosed using genetic tests that were originally developed for use in humans, as well as the use of cats as animal models in the study of the human diseases. Diseases affecting domestic cats include acute infections, parasitic infestations, injuries, and chronic diseases such as kidney disease, thyroid disease, and arthritis. Vaccinations are available for many infectious diseases, as are treatments to eliminate parasites such as worms, ticks, and fleas.

Ecology

Habitats

The domestic cat is a cosmopolitan species and occurs across much of the world. It is adaptable and now present on all continents except Antarctica, and on 118 of the 131 main groups of islands, even on the isolated Kerguelen Islands. Due to its ability to thrive in almost any terrestrial habitat, it is among the world's most invasive species. It lives on small islands with no human inhabitants. Feral cats can live in forests, grasslands, tundra, coastal areas, agricultural land, scrublands, urban areas, and wetlands.

The unwantedness that leads to the domestic cat being treated as an invasive species is twofold. On one hand, as it is little altered from the wildcat, it can readily interbreed with the wildcat. This hybridization poses a danger to the genetic distinctiveness of some wildcat populations, particularly in Scotland and Hungary, possibly also the Iberian Peninsula, and where protected natural areas are close to human-dominated landscapes, such as Kruger National Park in South Africa. However, its introduction to places where no native felines are present also contributes to the decline of native species.

Ferality

Main article: Feral cat

Feral cats are domestic cats that were born in or have reverted to a wild state. They are unfamiliar with and wary of humans and roam freely in urban and rural areas. The numbers of feral cats is not known, but estimates of the United States feral population range from 25 to 60 million. Feral cats may live alone, but most are found in large colonies, which occupy a specific territory and are usually associated with a source of food. Famous feral cat colonies are found in Rome around the Colosseum and Forum Romanum, with cats at some of these sites being fed and given medical attention by volunteers.

Public attitudes toward feral cats vary widely, from seeing them as free-ranging pets to regarding them as vermin.

Some feral cats can be successfully socialized and 're-tamed' for adoption; young cats, especially kittens and cats that have had prior experience and contact with humans are the most receptive to these efforts.

Impact on wildlife

Main article: Cat predation on wildlife

On islands, birds can contribute as much as 60% of a cat's diet. In nearly all cases, the cat cannot be identified as the sole cause for reducing the numbers of island birds, and in some instances, eradication of cats has caused a "mesopredator release" effect; where the suppression of top carnivores creates an abundance of smaller predators that cause a severe decline in their shared prey. Domestic cats are a contributing factor to the decline of many species, a factor that has ultimately led, in some cases, to extinction. The South Island piopio, Chatham rail, and the New Zealand merganser are a few from a long list, with the most extreme case being the flightless Lyall's wren, which was driven to extinction only a few years after its discovery. One feral cat in New Zealand killed 102 New Zealand lesser short-tailed bats in seven days. In the US, feral and free-ranging domestic cats kill an estimated 6.3 – 22.3 billion mammals annually.

In Australia, the impact of cats on mammal populations is even greater than the impact of habitat loss. More than one million reptiles are killed by feral cats each day, representing 258 species. Cats have contributed to the extinction of the Navassa curly-tailed lizard and Chioninia coctei.

Interaction with humans

Main article: Human interaction with cats

Cats are common pets throughout the world, and their worldwide population as of 2007 exceeded 500 million. As of 2017, the domestic cat was the second most popular pet in the United States, with 95.6 million cats owned and around 42 million households owning at least one cat. In the United Kingdom, 26% of adults have a cat, with an estimated population of 10.9 million pet cats as of 2020. As of 2021, there were an estimated 220 million owned and 480 million stray cats in the world.

Cats have been used for millennia to control rodents, notably around grain stores and aboard ships, and both uses extend to the present day.

As well as being kept as pets, cats are also used in the international fur trade and leather industries for making coats, hats, blankets, stuffed toys, shoes, gloves, and musical instruments. About 24 cats are needed to make a cat-fur coat. This use has been outlawed in the United States since 2000 and in the European Union (as well as the United Kingdom) since 2007.

Cat pelts have been used for superstitious purposes as part of the practice of witchcraft, and are still made into blankets in Switzerland as traditional medicine thought to cure rheumatism.

A few attempts to build a cat census have been made over the years, both through associations or national and international organizations (such as that of the Canadian Federation of Humane Societies) and over the Internet, but such a task does not seem simple to achieve. General estimates for the global population of domestic cats range widely from anywhere between 200 million to 600 million. Walter Chandoha made his career photographing cats after his 1949 images of Loco, an especially charming stray taken in, were published around the world. He is reported to have photographed 90,000 cats during his career and maintained an archive of 225,000 images that he drew from for publications during his lifetime.

Shows

Main article: Cat show

A cat show is a judged event in which the owners of cats compete to win titles in various cat-registering organizations by entering their cats to be judged after a breed standard. It is often required that a cat must be healthy and vaccinated in order to participate in a cat show. Both pedigreed and non-purebred companion ("moggy") cats are admissible, although the rules differ depending on the organization. Competing cats are compared to the applicable breed standard, and assessed for temperament.

Infection

Main article: Feline zoonosis

Cats can be infected or infested with viruses, bacteria, fungus, protozoans, arthropods or worms that can transmit diseases to humans. In some cases, the cat exhibits no symptoms of the disease. The same disease can then become evident in a human. The likelihood that a person will become diseased depends on the age and immune status of the person. Humans who have cats living in their home or in close association are more likely to become infected. Others might also acquire infections from cat feces and parasites exiting the cat's body. Some of the infections of most concern include salmonella, cat-scratch disease and toxoplasmosis.

History and mythology

Main articles: Cultural depictions of cats and Cats in ancient Egypt

In ancient Egypt, cats were worshipped, and the goddess Bastet often depicted in cat form, sometimes taking on the war-like aspect of a lioness. The Greek historian Herodotus reported that killing a cat was forbidden, and when a household cat died, the entire family mourned and shaved their eyebrows. Families took their dead cats to the sacred city of Bubastis, where they were embalmed and buried in sacred repositories. Herodotus expressed astonishment at the domestic cats in Egypt, because he had only ever seen wildcats.

Ancient Greeks and Romans kept weasels as pets, which were seen as the ideal rodent-killers. The earliest unmistakable evidence of the Greeks having domestic cats comes from two coins from Magna Graecia dating to the mid-fifth century BC showing Iokastos and Phalanthos, the legendary founders of Rhegion and Taras respectively, playing with their pet cats. The usual ancient Greek word for 'cat' was ailouros, meaning 'thing with the waving tail'. Cats are rarely mentioned in ancient Greek literature. Aristotle remarked in his History of Animals that "female cats are naturally lecherous." The Greeks later syncretized their own goddess Artemis with the Egyptian goddess Bastet, adopting Bastet's associations with cats and ascribing them to Artemis. In Ovid's Metamorphoses, when the deities flee to Egypt and take animal forms, the goddess Diana turns into a cat.

Cats eventually displaced weasels as the pest control of choice because they were more pleasant to have around the house and were more enthusiastic hunters of mice. During the Middle Ages, many of Artemis's associations with cats were grafted onto the Virgin Mary. Cats are often shown in icons of Annunciation and of the Holy Family and, according to Italian folklore, on the same night that Mary gave birth to Jesus, a cat in Bethlehem gave birth to a kitten. Domestic cats were spread throughout much of the rest of the world during the Age of Discovery, as ships' cats were carried on sailing ships to control shipboard rodents and as good-luck charms.

Several ancient religions believed cats are exalted souls, companions or guides for humans, that are all-knowing but mute so they cannot influence decisions made by humans. In Japan, the maneki neko cat is a symbol of good fortune. In Norse mythology, Freyja, the goddess of love, beauty, and fertility, is depicted as riding a chariot drawn by cats. In Jewish legend, the first cat was living in the house of the first man Adam as a pet that got rid of mice. The cat was once partnering with the first dog before the latter broke an oath they had made which resulted in enmity between the descendants of these two animals. It is also written that neither cats nor foxes are represented in the water, while every other animal has an incarnation species in the water. Although no species are sacred in Islam, cats are revered by Muslims. Some Western writers have stated Muhammad had a favorite cat, Muezza. He is reported to have loved cats so much, "he would do without his cloak rather than disturb one that was sleeping on it". The story has no origin in early Muslim writers, and seems to confuse a story of a later Sufi saint, Ahmed ar-Rifa'i, centuries after Muhammad. One of the companions of Muhammad was known as Abu Hurayrah ("father of the kitten"), in reference to his documented affection to cats.

Superstitions and rituals

Many cultures have negative superstitions about cats. An example would be the belief that encountering a black cat ("crossing one's path") leads to bad luck, or that cats are witches' familiars used to augment a witch's powers and skills. The killing of cats in Medieval Ypres, Belgium, is commemorated in the innocuous present-day Kattenstoet (cat parade). In mid-16th century France, cats would be burnt alive as a form of entertainment, particularly during midsummer festivals. According to Norman Davies, the assembled people "shrieked with laughter as the animals, howling with pain, were singed, roasted, and finally carbonized". The remaining ashes were sometimes taken back home by the people for good luck.

According to a myth in many cultures, cats have multiple lives. In many countries, they are believed to have nine lives, but in Italy, Germany, Greece, Brazil and some Spanish-speaking regions, they are said to have seven lives, while in Arabic traditions, the number of lives is six. An early mention of the myth can be found in John Heywood's The Proverbs of John Heywood (1546)

Husband, (quoth she), ye studie, be merrie now,

And even as ye thinke now, so come to yow.

Nay not so, (quoth he), for my thought to tell right,

I thinke how you lay groning, wife, all last night.

Husband, a groning horse and a groning wife

Never faile their master, (quoth she), for my life.

No wife, a woman hath nine lives like a cat.

The myth is attributed to the natural suppleness and swiftness cats exhibit to escape life-threatening situations. Also lending credence to this myth is the fact that falling cats often land on their feet, using an instinctive righting reflex to twist their bodies around. Nonetheless, cats can still be injured or killed by a high fall.

Advertising For The King Oscillator Safety Razor In The Minneapolis Star Tribune Newspaper, June 16, 1946 by Joe Haupt

SALA DE MAQUINAS @ VISUAL BRASIL by Rodrigo Carvalho

8 1

“Sala de Máquinas” (Engine Room) is an audiovisual interactive installation, which intends to reflect on the idea of the reutilization of what we have acknowledged as obsolete...in this case old modified TVs that react to sound!

An electronic oscillator is connected to an open circuit, in a way that when the user touches 2 metal bars he/she himself/herself becomes the electrical resistance therefore being able to vary the frequency of sound.

The old modified TVs react to this sound as an oscilloscope having all kinds of different patterns and reactions.

FESTIVAL VISUAL BRASIL // BARCELONA 2010

Daphne Polyzos, Jordi Planas, Miguel Neto, Rodrigo Carvalho

fotos by Silvio Teixeira

Too watch the video click here :: www.vimeo.com/15019498

Matching Circuit Tattoos 2 by Andrew_Squirrel

7 4

Met this dude (Aaron) at a Mennonite party and immediately noticed his tattoo which is a "ring oscillator" (see: www.iue.tuwien.ac.at/phd/stockinger/img262.gif. Had to get a photo with him because he is the first person I've met with a circuit tattoo similar to mine! He is currently in grad school up in Vancouver studying FPGA optimization.

(Photo credit: Dusty & his iphone)

Moog Modular 55 by grobie

Will be live for voting on the Lego Ideas site by next week.

Until that time, please cast a free vote of support for the Minimoog models at: goo.gl/iucWKS

the Prism & Spectrum at: goo.gl/pFTr3v

Church Interior, Paris, France. by HISTOGRAPHY by DM & DBM.

In music, the organ is a keyboard instrument of one or more pipe divisions or other means for producing tones. The organs have usually two or three, up to five, manuals for playing with the hands and a pedalboard for playing with the feet. With the use of registers, several groups of pipes can be connected to one manual.

Overview

Pipe organs, which use air moving through pipes to produce sounds. The air is supplied by bellows, an electric motor or water (water organ). Since the 16th century, pipe organs have used various materials for pipes, which can vary widely in timbre and volume. Increasingly hybrid organs are appearing in which pipes are augmented with electric additions;

Non-piped organs, which include:

pump organs, also known as reed organs or harmoniums, which like the accordion and mouth organs (both Eastern and Western), notably the harmonica, use air to excite free reeds;

electronic organs (both analog and digital), notably the Hammond organ, which generate electronically produced sound through one or more loudspeakers;

Mechanical organs, which include the barrel organ and Orchestrion. These are controlled by mechanical means such as pinned barrels or book music. Little barrel organs dispense with the hands of an organist and bigger organs are powered in most cases by an organ grinder or today by other means such as an electric motor.

History

Predecessors to the organ include:

Panpipes, pan flute, syrinx, and nai, etc., are considered as ancestor of the pipe organ.

Aulos, an ancient double reed instrument with two pipes, is the origin of the word Hydr-aulis (water-aerophone).

Origins

Depiction of an organ in the Utrecht Psalter

The organ is a relatively old musical instrument, dating from the time of Ctesibius of Alexandria (285–222 BC), who invented the water organ. It was played throughout the Ancient Greek and Ancient Roman world, particularly during races and games. During the early medieval period it spread from the Byzantine Empire, where it continued to be used in secular (non-religious) and imperial court music, to Western Europe, where it gradually assumed a prominent place in the liturgy of the Catholic Church. Subsequently, it re-emerged as a secular and recital instrument in the Classical music tradition.

Early organs

3rd century BC: the Hydraulis, ancient Greek water-powered organ played by valves.

1st century (at least): the Ptera and the Pteron, an ancient Roman organ similar in appearance to the portative organs

2nd century: the Magrepha, ancient Hebrew organ of ten pipes played by a keyboard

8th century: Pippin's organ of 757 (Carolingian dynasty) was sent as a gift to the West by the Byzantine emperor Constantine V

9th century: the automatic flute player (and possibly automatic hydropowered organ), a mechanical organ by the Banū Mūsā brothers[citation needed]

Medieval organs

Medieval organs include:

Portative organ: a small portable medieval instrument

Positive organ: a somewhat larger though still portable instrument

Regal: a portable late-medieval instrument with reed pipes and bellows; forerunner of the harmonium and reed organ

Pipe organs

The pipe organ is the largest musical instrument. These instruments vary greatly in size, ranging from a cubic meter to a height reaching five floors, and are built in churches, synagogues, concert halls, and homes. Small organs are called "positive" (easily placed in different locations) or "portative" (small enough to carry while playing).

The pipes are divided into ranks and controlled by the use of hand stops and combination pistons. Although the keyboard is not expressive as on a piano and does not affect dynamics (it is binary; pressing a key only turns the sound on or off), some divisions may be enclosed in a swell box, allowing the dynamics to be controlled by shutters. Some organs are totally enclosed, meaning that all the divisions can be controlled by one set of shutters. Some special registers with free reed pipes are expressive.

It has existed in its current form since the 14th century, though similar designs were common in the Eastern Mediterranean from the early Byzantine period (from the 4th century AD) and precursors, such as the hydraulic organ, have been found dating to the late Hellenistic period (1st century BC). Along with the clock, it was considered one of the most complex human-made mechanical creations before the Industrial Revolution. Pipe organs range in size from a single short keyboard to huge instruments with over 10,000 pipes. A large modern organ typically has three or four keyboards (manuals) with five octaves (61 notes) each, and a two-and-a-half octave (32-note) pedal board.

Wolfgang Amadeus Mozart called the organ the "King of instruments". Some of the biggest instruments have 64-foot pipes (a foot here means "sonic-foot", a measure quite close to the English measurement unit)[citation needed] and it sounds to an 8 Hz frequency fundamental tone. Perhaps the most distinctive feature is the ability to range from the slightest sound to the most powerful, plein-jeu impressive sonic discharge, which can be sustained in time indefinitely by the organist. For instance, the Wanamaker organ, located in Philadelphia, US, has sonic resources comparable with three simultaneous symphony orchestras. Another interesting feature lies in its intrinsic "polyphony" approach: each set of pipes can be played simultaneously with others, and the sounds mixed and interspersed in the environment, not in the instrument itself.

Church

Most organs in Europe, the Americas, and Australasia can be found in Christian churches.

The introduction of church organs is traditionally attributed to Pope Vitalian in the 7th century. Due to its simultaneous ability to provide a musical foundation below the vocal register, support in the vocal register, and increased brightness above the vocal register, the organ is ideally suited to accompany human voices, whether a congregation, a choir, or a cantor or soloist.

Most services also include solo organ repertoire for independent performance rather than by way of accompaniment, often as a prelude at the beginning the service and a postlude at the conclusion of the service.

Today this organ may be a pipe organ (see above), a digital or electronic organ that generates the sound with digital signal processing (DSP) chips, or a combination of pipes and electronics. It may be called a church organ or classical organ to differentiate it from the theatre organ, which is a different style of instrument. However, as classical organ repertoire was developed for the pipe organ and in turn influenced its development, the line between a church and a concert organ became harder to draw.

Concert hall

In the late 19th century and early 20th century, symphonic organs flourished in secular venues in the United States and the United Kingdom, designed to replace symphony orchestras by playing transcriptions of orchestral pieces. Symphonic and orchestral organs largely fell out of favor as the orgelbewegung (organ reform movement) took hold in the middle of the 20th century, and organ builders began to look to historical models for inspiration in constructing new instruments. Today, modern builders construct organs in a variety of styles for both secular and sacred applications.

Theatre and cinema

The theatre organ or cinema organ was designed to accompany silent movies. Like a symphonic organ, it is made to replace an orchestra. However, it includes many more gadgets, such as mechanical percussion accessories and other imitative sounds useful in creating movie sound accompaniments such as auto horns, doorbells, and bird whistles. It typically features the Tibia pipe family as its foundation stops and the regular use of a tremulant possessing a depth greater than that on a classical organ.

Theatre organs tend not to take nearly as much space as standard organs, relying on extension (sometimes called unification) and higher wind pressures to produce a greater variety of tone and larger volume of sound from fewer pipes. Unification gives a smaller instrument the capability of a much larger one, and works well for monophonic styles of playing (chordal, or chords with solo voice). The sound is, however, thicker and more homogeneous than a classically designed organ.

In the US the American Theater Organ Society (ATOS) has been instrumental in programs to preserve examples of such instruments.

Chamber organ

A chamber organ is a small pipe organ, often with only one manual, and sometimes without separate pedal pipes that is placed in a small room, that this diminutive organ can fill with sound. It is often confined to chamber organ repertoire, as often the organs have too few voice capabilities to rival the grand pipe organs in the performance of the classics. The sound and touch are unique to the instrument, sounding nothing like a large organ with few stops drawn out, but rather much more intimate. They are usually tracker instruments, although the modern builders are often building electropneumatic chamber organs.

Pre-Beethoven keyboard music may usually be as easily played on a chamber organ as on a piano or harpsichord, and a chamber organ is sometimes preferable to a harpsichord for continuo playing as it is more suitable for producing a sustained tone.

Non-piped organs

Reed or pump organ

The pump organ, reed organ or harmonium, was the other main type of organ before the development of the electronic organ. It generated its sounds using reeds similar to those of an accordion. Smaller, cheaper and more portable than the corresponding pipe instrument, these were widely used in smaller churches and in private homes, but their volume and tonal range was extremely limited. They were generally limited to one or two manuals; they seldom had a pedalboard.

Harmonium or parlor organ: a reed instrument, usually with several stops and two foot-operated bellows.

American reed organ: similar to the Harmonium, but that works on negative pressure, sucking air through the reeds.

Melodeon: a reed instrument with an air reservoir and a foot-operated bellows. It was popular in the US in the mid-19th century. (This is not to be confused with the diatonic button accordion which is also known as the melodeon.)

The chord organ was invented by Laurens Hammond in 1950. It provided chord buttons for the left hand, similar to an accordion. Other reed organ manufacturers have also produced chord organs, most notably Magnus from 1958 to the late 1970s.

Electronic organs

Since the 1930s, pipeless electric instruments have been available to produce similar sounds and perform similar roles to pipe organs. Many of these have been bought both by houses of worship and other potential pipe organ customers, and also by many musicians both professional and amateur for whom a pipe organ would not be a possibility. Far smaller and cheaper to buy than a corresponding pipe instrument, and in many cases portable, they have taken organ music into private homes and into dance bands and other new environments, and have almost completely replaced the reed organ.

Hammond

The Hammond organ was the first successful electric organ, released in the 1930s. It used mechanical, rotating tonewheels to produce the sound waveforms. Its system of drawbars allowed for setting volumes for specific sounds, and it provided vibrato-like effects. The drawbars allow the player to choose volume levels. By emphasizing certain harmonics from the overtone series, desired sounds (such as 'brass' or 'string') can be imitated. Generally, the older Hammond drawbar organs had only preamplifiers and were connected to an external, amplified speaker. The Leslie speaker, which rotates to create a distinctive tremolo, became the most popular.

Though originally produced to replace organs in the church, the Hammond organ, especially the model B-3, became popular in jazz, particularly soul jazz, and in gospel music. Since these were the roots of rock and roll, the Hammond organ became a part of the rock and roll sound. It was widely used in rock and popular music during the 1960s and 1970s by bands like Emerson, Lake and Palmer, Procol Harum, Santana and Deep Purple. Its popularity resurged in pop music around 2000, in part due to the availability of clonewheel organs that were light enough for one person to carry.

Allen

In contrast to Hammond's electro-mechanical design, Allen Organ Company introduced the first totally electronic organ in 1938, based on the stable oscillator designed and patented by the company's founder, Jerome Markowitz. Allen continued to advance analog tone generation through the 1960s with additional patents. In 1971, in collaboration with North American Rockwell, Allen introduced the world's first commercially available digital musical instrument. The first Allen Digital Organ is now in the Smithsonian Institution.

Other analogue electronic

Frequency divider organs used oscillators instead of mechanical parts to make sound. These were even cheaper and more portable than the Hammond. They featured an ability to bend pitches.

From the 1940s up until the 1970s, small organs were sold that simplified traditional organ stops. These instruments can be considered the predecessor to modern portable keyboards, as they included one-touch chords, rhythm and accompaniment devices, and other electronically assisted gadgets. Lowrey was the leading manufacturer of this type of organs in the smaller (spinet) instruments.

In the 1960s and 1970s, a type of simple, portable electronic organ called the combo organ was popular, especially with pop, Ska (in the late 1970s and early 1980s) and rock bands, and was a signature sound in the rock music of the period, such as The Doors and Iron Butterfly. The most popular combo organs were manufactured by Farfisa and Vox.

Conn-Selmer and Rodgers, dominant in the market for larger instruments, also made electronic organs that used separate oscillators for each note rather than frequency dividers, giving them a richer sound, closer to a pipe organ, due to the slight imperfections in tuning.

Hybrids, starting in the early 20th century, incorporate a few ranks of pipes to produce some sounds, and use electronic circuits or digital samples for other sounds and to resolve borrowing collisions. Major manufacturers include Allen, Walker, Compton, Wicks, Marshall & Ogletree, Phoenix, Makin Organs, Wyvern Organs and Rodgers.

Digital

The development of the integrated circuit enabled another revolution in electronic keyboard instruments. Digital organs sold since the 1970s utilize additive synthesis, then sampling technology (1980s) and physical modelling synthesis (1990s) are also utilized to produce the sound.

Virtual pipe organs use MIDI to access samples of real pipe organs stored on a computer, as opposed to digital organs that use DSP and processor hardware inside a console to produce the sounds or deliver the sound samples. Touch screen monitors allows the user to control the virtual organ console; a traditional console and its physical stop and coupler controls is not required. In such a basic form, a virtual organ can be obtained at a much lower cost than other digital classical organs.

Mechanical organs

Barrel organ: made famous by organ grinders in its portable form, the larger form often equipped with keyboards for human performance

Organette: small, accordion-like instrument manufactured in New York in the late 1800s

Novelty instruments or various types that operate on the same principles. These pipe organs use a piano roll player or other mechanical means instead of a keyboard to play a prepared song:

Orchestrion

Fairground organ (or band organ in the USA)

Dutch street organ

Dance organ

The wind can also be created by using pressurized steam instead of air. The steam organ, or calliope, was invented in the United States in the 19th century. Calliopes usually have very loud and clean sound. Calliopes are used as outdoors instruments, and many have been built on wheeled platforms.

Science Fair Electronic Project Lab + VVVV is good! by Paul Prudence

12 8

Tonight i ditched the glitchcore in favour of the Science Fair Electronic Project Lab for sound generation. There are many circuit set-ups allowing for the generation of all sorts of wonderful sounds including....the 'electronic cat', the 'light controlled electronic harp' a white noise generator, and oh..... a pulse oscillator tone generator.....

I then used these sounds in VVVV for realtime analysis to drive some visuals i made for a VJ set sometime ago.

Geometric Oscillator by Fernan Federici

25 10

Vintage Philips QB 3.5/750 Tetrode Vacuum Tube by Sascha Grant

7 4

This Philips QB 3.5/750 Tetrode vacuum tube is designed for use as a High Frequency amplifier and oscillator. It has an output of around 750 watts!

I received it as a gift some years ago and it's been sitting in a box in want of a new home. Since I'm not going to put it into service, I thought I would make up an acrylic display housing for it, so now it sits in my lounge room where I can enjoy it!

This is a big tube - Really big! The tube is 145mm high x 87mm wide.

Want to see what this tube looks like running? Check out this!

historische-elektronik.piranho.de/Hyperlink%20F/EL6471%20...

This 1000w amp has two :)

I found a data sheet on line with a sketch of the base, so was able to transpose this into CorelDRAW. I lasercut the box with enough clearance for the tube to 'float' in the middle. The Philips logo is engraved into the inside-surface of the sides.

Moog Modular 55 by grobie

Needs your free vote of support at: goo.gl/heBmZ7

With enough votes, it could be made into an actual set by LEGO!

Also, please check out my Minimoog models at: goo.gl/iucWKS

AND

the Prism & Spectrum at: goo.gl/pFTr3v

1 2 3 4 5 6 7 ••• 79 80

Tags oscillator

View allAll Photos Tagged oscillator