Drone Ranger : 4 Oscillators, 2 white noise sources, 2 ring mod, 2 Fuzz, 2 resonant low pass filters with LFO modulation.

Shown here are the upcoming E340 Cloud Generator and E350 Morphing Terrarium modules by Synthesis Technology (best known for their MOTM line of synth modules). Synthesis Technology is now venturing into Eurorack with the forthcoming release of these two modules in December. They should both be out about the same time. The Cloud Generator contains 8 VCOs with voltage-controlled spread, chaos and chaos bandwidth, amongst other features. The Morphing Terrarium is a wavetable oscillator with two glitch-free outputs and extensive voltage control. Photo credit: Kwote, from the 11/14/09 AH Bay Area Gathering. LINK: kwotemusic.blogspot.com/ .

Woodworking plans available at www.lisaboyer.com

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: Cat behavior

Outdoor cats are active both day and night, although they tend to be slightly more active at night.[88] Domestic cats spend the majority of their time in the vicinity of their homes but can range many hundreds of meters from this central point. They establish territories that vary considerably in size, in one study ranging 7–28 ha (17–69 acres). The timing of cats' activity is quite flexible and varied but being low-light predators, they are generally crepuscular, which means they tend to be more active near dawn and dusk. However, house cats' behavior is also influenced by human activity and they may adapt to their owners' sleeping patterns to some extent.

 

Cats conserve energy by sleeping more than most animals, especially as they grow older. The daily duration of sleep varies, usually between 12 and 16 hours, with 13 and 14 being the average. Some cats can sleep as much as 20 hours. The term "cat nap" for a short rest refers to the cat's tendency to fall asleep (lightly) for a brief period. While asleep, cats experience short periods of rapid eye movement sleep often accompanied by muscle twitches, which suggests they are dreaming.

 

Sociability

The social behavior of the domestic cat ranges from widely dispersed individuals to feral cat colonies that gather around a food source, based on groups of co-operating females. Within such groups, one cat is usually dominant over the others. Each cat in a colony holds a distinct territory, with sexually active males having the largest territories, which are about 10 times larger than those of female cats and may overlap with several females' territories. These territories are marked by urine spraying, by rubbing objects at head height with secretions from facial glands, and by defecation. Between these territories are neutral areas where cats watch and greet one another without territorial conflicts. Outside these neutral areas, territory holders usually chase away stranger cats, at first by staring, hissing, and growling and, if that does not work, by short but noisy and violent attacks. Despite this colonial organization, cats do not have a social survival strategy or a herd behavior, and always hunt alone.

 

Life in proximity to humans and other domestic animals has led to a symbiotic social adaptation in cats, and cats may express great affection toward humans or other animals. Ethologically, a cat's human keeper functions as if a mother surrogate. Adult cats live their lives in a kind of extended kittenhood, a form of behavioral neoteny. Their high-pitched sounds may mimic the cries of a hungry human infant, making them particularly difficult for humans to ignore. Some pet cats are poorly socialized. In particular, older cats show aggressiveness toward newly arrived kittens, which include biting and scratching; this type of behavior is known as feline asocial aggression.

 

Redirected aggression is a common form of aggression which can occur in multiple cat households. In redirected aggression there is usually something that agitates the cat: this could be a sight, sound, or another source of stimuli which causes a heightened level of anxiety or arousal. If the cat cannot attack the stimuli, it may direct anger elsewhere by attacking or directing aggression to the nearest cat, dog, human or other being.

 

Domestic cats' scent rubbing behavior toward humans or other cats is thought to be a feline means for social bonding.

 

Communication

Main article: Cat communication

Domestic cats use many vocalizations for communication, including purring, trilling, hissing, growling/snarling, grunting, and several different forms of meowing. Their body language, including position of ears and tail, relaxation of the whole body, and kneading of the paws, are all indicators of mood. The tail and ears are particularly important social signal mechanisms in cats. A raised tail indicates a friendly greeting, and flattened ears indicate hostility. Tail-raising also indicates the cat's position in the group's social hierarchy, with dominant individuals raising their tails less often than subordinate ones. Feral cats are generally silent.: 208  Nose-to-nose touching is also a common greeting and may be followed by social grooming, which is solicited by one of the cats raising and tilting its head.

 

Purring may have developed as an evolutionary advantage as a signaling mechanism of reassurance between mother cats and nursing kittens, who are thought to use it as a care-soliciting signal. Post-nursing cats also often purr as a sign of contentment: when being petted, becoming relaxed, or eating. Even though purring is popularly interpreted as indicative of pleasure, it has been recorded in a wide variety of circumstances, most of which involve physical contact between the cat and another, presumably trusted individual. Some cats have been observed to purr continuously when chronically ill or in apparent pain.

 

The exact mechanism by which cats purr has long been elusive, but it has been proposed that purring is generated via a series of sudden build-ups and releases of pressure as the glottis is opened and closed, which causes the vocal folds to separate forcefully. The laryngeal muscles in control of the glottis are thought to be driven by a neural oscillator which generates a cycle of contraction and release every 30–40 milliseconds (giving a frequency of 33 to 25 Hz).

 

Domestic cats observed in a rescue facility have total of 276 distinct facial expressions based on 26 different facial movements; each facial expression corresponds to different social functions that are likely influenced by domestication.

 

Grooming

Cats are known for spending considerable amounts of time licking their coats to keep them clean. The cat's tongue has backward-facing spines about 500 μm long, which are called papillae. These contain keratin which makes them rigid so the papillae act like a hairbrush. Some cats, particularly longhaired cats, occasionally regurgitate hairballs of fur that have collected in their stomachs from grooming. These clumps of fur are usually sausage-shaped and about 2–3 cm (0.79–1.18 in) long. Hairballs can be prevented with remedies that ease elimination of the hair through the gut, as well as regular grooming of the coat with a comb or stiff brush.

 

Fighting

Among domestic cats, males are more likely to fight than females. Among feral cats, the most common reason for cat fighting is competition between two males to mate with a female. In such cases, most fights are won by the heavier male. Another common reason for fighting in domestic cats is the difficulty of establishing territories within a small home. Female cats also fight over territory or to defend their kittens. Neutering will decrease or eliminate this behavior in many cases, suggesting that the behavior is linked to sex hormones.

 

When cats become aggressive, they try to make themselves appear larger and more threatening by raising their fur, arching their backs, turning sideways and hissing or spitting. Often, the ears are pointed down and back to avoid damage to the inner ear and potentially listen for any changes behind them while focused forward. Cats may also vocalize loudly and bare their teeth in an effort to further intimidate their opponents. Fights usually consist of grappling and delivering powerful slaps to the face and body with the forepaws as well as bites. Cats also throw themselves to the ground in a defensive posture to rake their opponent's belly with their powerful hind legs.

 

Serious damage is rare, as the fights are usually short in duration, with the loser running away with little more than a few scratches to the face and ears. Fights for mating rights are typically more severe and injuries may include deep puncture wounds and lacerations. Normally, serious injuries from fighting are limited to infections of scratches and bites, though these can occasionally kill cats if untreated. In addition, bites are probably the main route of transmission of feline immunodeficiency virus. Sexually active males are usually involved in many fights during their lives, and often have decidedly battered faces with obvious scars and cuts to their ears and nose. Cats are willing to threaten animals larger than them to defend their territory, such as dogs and foxes.

 

Hunting and feeding

See also: Cat food

The shape and structure of cats' cheeks is insufficient to allow them to take in liquids using suction. Therefore, when drinking they lap with the tongue to draw liquid upward into their mouths. Lapping at a rate of four times a second, the cat touches the smooth tip of its tongue to the surface of the water, and quickly retracts it like a corkscrew, drawing water upward.

 

Feral cats and free-fed house cats consume several small meals in a day. The frequency and size of meals varies between individuals. They select food based on its temperature, smell and texture; they dislike chilled foods and respond most strongly to moist foods rich in amino acids, which are similar to meat. Cats reject novel flavors (a response termed neophobia) and learn quickly to avoid foods that have tasted unpleasant in the past. It is also a common misconception that cats like milk/cream, as they tend to avoid sweet food and milk. Most adult cats are lactose intolerant; the sugar in milk is not easily digested and may cause soft stools or diarrhea. Some also develop odd eating habits and like to eat or chew on things like wool, plastic, cables, paper, string, aluminum foil, or even coal. This condition, pica, can threaten their health, depending on the amount and toxicity of the items eaten.

 

Cats hunt small prey, primarily birds and rodents, and are often used as a form of pest control. Other common small creatures such as lizards and snakes may also become prey. Cats use two hunting strategies, either stalking prey actively, or waiting in ambush until an animal comes close enough to be captured. The strategy used depends on the prey species in the area, with cats waiting in ambush outside burrows, but tending to actively stalk birds.: 153  Domestic cats are a major predator of wildlife in the United States, killing an estimated 1.3 to 4.0 billion birds and 6.3 to 22.3 billion mammals annually.

 

Certain species appear more susceptible than others; in one English village, for example, 30% of house sparrow mortality was linked to the domestic cat. In the recovery of ringed robins (Erithacus rubecula) and dunnocks (Prunella modularis) in Britain, 31% of deaths were a result of cat predation. In parts of North America, the presence of larger carnivores such as coyotes which prey on cats and other small predators reduces the effect of predation by cats and other small predators such as opossums and raccoons on bird numbers and variety.

 

Perhaps the best-known element of cats' hunting behavior, which is commonly misunderstood and often appalls cat owners because it looks like torture, is that cats often appear to "play" with prey by releasing and recapturing it. This cat and mouse behavior is due to an instinctive imperative to ensure that the prey is weak enough to be killed without endangering the cat.

 

Another poorly understood element of cat hunting behavior is the presentation of prey to human guardians. One explanation is that cats adopt humans into their social group and share excess kill with others in the group according to the dominance hierarchy, in which humans are reacted to as if they are at or near the top. Another explanation is that they attempt to teach their guardians to hunt or to help their human as if feeding "an elderly cat, or an inept kitten". This hypothesis is inconsistent with the fact that male cats also bring home prey, despite males having negligible involvement in raising kittens.:

 

Play

Main article: Cat play and toys

Domestic cats, especially young kittens, are known for their love of play. This behavior mimics hunting and is important in helping kittens learn to stalk, capture, and kill prey. Cats also engage in play fighting, with each other and with humans. This behavior may be a way for cats to practice the skills needed for real combat, and might also reduce any fear they associate with launching attacks on other animals.

 

Cats also tend to play with toys more when they are hungry. Owing to the close similarity between play and hunting, cats prefer to play with objects that resemble prey, such as small furry toys that move rapidly, but rapidly lose interest. They become habituated to a toy they have played with before. String is often used as a toy, but if it is eaten, it can become caught at the base of the cat's tongue and then move into the intestines, a medical emergency which can cause serious illness, even death. Owing to the risks posed by cats eating string, it is sometimes replaced with a laser pointer's dot, which cats may chase.

 

Reproduction

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.

Here's a photo of the new Dreamboat, actually three Dreamboats, which are now in-stock.

 

"The dreamboat is a dual chaotic oscillator with 2x cv inputs, a gate output with adjustable threshold, and two sets of x and y outputs. There are two oscillator sections to the module, the top half is an audio rate chaotic oscillator and the lower half outputs lfo rate signals. With its five outputs, the Dreamboat allows you to connect to plenty of modules all at once, allowing all kinds of modulation and listening possibilities."

 

See our webpage for more details.

LINK: www.analoguehaven.com/snazzyfx/dreamboat/ .

 

The Dreamboat is Snazzy FX's first Eurorack module but several more are already planned.

The (harmonic-rich) output from my 80M oscillator. I didn't have the right capacitors on hand, so the frequency is a bit off from the 3.579545 marked on the rock; my spectrum analyzer pegs it at 3.79 MHz, but I hear it in my FT-817 at 3.5775. I'm inclined to believe the '817, as the spec-an complains about a calibration error rather regularly.

A few documentation shots of the multi oscillator, light reactive synths I've been building for various performances as part of Sanctuary 2015. They use the amazingly hardy perennial favourite IC, the 40106 CMSOS Schmitt trigger.

 

There are also a couple of not synths, but percussive instruments made from jars, piezo electric contact mics and m3 nuts and a silver dollar respectively,

National Ignition Facility laser pulses at Lawrence Livermore National Laboratory are born in the master oscillator room, in which a compact laser oscillator generates low-energy (a few nanojoules) laser pulses. The oscillator pulse is shaped in time and frequency-broadened, using the small range of multiple wavelengths produced in the fiber laser, to help smooth the intensity of the laser beam when it is ultimately focused on the target. There are 48 independent pulse shaping systems, and each of the pulses is transported on separate fiber optic cables to 48 preamplifier modules for further amplification.

Yamaha CS-5, Electrocomp-101, Roland SH3.

Sold by Lafayette Radio on Liberty Avenue in "downtown" Jamaica, Queens County, New York. Built from a kit before I was 12. While most of the students were involved with sports, fighting, or stealing hubcaps me and a few of my friends were preteen turbo nerds. We would ride our bicycles the 10 miles into Jamaica and buy electronics parts. Or go to Mineola and buy surplus military equipment and take it home (still in the original wood crate) balanced on the bicycle seat. Or go into lower Manhattan (Cortlandt Street or Canal Street), load up on surplus electronics, and drag it home at rush hour in the subway and then a bus. Hated having to take a bus into downtown Hempstead every week for allergy shots until i found a surplus store near the bus terminal.

 

While basically an AM (amplitude modulation) receiver, it could also be coaxed to decode SSB (single side band) using the built-in BFO (beat frequency oscillator) and FM (frequency modulation) by using "slope detection".

 

Never got murdered - only attacked once on the way to Jamaica for going into a "candy store" that had only a few packs of gum on a card table near the entrance with a partition with lots of phones ringing in the back. Located near Belmont Park Race Track - the locals knew better than to go in. This was before legalized OTB (off track betting) - gambling on horse races was big business.

The diagram shows a device that was suggested to me, by Douglas Little. Prior to using this device, the performance of my laser was very inconsistent. Here is how Doug diagnosed the problem:

 

Each cycle of the pump produces a massive sucking force for a brief period: a big pressure shock over and over, several times per second. Coupled with the AC at 60hz, you have two oscillators running over each other. So the result will be interfering waves. You have electrical AC running at one frequency, and you've got the pump affecting pressure in waves, at a different frequency. When you combine waves of different frequencies, you get a mess. This would appear as changes in efficiency of the laser, and as a random flickering within the electrical discharge. An oscillating discharge is cycling through a range of states, including the 'best' one: a bit like a broken clock being right once every 12 hours. However, a stable laser will be stuck in one state, but it is less likely to be the correct state. As a result of this, the entire apparatus becomes very sensitive to any adjustments that are made.

 

An initial test must be conducted in order to obtain a stable discharge, followed by a second test to optimize the random flickering that will take place. A big jar (capacitor) will help a lot, and a small hole at the laser side of this jar (resistor) will help even more. If laser power seems lower with a stable discharge, then this is an indication that more tuning is needed.

   

Oscillator 2 of voice 1 of my Prophet 600 is a tad wonky. For the first 30 minutes that oscillator keeps quickly drifting out of tune. The CEM3340 chip (lower left) is the problem, however they all go out until the instrument is warmed up, just not as bad as this one. Luckily they have just started making the CEM3340 again so I will soon get a replacement.

Inspired by a Dave Jones video "EEVblog 1178 - Build a $10 DIY EMC Probe"

 

Made 2 EMC probes with approximately 1cm and 1.5cm inner diameter, with RG402 semi rigid cable terminated with an SMA male connector. The probes are not yet finished thought, since I have to dip the probe tips in liquid electrical tape, that I don't have for now. I manage to insulate almost all the probe with heat shrink tube but the soldered part of ring is still exposed.

 

My IDS-2074E oscilloscope, besides the upgraded BW to 300MHz had a recent feature added, Spectrum Analyzer up to 500MHz, and in this photo it's showing the signal radiated from a 100MHz crystal oscillator, captured with the 1.5cm diameter EMC probe. The graph is set with the 100MHz centre frequency and a span of 10MHz.

 

The Spectrum Analyzer option is accessed through the square button "OPTION", on the inferior right corner of the dark area around the LCD. Until now, that button had no purpose.

 

The Wolfcraft clamp is just there to hold the EMC probe over the crystal oscillator being measured.

Woodworking plans available at www.lisaboyer.com

**Cape Henry Lighthouse** - National Register of Historic Places Ref # 66000910, date listed 1966-10-15

 

**Cape Henry (Second Tower) Light Station** - National Register of Historic Places Ref # 02001439, date listed 2002-12-02

 

Atlantic Ave. at U.S. 60

 

Virginia Beach, VA Virginia Beach (Independent City)

 

The Atlantic Coast and Chesapeake Bay served as a major transportation corridor for commercial traffic from the early 18th through 20th centuries. Cape Henry Lighthouse marks the south side of the entrance to Chesapeake Bay and is considered one of the most important lighthouses on the Atlantic coast. The Lighthouse is the earliest cast-iron-cylinder light tower in the state of Virginia; at 163 feet, it is the tallest cast-iron-plate light tower in the United States. The world's first synchronized radio beacon and electric oscillator air fog signal was put into commission at Cape Henry Lighthouse in May of 1929.

 

The construction of the first Cape Henry tower (1792), a National Historic Landmark, was the first public works project completed by the new federal government. In 1872, cracks extending from the base to nearly the top of the tower on the north and south walls were first reported by inspectors, though only eight years earlier the tower was reported "in excellent order." The Lighthouse Board, fearing the structure would collapse, recommended a new and more substantial lighthouse be built of the first order since it was considered "one of the first lights of importance along the coast." It was also noted that the 30-year-old frame keeper's dwelling was in a "dilapidated condition," too small for the number of keepers stationed there, and too far from the tower to insure "proper attendance." An estimated cost for the new tower and quarters was $85,000 with a request to Congress for $50,000 to commence work. This request was renewed in 1873 and 1874. In 1875, the request was raised to $75,000 and renewed again in 1876. Congress finally appropriated this amount on June 20, 1878. In 1878, the Board requested an additional $25,000 which was renewed in 1879 and, finally, appropriated on June 16, 1880. A second request for still another $25,000 was appropriated on March 3, 1881, to complete the lighthouse station. Of these two additional appropriations, $48,063.52 was spent in 1882. (1)

 

References (1) NRHP Nomination Form www.dhr.virginia.gov/wp-content/uploads/2018/04/134-0079_...

Bush DAC90a host with Roberts R500 lw/mw/sw chassis.

14/5/14 updated version with Roberts R500 front end (mixer / oscillator AF117 replaced with AF138) feeding a Hacker IF strip from a RP25 and a Hacker audio amp (Rp25 again.)

Now with Hacker FM IF card added to underside of Bush chassis fed from a Varicap tuned Larsholt tuner head.

22k lin pot attached to AM tuning capacitor.

Tunes from 88 to 108 which is one reason why i didnt use the hacker tuner i had (88-102) also the larsholt has dualgate mosfets and varicap tuning and is noticably more sensitive.

Woodworking plans available at www.lisaboyer.com

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

subatomic Midibox SID V2

synthesizer in old vintage commodore c64 computer case

read about this DIY project here in the work blog: www.subatomicglue.com/sidl0g/

 

for information about making your own midibox go here: www.ucapps.de/midibox_sid.html

  

This is a MidiboxSID, a synthesizer that has sound chips from the original commodore 64 personal computer from the 1980's. These sound chips are called the SID 6582

 

The synth is built into an original Commodore 64 computer case. And features 8 SID chips (4 stereo pairs - one SID per ear x 4 voices). Each SID chip has 3 oscillators and a variety of other features like filters, ADSR, ringmod, sync. The synth has a very flexible (and simple to use) modulation matrix, LFO, bassline sequencers, and stores patches in presets.

  

UPDATE:

 

2008-05-28 We got midibox of the day! and also covered on the midibox.org's blog

2008-06-02 matrixsynth covered this story

2008-06-05 hack a day covered this story with their own synopsis of the build process!

1988

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

Picture format: 24mm x 36mm standard 35mm film format.

Lens mount: Nikon F mount.

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 detectionrange: EV minus 1 to EV 19 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 (75/25) and spot metering.

Metering range: EV 0 to 21 for matrix and (at 100 ISO centre-weighted; EV 4 to 21 for spot with f/1.4 metering. lens):

Exposure meter: Activated by lightly pressing the shutter release button; stays on for approx 8 sec after finger leaves button.

Exposure modes: Programmed auto-multi, shutter-priority auto, aperture priority auto and manual.

Programmed auto exposure control: Both shutter speed and aperture are set automatically; 1 EV increments of aperture is possible.

Exposure compensation: Use exposure compensation button within +/- 5 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; electromagnetically controlled long exposure at B setting.

Viewfinder: Fixed eyelevel pentaprism high-eyepoint type; 0.75x magnification with 50mm lens at infinity; 92% frame coverage.

Eyepoint: 19mm approx.

Eyepiece shutter: Provided. (DK-8)

Focusing screen: Fixed Nikon advanced B-type screen BriteView screen; interchangeable with E type screen.

Viewfinder information: Focus indications, exposure mode, shutter speed/ISO, aperture/exposure compensation, electronic analogue display, exposure compensation mark and flash-ready are all shown in LCD readout; also shows flash recommended/ready light LEDs.

LCD panel information: Shutter speed, aperture, exposure mode, metering system, film speed, DX mark, electronic analogue display, exposure compensation mark, frame counter/self timer/multiple exposure, exposure compensation value, film advance mode, film loading, film rewind, self timer.

Viewfinder/LCD panel illumination: Viewfinder and LCD panel illuminated by pressing button.

Film speed range: ISO 25 to 5000 for DX-coded film; ISO 6 to 6400 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 or continuous low shooting modes, shots are taken as long as shutter release button is depressed; high speed 3.3 fps; low 2.0 fps.

Film rewind: By pressing buttons with red rewind markings simultaneously; rewind stops auotmatically when film is rewound.

Frame counter: Additive type; counts back while film is rewinding.

Self-timer: Electronically controlled; timer duration selectable from 2 to 30 seconds in one second increments; 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.

Camera back: Hinged; interchangeable with Nikon Multi-Control Back MF-21 or World Time Data Back MF-20.

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.

Number of 36 exposure film rolls per set of fresh batteries:

Battery 20oC -10oC

Alkaline 105 15

Manganese 25 3

Ni-Cd 75 22

Power source: Four AA alkaline, Ni-Cd or manganese batteries.

Battery check: Battery power confirmation as full battery sign; half battery for nearing exhaustion; blinking half empty battery sign indicates batteries are just about exhausted; no indication appears when batteries are completely exhausted or improperly installed.

Dimensions (W x H x D): 154 x 103 x 67mm approx.

Weight (body only): 695g approx.

Rudis Sylva – RS 16 Harmonious Oscillator

12/1/11. Portland, Oregon. Riding to work. Nikon Coolpix S8100, handheld and sooc.

 

1000 5/3/15.

 

LEFFER VRM 2500 OSCILLATOR

The Leffer hydraulic casing Oscillator has over 8 million ft-lbs of torque and 580 tons of extraction force. This

machine is capable of drilling over 200 ft deep with a 2.5M oscillator casing.

This machine is used in caving soils where the bore hole requires casing to the bottom of the hole.

New from Bubblesound and now in-stock, the VCOb. Not only does it sound awesome but its also very affordable. This is a great oscillator to start with when building a Eurorack system as they're compact, priced well, plus have lots of features and character. They also have their place in larger systems. The tuning is solid and the module can do both linear and exponential FM.

 

Yes, the module is 8 HP.

 

LINK: www.analoguehaven.com/bubblesound/vcob/ .

Woodworking plans available at www.lisaboyer.com

Logitech LS1 Laser Mouse

 

Sensor Markings:

S7550

80826T

2AV

 

Looks like this one is an ADNS-7550: www.avagotech.com/pages/en/navigation_interface_devices/n...

 

The controlling chip+USB interface:

CY7C63813-PXC

C56632AF

PHI0837 A O4

647813

 

It's a Cypress Semi part:

www.cypress.com/?rID=14212

- has an internal oscillator (yay!)

- 8K Flash/256 Bytes RAM

 

Assuming it can be wiped & reprogrammed with the Cypress PSoC tools, there's some serious hack potential here! Change some of the buttons into sockets and soft-configure as outputs.

Super portable Arduino-compatible thing.

- 3xAAA battery-powered

- RGB LED on PWM pins

- 38kHz IR remote receiver

- ATmega8 w/ internal oscillator running @8MHz

- old Arduino bootloader w/ fuses set to not need ext. crystal

- 15mA idle current

- fits in pocket

- causes small amounts of glee

Released as a 'single for Oscillator Sunshine Machine - "I Love You Too"

Antenna is designed to receive the WWVB time and frequency signal from the National Institute of Standards and Technology (NIST) in Ft Collins, CO.

 

Simple set up... just aim the antenna toward Colorado using the arrow. Works great indoors in Upstate NY. Not need to mount it outside (it is weatherproof). Will accept long cable runs without a preamp due to the 60 kHz frequency.

  

WARNING: Spectracom receivers extract the carrier from WWVB using a PLL to discipline a local oscillator. The new phase modulation scheme, to be activated by NIST in July, 2012, does not allow carrier extraction in this manner... and impacts the ability to decode time-of-day reliably.

 

Translation: Netclock/2 (and other Spectracom WWVB receivers) will fail. It will unlock from "time sync" and begin freewheeling when the change is initiated. The good news: cheap consumer clocks will work better.

A free application by Jacek Fedorynski. It works well even with me using the key.

The Science Museum of Minnesota has a wave generator. You can adjust the frequency and amplitude of the oscillator that generates the waves. You can also tinker with the "seafloor" profile. I found that a large amplitude, low frequency oscillation, combined with a gradual decrease in "sea" depth led to the biggest and most clearly defined waves.

 

As of 20 Dec 2013, this is, by far, my most viewed image in Flickr. I have no idea why.

Description: A student is being shown how to locate underground telephone cables by using a search coil and tone oscillator.

 

Location: Pakistan

 

Date: 1954-1955

 

------------------------------------------------------

 

Our Catalogue Reference: Part of CO 1069/514.

 

This image is part of the Colonial Office photographic collection held at The National Archives. Feel free to share it within the spirit of the Commons.

 

Please use the comments section below the pictures to share any information you have about the people, places or events shown. We have attempted to provide place information for the images automatically but our software may not have found the correct location.

 

For high quality reproductions of any item from our collection please contact our image library

 

040304 {yymmdd}

The next Eurorack module from Macbeth Studio Systems will be the Oscillator. More than just one half of the Dual Oscillator, this single module retains the full and rich sound of the original but offers a wide range Osc Sweep knob as opposed to the octave switch while still using the luxury multi-turn fine tuning pot. It also has a switch to put it into LFO mode as well as two seperate sub oscillator outputs- in addition to all the standard waveform outputs.

 

We expect the X-Series Oscillator in early January for a price around $699. The size is 21 HP. For those who already have a Dual Oscillator, it makes a perfect third oscillator/modulator for that classic "Minimoog voice".

 

LINK: www.analoguehaven.com/macbethstudiosystems/ .

Listen to this synth here: www.wiretotheear.com/2011/11/19/analogue-solutions-telema...

Woodworking plans available at www.lisaboyer.com

"Experiments with differently attuned coils, and responding to the vibrations transmitted to them through the earth from an electrical oscillator. The large coil on the right, discharging strongly, is tuned to the fundamental vibration, which is fifty thousand per second; the two larger vertical coils to twice that number (...) and the remaining small coils to higher tones..."

www.diyaudio.com/community/threads/asynchronous-i2s-fifo-...

 

1.To compare phase noise, oscillators have to be at the same frequency.

 

2.45.1584MHz is selected for the comparison because 45/49 MHz clocks can cover the full digital audio ranges from 44.1 to 384KHz

 

3.SC-Pure phase noise was measured recently by a calibrated E5052 phase noise analyzer from a third party.But all other phase noise numbers are collected from published datasheets or websites.So please correct me if there is anything wrong.

 

4.No doubt, phase noise numbers have a big impact on the DAC sound quality, but it may not be 100% related.It could be because of the limitation of the fundamental frequency only phase noise measurement method. DAC runs by the square wave clock, not the sine wave. However, each harmonic frequency has its own phase noise and they all contribute to the final phase noise of the square wave clock. That’s why clocks with the similar phase noise numbers could still sound differently.

 

5. I could be the one who did the most listening tests to different clock oscillators besides Doede. Based on my own experiences of the listening tests, I've found that the close-in phase nose, the phase noise floor and the phase noise in between (Leeson’s equation applied) are all significant to the sound quality. An oscillator can not achieve a higher grade sound quality if it doesn’t have good close-in phase noise even though its noise floor is great. On the other hand, a good close-in phase noise oscillator can also sound a bit fat, less sound stage any dynamic if the noise floor or the phase noise in between are not great.

 

6.45.1584MHz Neutron Star2 is a pretty expensive clock. But I found it just uses a fundamental non SC-CUT cut crystal (not the 3OT SC-CUT) . It does have a heater on the PCB but just to keep the crystal temperature stable at around 40 degree C regardless of the ambient temperature. Don’t know why NewClassD didn’t publish the phase noise specifications.

 

7. Normally SC-Cut crystal oscillators have both better overall phase noise performance and better sound quality than AT-Cut crystal oscillators.

 

8. Limited by the noise floor of a phase noise analyzer, oscillators with great far off phase noise may not correctly show from the measurement results.

The birthplace of Silicon Valley, as stated in the sign, the garage barely visible in the background is the famed location where Stanford electrical engineering students Bill Hewlett and David Packard agreed to form the company Hewlett-Packard in 1935 (the order of the names decided by a coin toss). Influenced by Professor Frederick Terman, they decided to start their own company instead of moving East to join a large business corporation. In 1939, the pair designed the HP200A low-distortion audio oscillator, with an innovative negative feedback loop using a thermal resistor in the form of a cheap light bulb. The oscillator was purchased by Walt Disney for certifying surround sound in the movie Fantasia. The success of HP made students running companies in garages a popular trope, though ironically property values are now so high around Professorville ($1.8 million median) that no student could reasonably be expected to do so in the area.

Downtown Palo Alto, California

 

the dds-60 kit is now built. untested but fully built.

 

about 2 hours (maybe more) to solder this. nothing was hard about it and it was almost fun. a surface mount trimmer pot was interesting. having some parts not on the board (later rev) gives extra confusion.

 

the packing and numbering of parts was very well done. someone put a lot of good thought into it and I can tell.

 

this project - along with an adaptation of mine will be to add support for this in my volumaster C code base on the LCDuino-1. a multi-tester with buttons, knobs, displays and even programming ports (wired and wireless!)

 

this was the A+ style kit that I used to build this. VERY impressive packaging on that kit!!

 

www.flickr.com/photos/linux-works/6979840237/in/photostream

A shot of the control surface of a Roland Juno 60 synthesizer. This particular synth was produced around 1983 and featured analog oscillators which were digitally controlled to aid in tuning stability. The sound of this board is absolutely classic.

Wonderwerp #58

Studio Loos, Den Haag

 

I was educated as a classical pianist, as which I had to follow a rigid regime regarding the piano literature I had to practice, the harmonic and melodic framework I exercised, and the physical posture I had to train, whereby I had to focus mainly on the position of my hands in relation to the piano keys. The piano repertoire I became most familiar with includes Bach, Beethoven, Mozart, Liszt, Chopin, Debussy, Webern and Schoenberg. Improvisation was not part of my training, at all. But the urge to create something unique and new in music brought me to explore improvisation. While improvisation typically is not part of a classical instrumental training, it can be a powerful tool to free oneself from any musical dogmas. As an improviser I started a process of deconstructing the deeply embedded classical repertoire within myself, and came to add electronics in a very personal way.

 

Maia Francisco is a pianist, graphic designer and sound artist. She studied art and design at Barcelona’s Escola Massana Centre d’Art I Disseny and piano at the city’s Conservatory of Music. Maia is currently enrolled as a student of Sonology at the Royal Conservatoire of The Hague, where she researches the use of pure sine waves in music. She is investigating improvisational environments that will allow her to interact with the acoustic piano and sine wave oscillators.

Truetime NTS-200 Network Time Server with optional rubidium oscillator, shown with weatherproof 12 volt active GPS antenna.

 

The term 'Network Time Server' applies to a network appliance that acquires time from an external source (usually GPS atomic clocks), maintains time in its internal local clock, and supplies accurate time to a network using NTP (network time protocol).

 

TrueTime was acquired by Symmetricom.

 

A Stratum 1 time source.

The Pulse Witch 23 electronic sound box.

Demo video : www.youtube.com/watch?v=Tdb6NEecAUU .

 

This box is based on a "pulse width oscillator" circuit, wherein the 4 basic parameters can be adjusted manually or automatically (the latter via LFO or external CV). The idea is that it can be played performatively, or used as a standalone installation. The range section is a bit more complicated: 8 different capacitors can be selected manually via the 3-bit switches, or pseudo-randomly, at a rate that can be controlled manually or automatically.

 

The cool feature of course is the infinity mirror. The LEDs therein echo the state or value of the various sections, e.g. oscillator rate, feedback level and range choice. The meters show the internal voltage level ultimately controlling the speed of the oscillators.

 

For Burroughs and the "23 enigma" watchers... the heart of the circuit uses a CMOS 4023 chip, the range on the meters go from 2 to 23 (in prime numbers).

 

Completed November 2013.

 

My page about my handmade electronic sound boxes with info/demos is here: www.jamesschidlowsky.ca/electronics.html.

 

Back together again and working (except for the strobe, which unfortunately appears to be dead - don't hear the oscillator whining when I switch it on). I have another small strobe I can slip into its adapter if I like, though flash seems inappropriate for this type of camera, it would kind of blow the 'covert' thing.

 

This is a more complex and sophisticated camera than I had expected. If it weren't for the 2-speed shutter, this would have been the top of the Minolta-16 lineup. Even that made sense in the context of the design, though: the meter was set up so that you would dial through the apertures at one speed, if it wasn't enough then you would change speeds and keep going. Having just 2 speeds spaced 3 stops apart makes this simpler than having a bunch of intermediate speeds that you would never use.

A few days ago I found out about a plasma effect that turned out to be easy to duplicate (since I had most of the parts needed). Basically the globe is a low pressure xenon globe (with some oxygen contamination ie green). The circuit driving the loop of wire is a ~10MHz oscillator running at about 19V and 3 amps.

 

The oscillator sets up a field that is not enough to ionize the xenon. I used a HV vacuum leak coil to ionize the globe. The mystery is why it forms a stable toroid.

 

In this video the loop is at the bottom of the globe. The ionized ring is hot, rises to the top of the globe and at some point loses enough energy (because it's getting farther form the coil) and flames out. A new toroid then forms and rises like a smoke ring and decays.

 

Why the toroid forms in the first place is not something I can explain. I also like the little noises it makes as the toroid forms.

The BG 24 H rotary drilling rig is ideally suited for:

 

Drilling cased boreholes (installation of casing by rotary drive or optionally by hydraulic oscillator – both are powered by the drilling rig).

 

Drilling uncased deep boreholes that are stabilized by drilling fluids.

 

Drilling boreholes with long hollow stem augers (CFA system), with or without kelly extensions.

 

Special drilling systems, such as FOW piles, displacement piles, single mixing walls, and cutter soil mixing.

 

Rotary Drive KDK 250 K Metric Standard

Torque 237 kNm 174,811 ft. lbs.

Maximum Speed Of Rotation 32 U / Min. 32 rpm

Crowd System

Chain Driven Crowd

Crowd Force Push 330 kN 74,187 lbf.

Crowd Force Pull 330 kN 74,187 lbf.

Stroke (Kelly Bar System) 9,150 mm 30 ft

Maximum Stroke Of Sledge 15,620 mm 51.2 ft

Main Winch

Line Pull (1st Layer) Effective 200 kN 44,962 lbf.

Line Pull (1st Layer) Nominal 250 kN 56,202 lbf.

Rope Diameter 28 mm 1.1 in.

Rope Length 75 m 246.1 ft.

Maximum Line Speed 85 m / min. 278.9 ft. / min.

Auxiliary Winch

Line Pull (1st Layer) Effective 80 kN 17,985 lbf.

Line Pull (1st Layer) Nominal 100 kN 22,481 lbf.

Rope Diameter 20 mm 0.79 in.

Rope Length 50 m 164.1 ft.

Maximum Line Speed 55 m / min. 180.5 ft. / min.

Maximum Pile Diameter 1,700 mm 5.6 ft.

Drilling Depth Standard 25.5 m 83.7 ft.

Drilling Depth Maximum 57.8 m 189.6 ft.

Base Carrier: BT 75

Engine: Caterpillar C 11

Rate Output ISO 3046-1 313 kW @ 1,800 rpm 420 hp @ 1,800 rpm

Hydraulic Power Output 235 kW 315 hp

Hydraulic Pressure 320 bar 4,641 psi

Operating Weight 82.5 t 181,913 lbs.

Overall Height 21.9 m 71.9 ft.

  

www.bauerpileco.com/en/

Woodworking plans available at www.lisaboyer.com