Circuit diagram

I don't want to bore anyone with a never ending description of the circuit. Just to say the received 198kHz from the tuned loop antenna is amplified by the first transistor, detected by the biased diode and further amplified by the following two transistors. Audio is developed across the 64 Ohm loud speaker.

 

Component list

Reistors

3M3 x 2

150K x 1

100K x1

4K7 x 2

Ceramic capacitors

220pF x 1

1N x 1

10N x 1

100N x 1

Electrolytic capacitors

2200UF x1

220UF x1

10UF x1

Semiconductors

BC109C x 3

1N4148 x 2

Misc and hardware

3/30pF trimmer x 1

Battery holder x 1

PP3 clip x 1

Tinned copper wire 1 metre

Enamelled wire 70 metres

PVC wire 300mm

Speaker 64 Ohm x 1

Hex spacers x 2

3mm screws csk x 4

3mm screws pan head x 2

3mm nuts x 2

Self tapping screws x 6

 

If you are having dificalty obtaining these parts they are available as a pack on out website.

www.kitradio.co.uk/page8.htm

Done