Low Signal Stength

A project log for Super Simple MW/AM radio circuit

A one transistor MW/AM radio.

agp.cooperagp.cooper 11/12/2016 at 22:520 Comments

Low Signal Strength?

I assembled the two transistor reflex circuit:

I went with this design as I have built it before and it works.

I did model this circuit in the simulator and the Ge diode can be swapped with a silicon (the diode bias current is about 1.8 uA).

Also the audio output increases as a square of the signal strength (interesting?).

Well the performance was poor, I could just make out a local 720 kHz station.

So I think the circuit is working properly, just low signal?

Here is the reflex:

And here is the DIYLC design:

Th only change was to reduce the 100 uF emitter by pass to to 27 uF (25 uF would have been better) to centre the audio gain at 1 kHz.