Receiver Improvements

A project log for Super Simple MW/AM radio circuit

A one transistor MW/AM radio.

agp.cooperagp.cooper 11/12/2016 at 22:530 Comments

Receiver Improvements

I modelled the Reflex (I could not get the coil tap to work properly but I got a capacitive tap to work):

The input impedance to the first stage is dominated by the diode impedance (~70 ohm).

This explains the 1:10 tap of the original circuit.

As the receiver noise is already high the best way to improve the receiver is with a pre-amp or an impedance matching buffer:

The buffer has a 15k input impedance so no impedance tap is required.