Radio circuit diagrams

A Bipolar Regenerative Receiver

Schematic for the 530 kHz to 1650 kHz AM Broadcasting Band.

UHF Preamplifier

This circuit is designed to work at UHF frequencies in the range 450-800MHz. It has a gain of around 10dB and is suitable for boosting weak TV signals.

MK484 Radio with Loudspeaker

A complete AM radio set based on the MK484 IC (formerly ZN414).

ZN414 Portable Receiver

An AM portable radio receiver made from the ZN414 IC. The ZN414 ic has now been replaced by the MK484 which is identical in performance and pinout.

AM Transmitter

An AM voice transmitter with variable tuning. The antenna circuit is also tuned and transmits via a long wire antenna.

Simple Field Strength Meter

This Field Strength Meter is simple and also quite sensitive. It uses an ordinary digital voltmeter to measure RF signal strength up to a few hundred MHz.

Field Strength Meter

This is a wide band signal strength meter circuit which responds to small changes in RF energy, designed to be used for the VHF spectrum and will respond to AM or FM modulation or just a plain carrier wave.

FM Transmitter

A small FM voice transmitter for Band 2 VHF