If Transformer 455khz

Ne604 Circuit

With only the emitter of the first stage bypassed, the amplifier is stable with about 23 dB gain. The second mixer is Mini-Circuits SRA-1A and again, a similar doubly balanced mixer could be made from discrete diodes and transformers. The VCO is copied from a VFO in the 1989 ARRL Handbookand modified for varactor tuning. The tuned circuits were scaled from their original values for 5 MHz to tune to 7.8135 MHz. The varactor is a small one of unknown type that was on hand....