[HomeBrew] VFO inductor

[Loren Moline WA7SKT]

Hello,
I got my 40 meter direct conversion receiver out that I built years ago and wanted to relate a couple things I did in construction.
When I built the VFO I used a 42IF129 10.7MHz IF transformer as the inductor. Because I purposely had a high capacitance divider in the colpitts oscillator there was no way this coil would resonate at 40 meters. What I did was solder another variable inductor in parallel with it with a value such that I could put the VFO in the 7 to 7.3MHz range.
This may sound like it was different but all I know is that the VFO is stable as a rock. So much fun to use the theory of parallel inductors and the resultant inductance.
Also I used a MC1496 for the product detector and it beats any other circuit I have ever used. Needs a lot of support components but it sure was worth it. It runs circles around the NE602.
If anyone wants the reference for the product detector circuit you can e-mail me. Thanks!

Loren Moline  WA7SKT

Member: Pacific Northwest VHF Society and ARRL
Member: Hearsat Satellite Monitoring Group.  www.uhf-satcom.com
Member: CVARS-Chehalis Valley Amateur Radio SocietyStarchat IRC: Channel = #hearsat
RF Electronics: Starchat IRC: Channel = #rfelectronics
Grid: CN86mr