Ron,
This is probably because of ceramic capacitors being used the oscillator stages. Components that determine frequency must be ultra-stabe. Use NP0 caps, brown ceramics with a black top. You can also use polystyrene, they are transparent plastic with a silver foil visible inside. They were only available in the old days in small pF values less than 5Kpf.
I usually pour bees wax on top of oscillator components to keep them thermally isolated and keep them from shaking.
Avoid ceramic caps in audio stages, it causes microphonics. Tap them and you will hear a thump in the speaker/transmission. Use mylar/polyester.
Do not use mylar/polyester type caps in RF stages for bypass, instead use ceramic. Polyester work well in audio for coupling.
Ceramic = brown round disks
Polyester/Mylar = green like a chewing gum with leads.
Hope I have not confused you..
73 Raj
vu2zap
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MHz IF will give the proper range) Frequency range seems to be ok but
stability is bad. After 20 minutes waiting freq shift of 1 KHz still
exists. I think I will order some components for a HuffAndPuff
circuit for stabilizing purposes.
