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MrBungle · 27th Jan 2018, 1:15 am

Final statistics for the night:

Version 1 - Colpitts stolen from G3RJV "sudden". Spectrum 2u6L coil + 2n3819 @ 7MHz

Version 2 - Colpitts fixed defective coupling capacitor. Specturm 2u6L coil + 2n3819 + buffer amp. @ 7MHz

version 3 - hand wound air cored coil + 2n4416. Design as per W1FB design notebook. @ 6MHz

Not sure why version 1 and 2 were as miserable as they were!

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Next plan is to crank it down to around 3MHz and see how stable it is there. Then mix with a 4.915MHz crystal oscillator and bandpass it to give a stable 40m VFO. And then see if I can add varactor tuning to the lower frequency oscillator. And then huff puff no doubt.

27th Jan 2018, 1:15 am	#17
MrBungle Dekatron Join Date: Jun 2016 Location: London, UK. Posts: 3,687	Re: Compensating for VFO drift Final statistics for the night: Version 1 - Colpitts stolen from G3RJV "sudden". Spectrum 2u6L coil + 2n3819 @ 7MHz Version 2 - Colpitts fixed defective coupling capacitor. Specturm 2u6L coil + 2n3819 + buffer amp. @ 7MHz version 3 - hand wound air cored coil + 2n4416. Design as per W1FB design notebook. @ 6MHz Not sure why version 1 and 2 were as miserable as they were! Next plan is to crank it down to around 3MHz and see how stable it is there. Then mix with a 4.915MHz crystal oscillator and bandpass it to give a stable 40m VFO. And then see if I can add varactor tuning to the lower frequency oscillator. And then huff puff no doubt.