On Sun, Nov 15, 2020 at 07:47 PM, Ashhar Farhan wrote:
I am worried that we are losing the skill to produce VFOs.
Hi Ashhar,
Good points on building stable VFOs. Likely any L/C oscillator would benefit from these points. When I was a kid building and experimenting with L/C oscillators and VFOs for radios this was an important part of the radio construction. Easy to forget how to make these correctly now days. Before the days of microprocessors in everything, I remember building a Heathkit audio generator that actually used a small incandescent light bulb to stabilize the output level and keep the waveform a sine wave. I love microprocessors, but still remember and have warm feelings for the analog cleverness of days gone by.
I don't know if this is practical to add to a list of improving oscillator stability techniques, but I was reading one of the earlier links (I believe it was in this group) to an older construction article. The author of that article suggested "annealing" the coils by dipping them in boiling water for a while. The idea seems interesting.?
Tom, wb6b
