clifto ) writes:
COLIN LAMB wrote:
Ok, finally found a single tube 100 kHz. crystal oscillator that uses a neon
bulb relaxation oscillator that is synchronized to achieve 10 kHz signals.

Phase Locked Lightbulbs?

Well no, because there's no loop.

It wasn't uncommon to inject a bit of signal from one source to an
oscillator to synchronize them.

That's what was used in oscilliscopes that didn't have triggered
sweep.

I seem to recall that's what was used to synchronize TV set
vertical sweep to the incoming signal.

THere were lots of examples.

PLL's were too costly and complicated during the tube era for
common use, and any real referenfes to PLLs in the hobby magazines
didn't arrive till the late fifties.

Early seventies, and they were all over the place, because ICs
had made them a lot more practical. ANd I suppose there was
suddenly a need; after all, most of the early PLL synthesizers
described in the ham magazines were for 2M FM use, where crystal
control was used in virtually all rigs, but the cost was too
much when you wanted a lot of channels.

Michael VE2BVW