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?

--
One phrase that explains 99% of all idiot driving:
"You can't block traffic if you're not in the way."

clifto wrote:

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?


Not really so bizarre; there are stories of certain computers with light-
sensitive neon bulbs in the logic that were affected by ceiling fluorescent
lighting when panels were removed from the racks...

Regards,

Michael

On Sat, 29 Sep 2007 02:12:13 -0500, msg wrote:

clifto wrote:

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?


Not really so bizarre; there are stories of certain computers with light-
sensitive neon bulbs in the logic that were affected by ceiling fluorescent
lighting when panels were removed from the racks...

Regards,

Michael
The trigger point does shift with light or RF. Black paint on the lamp
will take care of the light.

In my "junk that should have been thrown away" I have a frequency
counter that I built from an artical in QST many years back that used
10 neons per digit. Many years after the fact I realized that it might
have been more practical if the Neon high voltage had been gated off
during the counting phase and on only to display the count. But then
it would not have looked nearly as impressive during operation.

John Ferrell W8CCW
"Life is easier if you learn to
plow around the stumps".

The neon bulb was a wonderful device for a young boy to play with - and for
those that do not entirely grow up. It energized at about 60 volts,
although that varied from tube to tube. ARC-5 receivers used them across
their input, to discharge static electricity. They were great for hams with
meager funds since you could place one near the final and determine if there
were parasitics, by the color of the glow.

Sensitivity could be increased by putting a dc voltage on the plates just
under what it took to fire. Then, a slight amount of rf would add to that
base and fire the bulb.

Little pocket testers would distinguish between ac or dc, by simply looling
to see whether one or two plates were lighted.

Light wuld affect the sensitivity, as well as heat. You could apply a
voltage just under the firing voltage, then put your finger near it and it
would light.

Although I never built one, it probably would have made a great lightning
indicator, with directional probes connected to indicate which quadrant the
lightning was coming from.

As I recall, we used to salvage neon bulbs from old flouroscent light
starters.

And, of course, they were good for neutralizing those old triode finals.

73, Colin K7FM

"clifto" wrote in message
...


Phase Locked Lightbulbs?


There was a circuit where numerous NE2s were wired on the circumference of
a circle as individual relaxation oscillators. At first, the firing pattern
was
entirely random, but over time the lamps would synchronize and fire in
order!
The light from an adjacent lamp would lower the firing point the one next to
it.

Pete

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