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Old September 27th 07, 05:21 AM posted to rec.radio.amateur.homebrew
Mark Zenier Mark Zenier is offline
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First recorded activity by RadioBanter: Jun 2006
Posts: 237
Default Xtal calibrator, 1980 ARRL Handbook

In article ,
Michael Black wrote:
do you have a link for using a neon lamp as a frequency divider? This is
the first reference I've seen for this, and I'm fascinated to learn more
about it.

Peter


When I saw Colin start to suggest a tube calibrator, my thought was
"what will you use for a divider, a neon bulb?"

But like him, I can't put my fingers on a circuit. Undoubtedly
somewhere someone did build a crystal calibrator with a neon divider
to get closer together markers, before there were IC dividers.

Another common place would be electronic organs, they'd use neon
bulb dividers to get the next lower octave from a master oscillator.

I'm sure in those "101 things to do with Neon Bulb" books, or even
the wide coverage articles in the magazines, would have a divider.


There's a section in my GE "Glow Lamp Manual" on neon dividers.


sync in -------------+
|
250 V ----/\/\/\---+---|*|-----+------|*|-----gnd
5.6M | n1 n2
|
+------|(-----+-------|(----gnd
| c1 | c2
| +------- output
|
|
+------|(-----+-------|(----gnd
c3 | c4
+------- sync output

C2 = 10 * C1 (For 200 Hz output, .005 and .05 uF)
C3 = C4 = 100 pF

The problem here is that neon bulb relaxation oscillators top out
at, according to the charts in the book, at between 10 and 30 kilohertz,
depending on bulb type.

Mark Zenier
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