Using NE2 bulbs as voltage regulators

[Geoffrey S. Mendelson]

I am building an experimental radiation detector. Being an experiment, I
want to avoid buying anything for it. Sort of a junkbox project to see
what could be done using the parts I have.

The geiger muler tubes I have require 400 volts. I could do it easily buy
buying 200 volt zener diodes and put two in series. Or I could buy a 400
volt gas discharge tube from a Soviet geiger counter cheaply.

But I have neither.

What I do have is 50 NE2 bulbs with resitors. Could I use those?

It would probably take 5 or 6 in series to do it, which compared to two
5 cent zeners from eBay seems like a waste of money and circuit board real
estate, but I am looking to do something that does not require me to
order anything from anyone.

TIA

Geoff

--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379

[tabb...@gmail.com]

Neons wre used as volt reg references in the valve days. Just beware that V is far higher until it strikes, so your following stage should ramp up. And keep the neon in the dark to avoid erratics. And keep current down to avoid failure. And smooth their output well, they get get a bit messy years down the line.


NT

[tabb...@gmail.com]

Voltage overshoot could maybe be reduced wth high R resistors from V_in_+ to various points in the neon chain.


NT

[Bill Sloman]

On Sunday, 9 August 2015 14:49:07 UTC+10, Geoffrey S. Mendelson wrote:
> I am building an experimental radiation detector. Being an experiment, I
> want to avoid buying anything for it. Sort of a junkbox project to see
> what could be done using the parts I have.
>
> The geiger muler tubes I have require 400 volts. I could do it easily buy
> buying 200 volt zener diodes and put two in series. Or I could buy a 400
> volt gas discharge tube from a Soviet geiger counter cheaply.
>
> But I have neither.
>

> What I do have is 50 NE2 bulbs with resistors. Could I use those?

>
> It would probably take 5 or 6 in series to do it, which compared to two
> 5 cent zeners from eBay seems like a waste of money and circuit board real
> estate, but I am looking to do something that does not require me to
> order anything from anyone.

Apparently neon bulbs need 90V to start conducting and settle to about 60V at their rated current. Six or seven of them in series would give you 360V or 420V. You'd need better than 630V to drive a seven lamp string into conduction, and your series resistor would be dropping 210V after they'd turned on. 100uA should be enough current to keep them glowing, so the resistor would have to dissipate at least 20mW, which should not be a problem. Getting the extra 200V might be a pest.

http://www.bristolwatch.com/ele/neon.htm

Zener diodes don't need extra voltage to get them conducting, but you do need enough voltage headroom to cope with their temperature dependence - about 0.13% per degree Kelvin - about 5% over the 40C "room temperature range" or 21V in your 400V, on top of the +/-5% tolerance - another 20V - on the zener voltage. The data sheets typically use 5mA tests currents (which is high - 10W - for a 200V part). The 3W Motorola 1N5956B

http://www.farnell.com/datasheets/112148.pdf

at least specifies the zener impedance at 0.25mA and shows a plot of voltage versus current.

You'd still need about 20V headroom above the worst case 440V for a simple series resistor based shunt regulator. You could do better with a PNP constant current source to provide a constant current through the Zener string, which would work fine with only only a few volts of extra headroom.

--
Bill Sloman, Sydney

[jurb...@gmail.com]

Ever see the designof alotof 1990s DC regulators ? they use a Zener with a voltsage divided down reference.

I you want to stick with tubes, a constant current source is not all that hard. you could make one neon cancel out the other actually. From there it is a simple feedback circuit. I could do it, IF I understand what you want properly.

One thing though, I owuld suggest a lead cage for the neons and any other sensitive tubes. you might geet away with steel actually if you don't go digging around Fukushima, but it depends on how much accuracy you want.

[Jeff Liebermann]

On Sun, 9 Aug 2015 04:49:03 +0000 (UTC), "Geoffrey S. Mendelson"
<g...@mendelson.com> wrote:

>What I do have is 50 NE2 bulbs with resitors. Could I use those?
>
>It would probably take 5 or 6 in series to do it, which compared to two
>5 cent zeners from eBay seems like a waste of money and circuit board real
>estate, but I am looking to do something that does not require me to
>order anything from anyone.

The last time I tried to use a neon lamp as a voltage regulator, I
managed to build to perfectly functional relaxation oscillator
instead. Try googling for a GM power supply schematic:
<https://www.google.com/search?tbm=isch&q=geiger+counter+power+supply+schematic>
See any that use neon lamp regulators? That should be a clue.

My antique CDV-900 counter uses a 900v regulator tube made by
Victoreen.
<http://www.logwell.com/tech/dhdwe/HV_woes.html>
<http://www.logwell.com/products/Codatron_Corotron.html>
There's a difference between these and neon lamps, but I don't recall
the details. The designer of these replacements is someone that posts
regularly to this newsgroup.






--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[Tim Williams]

Sure, but why? Where are you generating the voltage from in the first
place?

If it's from a big iron transformer and rectifier, or a hand-cranked leather
and glass apparatus... it's probably a good idea to regulate (or at least
filter heavily)!

If you're starting with battery power, you're much better off using an SMPS,
and throttling that. Don't fight a dirty supply, bend it to your will and
make it work for you.

As for the bulb themselves, they're kind of noisy, and sure to drift
(especially over age), but as mentioned, they have been used from time to
time, and given their operating envelope, do about as well as you'd expect.

There were some varieties that were specially selected or formulated or
aged, if you wanted something smaller than a proper 0A3 or 0G3*. I'm
guessing this isn't important in this case, as your pile of junk-box bulbs
probably isn't the fancy kind.

*0G3 was the precision zener of its day, doing about 0.5% stability and
600nV/rtHz noise -- volt per volt, quieter than a TL431.

Tim

--
Seven Transistor Labs
Electrical Engineering Consultation
Website: http://seventransistorlabs.com

"Geoffrey S. Mendelson" <g...@mendelson.com> wrote in message
news:slrnmsdml...@cable.mendelson.com...

[Robert Baer]

All of these schemes mentioned are rather noisy; unless one uses a
large current thru those zeners,they will be very noisy (look like they
are oscillating).
If you can afford it,how about a regulator that is quiet from 1uA to
1mA (beyond spec current).
Available in 50V steps from 50V up to a few KV.

[Robert Baer]

Jeff Liebermann wrote:
> On Sun, 9 Aug 2015 04:49:03 +0000 (UTC), "Geoffrey S. Mendelson"
> <g...@mendelson.com> wrote:
>
>> What I do have is 50 NE2 bulbs with resitors. Could I use those?
>>
>> It would probably take 5 or 6 in series to do it, which compared to two
>> 5 cent zeners from eBay seems like a waste of money and circuit board real
>> estate, but I am looking to do something that does not require me to
>> order anything from anyone.
>
> The last time I tried to use a neon lamp as a voltage regulator, I
> managed to build to perfectly functional relaxation oscillator
> instead. Try googling for a GM power supply schematic:
> <https://www.google.com/search?tbm=isch&q=geiger+counter+power+supply+schematic>
> See any that use neon lamp regulators? That should be a clue.
>
> My antique CDV-900 counter uses a 900v regulator tube made by
> Victoreen.
> <http://www.logwell.com/tech/dhdwe/HV_woes.html>
> <http://www.logwell.com/products/Codatron_Corotron.html>
> There's a difference between these and neon lamps, but I don't recall
> the details. The designer of these replacements is someone that posts
> regularly to this newsgroup.
>
>
>
>
>
>

Yes; i just mentioned that the Codatron(R) is very quiet and
available in 50V steps from 50V.

[Phil Hobbs]

Why bother shielding the NE-2s? A bit of radiation or UVA will improve the turn-on performance, and is pretty unlikely to be noticed in operation.

Cheers

Phil Hobbs

[dca...@krl.org]

On Sunday, August 9, 2015 at 12:49:07 AM UTC-4, Geoffrey S. Mendelson wrote:

>
> What I do have is 50 NE2 bulbs with resitors. Could I use those?
>
> It would probably take 5 or 6 in series to do it, which compared to two
> 5 cent zeners from eBay seems like a waste of money and circuit board real
> estate, but I am looking to do something that does not require me to
> order anything from anyone.
>
> TIA
>
> Geoff
>
> --
> Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379

Many many years ago when I was in the Navy, the ship I was on had a radar repeater that used a NE-2 neon bulb as a voltage regulator. The neon bulb failed fairly often, maybe about every three months. Often enough that I could remember that it had failed before. So I bought a NE-2 from Radio Shack and used it instead of one from the Navy supply system. And it did not fail again while I was on that ship. Just pointing out that old stock may not be reliable.

I would try to come up with a circuit that used one neon bulb across part of a voltage divider to do the regulating. I think trying to use 5 or 6 in series would lead to very erratic behaviour.

Dan

[bitrex]

Indeed, I think some glow tubes were manufactured back in the day with a
small amount of radioactive material to encourage ionization in dark
environments.

[Jim Thompson]

On Sun, 9 Aug 2015 04:49:03 +0000 (UTC), "Geoffrey S. Mendelson"
<g...@mendelson.com> wrote:

Since you indicate they are "with resistors" (I presume built-in) they
won't act as regulators... the resistor drop will ruin the regulation.

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

[Jeff Liebermann]

I found a GE Glow Lamp Manual 2nd edition 1966 on my bookshelf. I was
waiting for neon lamps to make a comeback. Chapter 4 includes using
glow lamps for voltage regulation:
<http://www.introni.it/pdf/GE%20Glow%20Lamp%20Manual.pdf>
<http://vacuumtubes.biz/documents/Glow%20Lamp%20Specifications.pdf>
If you search through the catalog pages at the end for "radioactive",
you will find which lamps had something radioactive added to reduce
dark effect. I couldn't find any documents listing what radioactive
materials were added to neon lamps. If it was something like
Krypton-86 (10.8 years) or Tritium-3 (12.3 years), the radioactivity
is probably gone by now. Beware of old stock.

[M Philbrook]

In article <7357a189-7423-4048...@googlegroups.com>,
pcdh...@gmail.com says...

>
> Why bother shielding the NE-2s? A bit of radiation or UVA will improve the turn-on performance, and is pretty unlikely to be noticed in operation.
>
> Cheers
>
> Phil Hobbs

They make excellent lightning detectors :)

[piglet]

On 09/08/2015 17:45, Jeff Liebermann wrote:

> dark effect. I couldn't find any documents listing what radioactive
> materials were added to neon lamps. If it was something like
> Krypton-86 (10.8 years) or Tritium-3 (12.3 years), the radioactivity
> is probably gone by now. Beware of old stock.
>
>

Don't know about those gases but at least one model used an isotope of
nickel, it was loaded into a paint a dab of which was inside the glass
envelope.

piglet

[Spehro Pefhany]

On Sun, 09 Aug 2015 09:45:21 -0700, the renowned Jeff Liebermann
<je...@cruzio.com> wrote:

>On Sun, 9 Aug 2015 09:13:17 -0400, bitrex
><bit...@de.lete.earthlink.net> wrote:
>
>>On 8/9/2015 7:36 AM, Phil Hobbs wrote:
>>> Why bother shielding the NE-2s? A bit of radiation or UVA will improve the turn-on performance, and is pretty unlikely to be noticed in operation.
>>> Cheers
>>> Phil Hobbs
>
>>Indeed, I think some glow tubes were manufactured back in the day with a
>>small amount of radioactive material to encourage ionization in dark
>>environments.
>
>I found a GE Glow Lamp Manual 2nd edition 1966 on my bookshelf. I was
>waiting for neon lamps to make a comeback. Chapter 4 includes using
>glow lamps for voltage regulation:
><http://www.introni.it/pdf/GE%20Glow%20Lamp%20Manual.pdf>
><http://vacuumtubes.biz/documents/Glow%20Lamp%20Specifications.pdf>
>If you search through the catalog pages at the end for "radioactive",
>you will find which lamps had something radioactive added to reduce
>dark effect. I couldn't find any documents listing what radioactive
>materials were added to neon lamps. If it was something like
>Krypton-86 (10.8 years) or Tritium-3 (12.3 years), the radioactivity
>is probably gone by now. Beware of old stock.

The GE document specifically says that the "mild radioactive" additive
is added to the neon gas.

Neon John said (back in 2011) with reference to fl. starters and enon
lamps.

"A long time ago a touch of Thorium oxide was added, the purpose being
for the radioactivity to establish a uniform ionization environment
and thus stabilize the strike voltage. As the Cold War progressed and
the nation had Kr-85 running out its ears, that isotope was
substituted for the Thorium. Easier to inject a little gas than to
mix the thorium oxide in with the electrode material.

The same protocol goes for neon lamps. The only minor problem is that
Kr-85 has a 10.7 year half life and so if the equipment at hand is
very old, the starter or neon lamp may not be reliable."

--sp





--
Best regards,
Spehro Pefhany
Amazon link for AoE 3rd Edition: http://tinyurl.com/ntrpwu8
Microchip link for 2015 Masters in Phoenix: http://tinyurl.com/l7g2k48

[John S]

If struck directly? Sure. So does a tree or, hopefully, you.

[Jeff Liebermann]

Thanks. I recall the discussion but was too lazy to search for it.

Neon lamps probably use the same radioactive isotopes as a fluorescent
starter. Some possibles are listed in:
<http://www.irpa.net/irpa10/cdrom/00740.pdf>
Half-Life Emits
Kypton-85 10.8 years Beta
Promethium-147 2.6 Beta
Tritium H3 12.3 Beta
Thorium-232 14 billion years Alpha
I can see why they used Thorium. Promethium seems too short. Krypton
and Tritium are longer but I would still be worried about the
usability of "old stock" neon lamps.

[Jim Thompson]

On Sun, 09 Aug 2015 09:45:21 -0700, Jeff Liebermann <je...@cruzio.com>
wrote:

>On Sun, 9 Aug 2015 09:13:17 -0400, bitrex
><bit...@de.lete.earthlink.net> wrote:
>
>>On 8/9/2015 7:36 AM, Phil Hobbs wrote:
>>> Why bother shielding the NE-2s? A bit of radiation or UVA will improve the turn-on performance, and is pretty unlikely to be noticed in operation.
>>> Cheers
>>> Phil Hobbs
>
>>Indeed, I think some glow tubes were manufactured back in the day with a
>>small amount of radioactive material to encourage ionization in dark
>>environments.
>
>I found a GE Glow Lamp Manual 2nd edition 1966 on my bookshelf. I was
>waiting for neon lamps to make a comeback. Chapter 4 includes using
>glow lamps for voltage regulation:
><http://www.introni.it/pdf/GE%20Glow%20Lamp%20Manual.pdf>
><http://vacuumtubes.biz/documents/Glow%20Lamp%20Specifications.pdf>
>If you search through the catalog pages at the end for "radioactive",
>you will find which lamps had something radioactive added to reduce
>dark effect. I couldn't find any documents listing what radioactive
>materials were added to neon lamps. If it was something like
>Krypton-86 (10.8 years) or Tritium-3 (12.3 years), the radioactivity
>is probably gone by now. Beware of old stock.

Back around 1961, while a student at MIT, I had a bad experience...

I had a tube amplifier which used 0A2's as regulators.

I located the amplifier on a shelf in the attic (I had a remote
preamplifier... Germanium transistors, no less :-) and it was left on
all the time, no problems.

Summer of '61, decided to vacation back home in WV, so I shut off
amplifier power.

On my return, a month later, I flipped the power switch... KABOOM! A
number of electrolytic cans blew out their bottom seals...
over-voltage :-(

[Bill Beaty]

Some of the geiger counter kits from Electronics Goldmine use a chain of NE-2 bulbs as their HV DC regulator.

"NE-2 bulbs with resistors"

Cut off the resistors, just use a chain of neon lamps alone.

[jurb...@gmail.com]

>"Why bother shielding the NE-2s? A bit of radiation or UVA will improve the turn->on performance, and is pretty unlikely to be noticed in operation. "

Wouldn't that change the ionization somehow and thus the intrinsic voltage drop needed to regulate voltage ?

And I say just use one and use resistors like they did in the earlier solid state analog "pass transistor" type regulator controllers.

[jurb...@gmail.com]

>"I would try to come up with a circuit that used one neon bulb across part of a >voltage divider to do the regulating. I think trying to use 5 or 6 in series >would lead to very erratic behaviour.

> Dan "

Agreed, in fact I just posted something to that effect almost.

[Jeff Liebermann]

On Sun, 9 Aug 2015 15:25:27 -0700 (PDT), jurb...@gmail.com wrote:

>>"Why bother shielding the NE-2s? A bit of radiation or UVA will improve the turn->on performance, and is pretty unlikely to be noticed in operation. "

>Wouldn't that change the ionization somehow and thus the
>intrinsic voltage drop needed to regulate voltage ?

No. The radiation only lowers the threshold voltage by ionizing some
of the gas inside the bulb. It has the same effect as shining a light
on the NE-2 to produce the "dark effect". Once the lamp "fires", the
lamp is full of ionized gas, which keeps the neon lamp turned on
(hysteresis). Once "fired", the operating voltage remains constant
and is unaffected by the radiation. Therefore, no change in
regulation voltage.

>And I say just use one and use resistors like they did
>in the earlier solid state analog "pass transistor" type regulator
>controllers.

Supposedly, you can use the neon lamp threshold effect to build a
gamma ray radiation detector without the GM tube or PIN diode detector
(alpha and beta won't go through the thick NE-2 glass envelope):
<http://electronicdesign.com/test-amp-measurement/simple-geiger-detector-uses-neon-glow-lamp>
<http://electronicdesign.com/site-files/electronicdesign.com/files/archive/electronicdesign.com/files/29/1634/figure_01.gif>
Of course, there are those in this newsgroups who claim it doesn't
work:
<https://groups.google.com/forum/#!topic/sci.electronics.design/8SBFx8tEBe0>

If you don't like high voltage, there are also PIN diode and solar
cell radiation detectors:
<http://www.maximintegrated.com/en/app-notes/index.mvp/id/2236>
<http://www.carroll-ramsey.com/detect.htm>
<http://hackaday.com/2013/06/03/a-very-tiny-gamma-ray-detector/>
<https://www.sparkfun.com/products/9541>
Or, you can buy one ready to play for your Android or iThing:
<http://www.ebay.com/sch/i.html?_nkw=android+radiation+detector>
A friend bought one and we compared it to my CD-700 GM counter. It
worked and would detect my sources, but at far lower cpm (counts per
min). Actually, the sensitivity is about the same, but the capture
area of the PIN diode is much smaller than the GM tube.

[Jeff Liebermann]

On Sun, 9 Aug 2015 04:49:03 +0000 (UTC), "Geoffrey S. Mendelson"
<g...@mendelson.com> wrote:

(...)

Never mind using neon bulbs as regulators. Use zener diodes.

400V High Voltage Regulator. $7.50
<http://uraniumrocks.com/collections/cdv-700-parts-and-upgrades/products/400v-high-voltage-regulator-for-cdv-700-use-with-russian-gm-tubes>

[M Philbrook]

In article <lunfsa1bgrq05vl2f...@4ax.com>,
je...@cruzio.com says...

>
> On Sun, 9 Aug 2015 04:49:03 +0000 (UTC), "Geoffrey S. Mendelson"
> <g...@mendelson.com> wrote:
> (...)
>
> Never mind using neon bulbs as regulators. Use zener diodes.
>
> 400V High Voltage Regulator. $7.50
> <http://uraniumrocks.com/collections/cdv-700-parts-and-upgrades/products/400v-high-voltage-regulator-for-cdv-700-use-with-russian-gm-tubes>

I bet that website is on the watch list :)

Jamie

[Frank Miles]

On Sat, 08 Aug 2015 23:16:18 -0700, Jeff Liebermann wrote:

> On Sun, 9 Aug 2015 04:49:03 +0000 (UTC), "Geoffrey S. Mendelson"
> <g...@mendelson.com> wrote:
>
>>What I do have is 50 NE2 bulbs with resitors. Could I use those?
>>
>>It would probably take 5 or 6 in series to do it, which compared to two
>>5 cent zeners from eBay seems like a waste of money and circuit board
>>real estate, but I am looking to do something that does not require me
>>to order anything from anyone.
>
> The last time I tried to use a neon lamp as a voltage regulator, I
> managed to build to perfectly functional relaxation oscillator instead.
> Try googling for a GM power supply schematic:
> <https://www.google.com/search?tbm=isch&q=geiger+counter+power+supply
+schematic>
> See any that use neon lamp regulators? That should be a clue.
>
> My antique CDV-900 counter uses a 900v regulator tube made by Victoreen.
> <http://www.logwell.com/tech/dhdwe/HV_woes.html>
> <http://www.logwell.com/products/Codatron_Corotron.html>
> There's a difference between these and neon lamps, but I don't recall
> the details. The designer of these replacements is someone that posts
> regularly to this newsgroup.

Back in the day, Tektronix used neons as power indicators. They
subsequently banned them from this service as all too often their
negative dynamic resistance oscillated with the stray wiring
capacitance (as in Jeff L's example). This could get into other
parts of the 'scopes and cause real mischief.

[whit3rd]

On Saturday, August 8, 2015 at 9:49:07 PM UTC-7, Geoffrey S. Mendelson wrote:
> I am building an experimental radiation detector. Being an experiment, I

> want to avoid buying anything for it. Sort of a junkbox project...

> The geiger muler tubes I have require 400 volts. I could do it easily buy
> buying 200 volt zener diodes and put two in series.

The principle of a Geiger detector is that it stores VERY LITTLE energy, and
the HV supply isn't regulated, it takes a drastic drop every time a particle
is detected, Use a transformer-winding ratio and battery supply
at (nearly constant) voltage will give you a steady-enough HV source.

[Jeff Liebermann]

On Mon, 10 Aug 2015 00:16:34 +0000 (UTC), Frank Miles
<f...@u.washington.edu> wrote:

>Back in the day, Tektronix used neons as power indicators. They
>subsequently banned them from this service as all too often their
>negative dynamic resistance oscillated with the stray wiring
>capacitance (as in Jeff L's example). This could get into other
>parts of the 'scopes and cause real mischief.

Yep. I have two Tektronix T922 scopes. They're the one's on the top
of the pile:
<http://802.11junk.com/jeffl/crud/scopes-to-be-fixed.jpg>
<http://www.logwell.com/tech/oscilloscopes/T922R_service_notes.html>
"T922Rs below serial number B011950 have a neon power
indicator pilot lamp, and those with serial number B011950
and up have an LED power indicator."

Both of mine came with the a neon indicator, which could sometimes be
visually seen oscillating at about 2 Hz. There is a 1uf across the
neon lamp and 100K resistor in series. It's powered by +100v
unregulated, which should be high enough to prevent oscillation, but
doesn't. Per a suggestion on the Yahoo TekScopes group, I replaced it
with an LED. The 2 Hz glitches on the slow sweeps went away.

[Jeff Liebermann]

On Sun, 9 Aug 2015 19:48:13 -0400, M Philbrook
<jamie_...@charter.net> wrote:

>In article <lunfsa1bgrq05vl2f...@4ax.com>,
>je...@cruzio.com says...

>400V High Voltage Regulator. $7.50
><http://uraniumrocks.com/collections/cdv-700-parts-and-upgrades/products/400v-high-voltage-regulator-for-cdv-700-use-with-russian-gm-tubes>

>I bet that website is on the watch list :)
>Jamie

I don't have a watch list. I keep a collection of bookmarks on
CDV-700 repairs because I was receiving about one related repair
question per month. The short story is that I own exactly one CDV-700
6B Lionel GM Survey Meter:
<http://www.orau.org/ptp/collection/civildefense/cdv700.htm>
Thanks to my inept initial repairs, I had some difficulties getting it
to work reliably. I compounded my mistake by allowing the two D cell
batteries to leak all over the inside. After a few assorted questions
and answers in various Yahoo groups, I managed to fix it. Since then,
I've repaired 5 similar meters, mostly by careful cleaning the
phenolic PCB. Two had sick GV3A Corotron regulator tubes, which I
replaced with a string of zener diodes totaling 900v. I also replace
the nearby high voltage disc capacitors which ocassionally arc over
and short.

Would you believe only 2 transistors?
<http://www.dvq.com/geiger/cdv700_6.jpg>

[Robert Baer]

That was one of the tricks that Victoreen did for their Corotron(TM)
high voltage regulators.

[Robert Baer]

Perhaps you are confusing the striking voltage with the on/regulating
voltage (different ionization levels,look in Handbook of Chemistry and
Physics).

[Robert Baer]

Jeff Liebermann wrote:
> On Sun, 9 Aug 2015 04:49:03 +0000 (UTC), "Geoffrey S. Mendelson"
> <g...@mendelson.com> wrote:
> (...)
>
> Never mind using neon bulbs as regulators. Use zener diodes.
>
> 400V High Voltage Regulator. $7.50
> <http://uraniumrocks.com/collections/cdv-700-parts-and-upgrades/products/400v-high-voltage-regulator-for-cdv-700-use-with-russian-gm-tubes>
>

Their solid-state HV regulator is a lot noisier than the Codatron(R),
roughly as bad as the regulators that Titan Industries used to make.

[jurb...@gmail.com]

>" Perhaps you are confusing the striking voltage with the on/regulating
>voltage (different ionization levels,look in Handbook of Chemistry and
>Physics). "

Something I never had cause to look into, but if that voltage really is that stable I guess that is sort of the tube equivalent of a Zener diode, bidirectional in fact.