A matched pair of what now?

Feb 27, 2011 18 Replies

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What exactly would one use a "matched pair" of neon discharge tubes for? And how would one match them?



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What would one use a "matched pair" of neon discharge tubes for, exactly? And how would one match them?

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Around 1960 I used neon tubes as "zenerdiodes" for 60-80 volt. Matching them on voltage for example, at the same series resistor.

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Firstly, they would have to be stable...meaning a small radioactive additive as well as long term burnin before testing.

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Since this type of tube is designed for intermittent high current discharges I don't see how that's possible...

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When I was a kid, there was a TV quiz show for high school students called "Reach For The Top." At my school we had a practice setup that used neon bulbs to indicate who hit his buzzer first.

Matching the threshold voltages would make that more nearly fair.

Cheers

Phil Hobbs

Dr Philip C D Hobbs Principal ElectroOptical Innovations 55 Orchard Rd Briarcliff Manor NY 10510 845-480-2058 email: hobbs (atsign) electrooptical (period) net http://electrooptical.net

"Bitrex"

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** The tubes are the same make, model, age and condition - ie " tested 100% excellent".

They look the same, they are a "pigeon pair".

So they match * each other *.

F****it.

.... Phil

"Bitrex"

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** The tubes are the same make, model, age and condition - ie " tested 100% excellent".

They look the same, they are a "pigeon pair".

So they match * each other *.

F****it.

.... Phil

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Shunt voltage regulators?

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These tubes appear to be more like thyratrons, where you get a discharge when the control electrodes see the proper combination of voltages. I'm curious if the type of tube testing equipment used by eBay sellers has the capability to electrically match, or even properly test, such tubes.

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Aside from matching the physical appearance, are there tube testers that are able to test the electrical characteristics of this type of cold cathode thyratron? I am genuinely curious.

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Neon would be an odd fill gas for thyratrons, I think--iirc it's usually hydrogen.

Cheers

Phil Hobbs

Dr Philip C D Hobbs Principal ElectroOptical Innovations 55 Orchard Rd Briarcliff Manor NY 10510 845-480-2058 email: hobbs (atsign) electrooptical (period) net http://electrooptical.net

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It's a weird tube, I guess it's designed as a strobe tube but the data sheet says it can also be used as a switching tube as well; from the pictures I've seen online of it in operation the color of the discharge definitely looks like neon. It has two control electrodes, kind of like a thyratron also. I've wanted to get my hands on one for a while now, but the prices on eBay are usually absurd.

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Not necessarily!

"Robert is not smarter than the average Bear"

** " It ain't necessarily so

It ain't necessarily so

The things that you're liable

To read in the Bible,

It ain't necessarily so ....... "

.... Phil

It looks like the sort of tube that was fitted to the early General Radio Stroboflash units. They had a neon red light, rather than the later xeon flash tubes white light. The trigger electrode allows external and accurate timing of the discharge point. You can find the manual for the GR Stroboflash on the web, where the schematic will reveal all.

The light output was modest in comparison to xeon, but we are talking about 1930's technology...

Regards,

Chris

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Those tubes were used as the flash lamps in early General Radio Strobotacs. Matching them means different things depending on the application - equal light output, equal breakover voltage, equal discharge voltage, etc.

73, Dr. Barry L. Ornitz WA4VZQ

=20

Just looking at the photo they appear to be rather ordinary 1D21 thyratrons. Pair matching has already been described. Only a little bit overpriced (2-3 X).

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for?

tested

Not all that difficult. But such a test set never was a mass market device (the tubes were industrial use primarily).

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