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bitrex bitrex is offline
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Default A solid state replacement for the lowly 2D21 Thyratrontube...(sorry for the On-Topic post!)

On 4/22/2021 4:04 AM, wrote:
bitrex wrote in
:

On 4/21/2021 11:29 PM,

wrote:
bitrex wrote in
:

On 4/21/2021 10:42 PM, Fox's Mercantile wrote:
On 4/21/21 8:31 PM,

wrote:
110 VAC went away at the beginning of the 20th century.* By
1950 120 Volts was the standard.* The MONIKER remained, but
the voltage has been 120 VAC for a VERY long time.

We go through this over and over again on the antique radio
news group.
110, 117, 120 = 120 vac



I'm hearing that DLUNU would like to take responsibility for
this project and I think he's the best qualified based on his
rebuttal. I mean it's in his name. "NumeroUno"


In case you missed it, he was backing me up.


I would hope so! You're team lead, now


No... According to the LarkinPunk, I am a mere "technician" who
"hates the magic" of engineers.


Sounds like you have something to prove. Sometimes when I'm helping the
little ol' lady in the library do her taxes some kid shows up with
something to prove too and is like "No dummy you're doing that all
wrong" and then I say "Okay.." and hand the job off directly to him, let
him spend the next two hours with her while I go about my day. I'm not
going to fight him on it he is the white-knight expert who has appeared
in our time of most need. And it makes Ethel very happy!

But that's interesting about the line voltage it seems to be a common
misconception and 1954 was a long time before I was born. In any case my
thoughts on the 2D21-dying issue have changed it's not hydrogen-filled
it's probably primarily xenon. Hydrogen-filled thyratrons are more
temperature-sensitive to both the temperature of the heater and
temperature of the glass if they're too hot all the hydrogen tries to
run away or react with the hot cathode. Obviously xenon won't react with
the internal elements or the getter but it can still be absorbed by the
glass or escape where the pins come in.

So I still think the reason they end up malfunctioning in service is
that the gas is escaping or being absorbed by the glass and reducing the
operating temperature of the cathode may extend their life.