[GreenKeys] Radio valve/tube CG 502A

[E. Groenenberg]

First of all, thanks for the responses.

I got these some 15 years ago being part of a bunch of tubes I acquired
for jukebox amplifiers. So a thyratron sounds like it could have been
used to drive relays like the 2D21 (of which I have still about one
hundred of them, those will last a lifetime ;)

The 2D21 was is/was used in Seeburg jukeboxes of the 1950's era, they also
used the 2050 (large glass envelope) to control the stepper relays.
It looks like the GC502A is a model which fits in between the 2D21 and the
2050, and is (at least) pin compatible with the 2050

Thanks,

Ed

On Wed, March 22, 2017 19:16, John Poulton wrote:
> Ed,
>
> You got me curious about what the heck the 502 might have been used for.
> It turns out to be fairly similar to the 7-pin miniature 2D21, a VERY
> common tube, often seen at hamfests; I've seen literally 100's of them in
> under-the-table boxes over the years.   Both the 502 and the 2D21 can deal
> with 1300PIV, both are tetrodes.  The current rating for the 502 is about
> twice that of the much smaller 2D21, but in other ways they're quite
> similar.
>
> The 2D21 was apparently used all over the place to drive relays and
> solenoids.  Evidently 2D21's and other small thyratrons were used in early
> "pulse and digital" circuits as pulse generators and timing circuits, and
> to trigger flash tubes.
>
> The 502 was almost certainly used for the same kinds of purposes.  There's
> a ton of information on the web about these things.. you just have to dig
> a
> bit.
>
> 73, John
>
>
>
> On Wed, Mar 22, 2017 at 1:41 PM, John Poulton <jp at cs.unc.edu> wrote:
>
>> Thyratrons are such special-purpose functions that I doubt you're going
>> to
>> find a "normal" sub.  I suspect RCA (or whomever) designed this thing
>> for
>> some special purpose, probably military, and there never was a sub.
>> There's a GL-507 that's a direct replacement, but it sounds like the
>> same
>> tube from a different vendor.
>>
>> The National Valve Museum says it was used as a "relay" or as a
>> grid-controlled rectifier.  It's good for 1A peak, so in the same ball
>> park
>> as small 5Y3-ish rectifiers.  See:
>>
>> http://www.r-type.org/exhib/aas0038.htm
>>
>> Don't know what the heck you're going to do with 10 of them, but.. there
>> you go!
>>
>> 73, John
>>
>>
>>
>>
>>
>> On Wed, Mar 22, 2017 at 1:13 PM, E. Groenenberg <ed at groenenberg.net>
>> wrote:
>>
>>> Hi.
>>>
>>> Yes it is, but searching google did not turn up any usable hits for me.
>>> I woultd like to know what the commercial equivalent tube is, f.e.
>>> an 6SK7 or 6SN7 or something like that.
>>>
>>> Ed
>>> --
>>> Ik email, dus ik besta.
>>> BTC : 1Lk6141nvDKPxtCa5erfFyovsoJN2LKqNJ
>>>
>>>
>>> On Wed, March 22, 2017 17:57, John Poulton wrote:
>>> > It's a standard black metal octal tube, right?  Various sources on
>>> the
>>> web
>>> > say that it's a thyratron tetrode.  Heaven knows what it was used
>>> for!
>>> > Thyratrons are sort of the hollow-state equivalent of an SCR, FWIW.
>>> >
>>> > 73, John K4OZY
>>> >
>>> > On Wed, Mar 22, 2017 at 12:48 PM, E. Groenenberg <ed at groenenberg.net>
>>> > wrote:
>>> >
>>> >> Hello All.
>>> >>
>>> >> A long shot, but there is a chance someone will know.
>>> >>
>>> >> I have found 10 pieces of radio valves/tubes, metal can with
>>> >> the print 'JAN CG 502A' on them, and the white cardboard boxes
>>> >> have a bunch of numbers etc. Must be Joint Army/Navy, but I have
>>> >> no idea what the more common equivalent type number would be.
>>> >> The are made by G.E.
>>> >>
>>> >> Anybody have an idea which type of tube it is?
>>> >>
>>> >> Thanks,
>>> >>
>>> >> Ed
>>> >> --
>>> >> Ik email, dus ik besta.
>>> >> BTC : 1Lk6141nvDKPxtCa5erfFyovsoJN2LKqNJ
>>> >>
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>>
>