[GreenKeys] Radio valve/tube CG 502A

[E. Groenenberg]

Ah, the speed of internet, just after I posted my reply this came in ....

I'm going to replace a 2050 in the stepper circuit for a 502A and see
if it wild hold out. In that case I have a nice set of spars for my
Jukebox. (A Seeburg model 101 btw.)

Ed

On Wed, March 22, 2017 19:30, Bruce Gentry wrote:
> These are electrically equal to the 2050 thyratron, but in metal shells.
> At Midstate Elevator we bought a couple cases of those in the early 80s
> for use in older Otis controllers. They were  cheaper than the 2050, and
> seemed to be more stable. In some controller circuits, the heater
> voltage was carefully regulated so the firing voltage would be constant.
> There are solid state plug in replacements for them today, but they
> false fire too often and RF in the machine room causes lots of troubles.
> Some things are still best done with tubes. There are few techie nerd
> delights like a large relay logic elevator group control system in
> operation, but the number of them still in service is decreasing fast
> today.
>
>       Bruce Gentry
>
> On 3/22/17 1:43 PM, Jones, Douglas W wrote:
>> On Mar 22, 2017, at 11:48 AM, E. Groenenberg wrote:
>>
>>> I have found 10 pieces of radio valves/tubes, metal can with
>>> the print 'JAN CG 502A' on them
>> Google finds this document title, published Aug. 5, 1955 and currently
>> listed as obsolete with no superseding document:
>>
>> MIL-E-1/909 › Electron Tube, Transmitting, Thyratron, Tetrode, Gas
>> JAN-502A
>>
>> Type 502A tubes appear to be widely available at $5 and up.  I didn't
>> find a spec sheet, though.
>> ______________________________________________________________
>> GreenKeys mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/greenkeys
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:GreenKeys at mailman.qth.net
>>
>> 2002-to-present greenkeys archive:
>> http://mailman.qth.net/pipermail/greenkeys/
>> 1998-to-2001 greenkeys archive:
>> http://mailman.qth.net/archive/greenkeys/greenkeys.html
>> Randy Guttery's 2001-to-2009 GreenKeys Search Tool:
>> http://comcents.com/tty/greenkeyssearch.html
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to ka2ivy at verizon.net
>>
>
> ______________________________________________________________
> GreenKeys mailing list
> Home: http://mailman.qth.net/mailman/listinfo/greenkeys
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:GreenKeys at mailman.qth.net
>
> 2002-to-present greenkeys archive:
> http://mailman.qth.net/pipermail/greenkeys/
> 1998-to-2001 greenkeys archive:
> http://mailman.qth.net/archive/greenkeys/greenkeys.html
> Randy Guttery's 2001-to-2009 GreenKeys Search Tool:
> http://comcents.com/tty/greenkeyssearch.html
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to ed at groenenberg.net
>