[ARC5] 1626 tubes

[WA5CAB at cs.com]

Brian,

I don't think that there is anything particularly unusual about the 1626 but 
although it's characteristics may be similar to those of the 6J5, it is listed 
in all of the RCA Transmitting Tube, not Receiving Tube, Handbooks as an RF 
Amplifier and Oscillator.

The 12J5GT is used as the MCW Oscillator in all of the Command Set 
modulators.  There is no audio voltage amplifier in any of them.  The 1625 grid(s) are 
driven directly by the carbon microphone transformer, as was common in most of 
the low-powered transmitters (there was a thread on that subject on MILSURPLUS 
a while back).

Someone else on one of these lists offered a bunch of 1626's last year.  
Don't recall what he was asking for them and don't know what AES's current price 
is but I charge a flat $5.00 each for most receiving tubes (and would despite 
the previous paragraph include 1626's in that category) except rectifiers, or 
$4.00 for around five or more mix and match.  The low-end tube business is a 
lot of work for little return so I've never pursued it.  But on the other hand, 
I've never declined to send someone a tube or two when they asked for them.  
So if you need some 1626's just let me know how many.  :-)

In a message dated 8/20/2006 12:54:16 AM Central Daylight Time, 
brianclarke01 at optusnet.com.au writes: 
> I wonder if the 1626 is an unusual tube?
> The 1626 is approximately a 12J5 with JAN numbering and bulbous garb.
> Usually a JAN numbered tube for 12 V heater operation is a 12 V version of a
> 6 V heater tube, eg, 1625 transmogrified from an 807.
> However, the 6J5 is, AFAIR, a 6SJ7 with all the grids strapped together.
> Whereas, when I look into a 1626, I don't see multiple grids.
> 
> Now, to reduce distortion, tube manufacturers try to get multiple grids
> aligned
> in the shadow of the control grid - but, I rather gather this was not the
> case with
> the 6SJ7, which was designed for maximum amplification. So, the 1626 may
> not only be more rugged, but also have lower distortion than the 6J5/12J5.
> 
> Can anyone clarify?
> 
> And, Robert, the only other application I can recall for the 1626 was as an
> audio
> voltage amplifier in the ARC-5 modulator. If you have hundreds, I wouldn't
> mind
> just a few for getting some of my Command transmitters operational.

Robert & Susan Downs - Houston
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