[Milsurplus] Anyone Else Run an ARC-2?

[C.Whitaker]

de WB2CPN
You're right, 1 KHz was not that much, and a CW station
that had a unique chirp was easier to copy.
It's difficult to locate the culprit component because there
are so many suspects in that box.
When you drift, a good operator at the other end would
stay tuned to you.
73  Clete
++++++++++++++++++++++++++++++++++++++++++++

On 8/18/2013 9:58 AM, Bill Carns wrote:
> Not knowing the exact performance of an ARC-2 PTO during the transmit heat
> cycle, here is a suggestion.
>
> With the cover on (the way you have been using the rig) document as
> carefully as you can the drift vs. time while in transmit.  If nothing else
> just make  a gross "1 kHz in X seconds" measurement.
>
> Then, take the cover off and put a small fan on the PTO so that it sees room
> temp air during the transmit key cycle and measure it again.
>
> This will tell you where the culprit is and I suspect that it is drifting
> due to temperature in the box.
>
> 1 kHx sounds a bit excessive but you need to remember that this was 1945 and
> the AM receiver bandwidths were measured in 10s of kHz and a 1 kHz drift was
> not that noticeable.
>
> You may have lost a temp compensating cap in the PYO though. We see that all
> too regularly now.  They are getting old.  --  like me.
>
>
> Bill Carns, N7OTQ
> K0CXX, Trustee MRCCC
> President Collins Collectors Association
> Editor, Signal Magazine
> Founding Member # AC94-0009
> 512 618 2762 (Cell + VM)
> 512 847 7010 (Home + Fax)
>
>
>
>
> -----Original Message-----
> From: milsurplus-bounces at mailman.qth.net
> [mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of David Stinson
> Sent: Sunday, August 18, 2013 8:38 AM
> To: mrca at mailman.qth.net; milsurplus at mailman.qth.net; ARC-5 List
> Subject: [Milsurplus] Anyone Else Run an ARC-2?
>
> Has anyone else put an AN/ARC-2 on the air?
>
> On key-down, the PTO drifts about a KC.
> Before I take the cover off this gorilla of a radio and wrestle it to the
> ground, was wondering if this is common to the ARC-2 or if I need to look
> for a bad cap on the 250 VDC buss dragging it down on PTT.
>
> 73 DE Dave AB5S
>
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