[Hammarlund] hq-180a

Fri, 15 Aug 2003 20:54:17 -0400

What do you consider "normal" ?
All tube radios drift with warm-up. The greater the temperature differential
between room temperature, and the temp of the set after, say, an hour of
running, the more likely the drift. Another factor is the ability of the
metal mass to "sink" the heat. A more heavily built receiver, such as an
SP-600 will be less affected by this.
I have an HQ-180 that has been in operation on my shop bench for a few
years. It is very consistent in its drift. Always lower, and for about an
hour. I don't think that it is more than a few Khz, however. I consider this
to be normal for this model.
There are a couple of other, maintenance items that can contribute also.
These sets use miniature tubes, which are notorious for intermittent pin
contacts. If these connections are not clean and "tight", this will
contribute to drift. I had this issue with my HQ-180 when I first got it. It
took more than one session with the contact cleaner before this problem was
solved.
Chuck N1LNH
----- Original Message ----- 
From: "DAN COTSIRILOS" <[email protected]>
To: <[email protected]>
Sent: Friday, August 15, 2003 11:05 AM
Subject: [Hammarlund] hq-180a


Hello

    I have a hq-180a that I think drifts a little more than normal. I
changed the 6C4 tube with a new one and the results are still the same. What
could cause the drift? always goes lower.  Dan


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