----- Original Message -----
From: "Richard Knoppow" <[email protected]>
To: "Drakelist" <[email protected]>
Sent: Friday, May 13, 2011 1:04 AM
Subject: [Drakelist] Some TR-4 Questions
After some work, the 10 meter problem is cured. I
cleaned the band switch thoroughly and reseated the
crystals. I also worked all the screws on sockets and
terminal boards. I now have clean operation on all three of
the 10 meter positions. I checked sensitivity using an -hp-
606-A signal generator and its correct, that is, 30uv
produces about S-9.
Other problems remain but I am about to do a complete
alignment and it may take care of some of them.
The TR-4 book requires the use of a loading circuit
composed of a resistor and capacitor. One service note
included in Garey's disc suggests its not necessary but I
think that is for the T-4 series not the TR-4. Anyway I will
make one up and use it. If the transformers being tuned are
overcoupled the loading circuit is necessary to avoid
interaction of the two sides.
At this point I still have:
Low power out, about 70 watts on 80 meters and about 60
watts on 40 and 20. Substituting other tubes brings it up a
little but not much. The second set of tubes may not be
good.
Regeneration on the 40 meter band in receive. This may
be cured by alignment. I may be getting just a little on
other bands but its quite noticable on 40.
Bouncing meters. I will be looking at the meter assembly
to see if anything can be done about this. Its also possible
that although the meters seem to indicate correctly that
something may be wrong with the resistors they are connected
to.
I am posting in detail for the possible benefit of
others who may encounter the same problems.
--
Richard Knoppow
Los Angeles
WB6KBL
[email protected]
_______________________________________________
Drakelist mailing list
[email protected]
http://mailman.zerobeat.net/mailman/listinfo/drakelist
