"Ernie" wrote in message
m...
I've stared at the underside and tried to follow wires
buried deep in the tightly-bound wire bundles till my eyes
are about to pop out. Can anyone direct me where to find
resistor "R-63" which is 22 meg ohm? My receiver is very
very weak, almost sounds dead although I can hear signals
at a very low level and am thinking my AVC may be the
culprit.


First of all I highly recommend you get the DVD for the
TR-4 from Garrey
www.k4oah.com This has a lot of information not in the
handbooks including photographs of the wiring. It also has
the handbooks and schematics for all variations.
I doubt very much that its the AVC. But check the RF
gain control to make sure its not turned way down, this is
the little lever under the receiver volume control.
Another thing to check is the protection lamp. This is
a pilot lamp in series with the antenna to prevent burn out
from strong signals, remember the TR-4 was intended for
mobile use. This is a small bi-post lamp in the compartment
with the final tubes. If its open or if the socket has
gotten corroded the antenna is effectively disconnected from
the receiver. If the thing is dead on all bands this is a
possibility.
There is also a switch on the left side near the back
for Receiver or Transceiver. It can also become dirty. Just
working it a few times will usually fix it.
Beyond that clean the band switches and make sure the
tubes are tight in their sockets.
Tracing wiring is difficult because of the very compact
construction. Check these obvious things first.



--

--
Richard Knoppow
Los Angeles
WB6KBL

Thanks Richard. Yes I checked all the obvious stuff first...RF gain control,
persnickety "RCV/TRCV" slide switch on the side, antenna bulb fuse etc. Also
removed and checked the trimmer and coils of the IFs. I'm now focused on
a -0.25 VDC bias measurement on the 2 IF tubes instead of the -0.10 VDC
shown on the voltage chart.

Will update as progress is made.

"Ernie" wrote in message
...
Thanks Richard. Yes I checked all the obvious stuff
first...RF gain control, persnickety "RCV/TRCV" slide
switch on the side, antenna bulb fuse etc. Also removed
and checked the trimmer and coils of the IFs. I'm now
focused on a -0.25 VDC bias measurement on the 2 IF tubes
instead of the -0.10 VDC shown on the voltage chart.

Will update as progress is made.

Ernie, I think you may get more help by joining one of
the Drake mailing lists. There is one at:

http://groups.yahoo.com/group/DrakeRadio/join

and another at:

http://mailman.zerobeat.net/mailman/listinfo/drakelist

Nearly the same people on both. In particular Garrey
Barrell is quite expert and may know what has happened
immediately.


--
Richard Knoppow
Los Angeles
WB6KBL