Tom -
OK, almost certainly a bad crystal. If you have another crystal around
20 Mhz or so you could try it, but I'd be willing to bet you would see a
negative voltage with the new one.
73, Garey - K4OAH
Glen Allen, VA
Drake 2-B, 4-B, C-Line& TR-4/C Service Supplement CDs
<www.k4oah.com>
Tom McDaris wrote:
Garey:
I attached the neg of the volt meter to the chassis and the pos to
the TP behind the S meter and saw -.35V on 10mtrs, -.54 on 15mtrs and
+3.73 on 40mtrs. I also see some wattage, maybe half a watt on 40. I
don't have a portable receiver to take down there on the bench. Tom
----- Original Message ----- From: "Garey Barrell" <k4...@mindspring.com>
To: "Drakelist" <drakelist@zerobeat.net>
Sent: Monday, March 22, 2010 9:49 AM
Subject: Re: [Drakelist] No output on 40 meters of TR4-C
Tom -
Invalid test..... There is NO crystal on 80 or 20M, therefore no
voltage at the TP. You must compare with the 15 and 10M positions.
There may be an alignment or other problem, but first we have to know
if the oscillator is working on 40M the same way it does on 15 and 10M.
73, Garey - K4OAH
Glen Allen, VA
Drake 2-B, 4-B, C-Line& TR-4/C Service Supplement CDs
<www.k4oah.com>
Tom McDaris wrote:
Garey:
I tried the volt meter at TP to crystal socket and got nothing
on the 40 crystal socket. I then tried it on 80 and got the same.
80 works fine so no cigar here. I cleaned the 40 mtr crystal pins
and socket. On 40, when you put it on CAL and turn the RF tune the
tone gets louder as you go clockwise and is loudest at the stop. It
is as if it could go higher if the stop wasn't there. Could this
just be an alignment issue? Thanks for your comments. Tom AB8BW
----- Original Message ----- From: "Garey Barrell"
<k4...@mindspring.com>
To: <drakelist@zerobeat.net>
Sent: Sunday, March 21, 2010 11:17 PM
Subject: Re: [Drakelist] No output on 40 meters of TR4-C
Tom -
Sounds like you may have a bad crystal. They DO go bad.
Easiest is to connect a DMM or VTVM to the test point on top of the
chassis just behind the S-Meter. You should measure a volt or so
of negative voltage, and it should be about the same on the 40, 15
and 10M BAND switch positions.
You could try listening on a separate receiver that covers 21.5 MHZ
if available. You might need to run a wire from the receiver
antenna lead near the tube V1, right behind the S-Meter.
73, Garey - K4OAH
Glen Allen, VA
Drake 2-B, 4-B, C-Line& TR-4/C Service Supplement CDs
<www.k4oah.com>
Tom McDaris wrote:
I have a TR4-C with good output everywhere but 40 meters. On 40 I
get nothing. ZIP! I get idle current but when you try the
tune-up, nothing happens. I have cleaned the band switch with
alcohol & Q-tip. I cleaned the crystal pins with alcohol. I tried
the alignment procedure in the TR-4 manual. Nothing. Any
suggestions would be appreciated. 73 AB8BW
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