[Drake] TR-4 troubleshooting

[Al Parker]

Hi Richard,
    Just a quick late-nite thought or 2.  If youhadn't mentioned the 40m 
being dead on both SB's, I'd say it sounded like one section of the filter 
was bad.  Is it an early TR-4 with a "soupcan" filter, both secns inside a 
single can?  If so, that's probably the main trouble.  TR-3's had that and 
they're notable for the problem.  Later TR-4's had 2 separate filters with 
an external switch.   (switch was intermal to the soupcans)  So, if you have 
separate filters, I'd first suspect the bandswitch and the filter switch 
oughta have a judicious application of DeOxit.  Maybe that'd clear things 
up.
    That's a quick few thoughts wihile I'm on the way to the sack.  Let us 
know how things look.  YMMV
73,
Al, W8UT
New Bern, NC
www.boatanchors.org
www.hammarlund.info

"there is nothing -absolutely nothing- half as much worth doing as simply 
messing about in boats."
   Ratty, to Mole


----- Original Message ----- 
From: "Richard Peterson" <wb5nen at hotmail.com>
To: <drake at mailman.qth.net>
Sent: Wednesday, September 03, 2008 9:20 PM
Subject: [Drake] TR-4 troubleshooting



Any good TR-4 troubleshooters on line? My good old TR-4 has gotten "testy" 
again, this time it works on some modes and not others. For example, on 80 
meters, it works fine on USB with good output, but has no output on lower 
sideband. On 40 meters, both modes are dead: It will receive, but 
calibration is way off. On 20 meters, USB is good and LSB has no output; on 
15 meters, USB is dead and LSB is OK. You get the picture.

There is no "mixing" with the xtal oscillator in this design on both 80 and 
20. Therefore, 9 MHZ IF plus 5 MHX PTO gives you 14 MHZ, and on 80, it uses 
the 9MHZ IF minus the 5 MHZ PTO to five you 4 MHZ. Too, the sideband filters 
get switched back and forth, I believe.

Regardless, this is very screwy. As I said, any good 'shooters out there?

Richard
WB5NEN

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