[TenTec] 253 Keying Loop - Intermittent

[Rick Williams]

I'm not sure if others may have encountered this BUT over a period of many
months I've been having an intermittent problem with my keying loop.
Equipment in the loop consists of:

           Hercules II
           Orion (565)
           SteppIR Antenna Tune Circuit (home brew)
           LP-100 RF Wattmeter
           253 Automatic Antenna Coupler

After some frustrating sleuthing, I tracked the problem down to the 253.  It
seemed that if I lost the keying loop all I had to do was wiggle the Exciter
IN/Out cables on the 253 and I was back in business.

Before anyone asks - YES I replaced the cables -- more than once.

Since the problem occurred even while the 253 was in Bypass it suggested the
Exciter In/Out jacks or, even more remote, relay K6 was the likely problem.

It was a fairly painless job to partially extract the appropriate board
(81486) and resolder the jacks and relay.  In addition I built-up the centre
conductor on the RCA jacks. (It seems likely that a previous owner may have
forced an over-size or over-soldered RCA plug into one or both of the
jacks.)

It's all back together and working well.  (If anyone else has encountered
this frustrating problem they may want to look at a summary of this simple
repair on my website.)

73, 

Rick 
VE7TK

Website:  http://www3.telus.net/ve7tk