[CQ-Contest] If you don't have a TS-950S/D/X, don't read this

Tom HammondNØSS n0ss at earthlink.net
Thu Nov 15 23:00:41 EST 2001

Hi guys:

If you have a TS-950S/SD/SDX, please drop me a line DIRECTLY to my e-mail 
address, NOT via the reflector.

I've turned up a problem in my '950SD, and it may be something that many of 
us 950x owners may have and not know it (yet).

I dropped a note to Bob, K6XX, and his TS-950S has the problem as well.

Not to keep you in the dark, the problem is as follows:

   I was working a strong CW station on 20M. Had turned AGC off in
   order to obtain a 'cleaner' signal from him, and was
   controlling volume with the RG Gain as I've done for decades.

   Things were going just fine, until... his signal took a
   propagational peak and as if something in the front end (RF
   Gain) had gone into saturation, in an instant the RF gain went
   to MAX (RF Gain CONTROL still set to about 10 o'clock) and
   cranking on the RF Gain control itself had NO EFFECT
   whatsoever!!! Darn near blew the top of my head off.

   After several seconds of messing with controls, I found that I
   could momentarily switch the AGC back on (any mode but OFF) and
   then back to AGC OFF and regain control of the RG Gain control.
   Furthermore, I was able to re-create this problem, on the
   strong station ONLY, by manually cranking up the RG Gain a bit
   past a normal listening level, at which point it'd again
   avalanche and would no longer be controllable via the RF Gain
   control itself.

   I was not able to force this problem on ANY other signal on the
   20M band lost night, but then again none of the other signals
   that I heard during my testing were nearly as strong as the
   fellow I was working when the problem first occurred.

   This is certainly a problem that's gonna have to be FIXED...
   and soon.

   I have already corresponded with Bob Wolbert (K6XX) who wrote
   the TS-950 QSK CW Waveform Mod (and for which I made a PC
   board) about this problem and he says that his TS-950S does the
   same damned thing!!!

   Here is a snippet of Bob's reply comments:

     Yes, My TS950S (not D) has an unusable RF gain control.

     Want to duplicate the problem? Put the rig in AM mode.
     Completely unusable. Overshoot one way then the other.
     Its like the control is made of rubber!

I've not tried it on AM yet... suffice it to say that it's bad enough on CW.

I wonder if any of you can reproduce the problem in your rig as well.

If you choose to respond, PLEASE do so off-reflector. And at the very 
least, provide your e-mail address, call, TS-950 model (S/SD/SDX) and 
whether (or not) you can recreate the problem I'm seeing here. Any other 
comments are, of course, most welcome, but I'd really like to gather some 
info, so I'll have a bit of 'ammo' when I go to Kenwood. If it turns out 
that many of us can recreate the problem, them maybe we can also share in 
the solution.

By the way, if you use your 950 on CW, drop by Bob's web site:


and take a look at his CW QSK waveform mod, AND his AUX KEY input mod. If 
you are interested in performing the mod, PC boards are available from me. 
I have also written a set of step-by-step DOCs (in PDF) for performing the 
mods. I'm hoping Bob can put them up on his web site along with his mods, 
but until that happens, I do have them available here. Just ask. But please 
DO NOT ask unless you're really interested, the file is about 900kB in size 
and it takes a while (maybe even a couple of 'whiles') to send out.

73 and thanks for your time - Tom Hammond   N0SS

73 - Tom Hammond N0SS

CQ-Contest on WWW: http://lists.contesting.com/_cq-contest/
Administrative requests: cq-contest-REQUEST at contesting.com

More information about the CQ-Contest mailing list