[Kenwood] re TS-940S alc/pwr problems

[Jerry Holcomb]

Hi Fern.  Your problem is connector number 8 on the front left of the PLL 
board which you can see when the front  panel drops down.  This connector 
provides a 10 mhz signal to the carrier board.  When it is intermittent, it 
gives the exact symptoms you describe.  Dropping the front panel changes the 
position of the wiring harness that causes the intermittent to come and go. 
I had one I worked on in which the header was not soldered well to the PLL 
board but usually just cleaning the connections with De Ox It takes care of 
it.  Pay attention to the earlier posts to this thread about the propert way 
to drop the front panel.  You must let it pivot from the rear round headed 
screws not the countersunk screws that secure the cast front panel to the 
sheet metal ears.   The diode and resistor sounds like a post design 
manufacturing change.  73s  Jerry N0XWR

-----Original Message----- 
From: Fern
Sent: Saturday, January 01, 2011 12:48 PM
To: Kenwood List
Subject: [Kenwood] re TS-940S alc/pwr problems

       I have been working on a recently acquired  early production TS-940S
(serial #5110XX) . I corrected a poor receiver sensitivy problem with
re-alignment but the transmitter had low  or non existent alc reading plus
intermittent output power(15 watts only). I had to replace two of the
lithium batteries to get the memory functions to work and while I had the
front panel loose, the radio suddently had full power output with lots of
alc action. When I re-installed the front panel, then the same old problem
of low power and poor alc came back.
     Here's what I found. A previous owner had installed a diode in series
with a 15K resistor from a brown wire then tied into one of the rf power
pots (just behind the front panel) which is in the switch unit X41-1600-00.
I have done a google search but cannot find any info to do with such a
modification.
     Any info or guidance on this would be greatly appreciated.

              Happy New Year from Fern    VE7GZ


______________________________________________________________
Kenwood mailing list
Home: http://mailman.qth.net/mailman/listinfo/kenwood
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Kenwood at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html