[ICOM] PRO III and shut down

[Bruce]

Does the PRO3 work ok barefoot?

-----Original Message-----
From: icom-bounces at mailman.qth.net [mailto:icom-bounces at mailman.qth.net] On
Behalf Of hamop
Sent: Monday, July 02, 2012 2:59 PM
To: icom at mailman.qth.net
Subject: [ICOM] PRO III and shut down

    Hello all ... need some assistance. Never had this situation happen
before. Today while operating on 20m CW I noted no output, well maybe 5
watts, and I thought maybe the PS125 had blown an internal fuse for some
reason. I was running about 50 watts to a Titan amplifier at the time, my
main setup for 3 years now. Well, rather than tear into the PS125, I put a
PS85 in line and again a full 100 watts immediately. So thought the PS125
had truly blown a fuse. Well, after another shutdown to about 5 watts I
thought the PS85 had also blown a fuse. 
   As one last effort, after about 5 minutes, I returned on the PS125 and
PRO III and a full 100 watts output again. I found out that if I turned on
the rig and did NOT hook the PTT line to the Titan, all seemed to be OK with
no "shut down".  But, even keying the amp with an EXTERNAL foot switch and
trying to drive the amp, bang ... again just 5 watts out, but it returned to
100 watts after another 5-6 minutes.  Is the PRO III or PS125 and PS85 (
unusual for both to do it) heating up inside causing the shutdown by some
quirk feedback from the Titan amp?  Seems like if just barefoot straight to
the antenna, I can transmit 100 watts as normal with NO shutdown. Puzzling
to me for sure. Appears since same thing happened to the PS 125 and 85 that
both should not have developed the same 'shut down' issue. That leaves me
wondering if my PRO III finals are overheating some how?
  Thanks for any suggestions.  Receive is fine the entire time. If I shut
down the PS and PRO III for just 3-4 minutes, the output may drop quickly
with about 20 seconds of CW and the longer units are off , the longer the
power stays up.
73
San K5YY
   
----
Your Moderator: Dick Flanagan K7VC: icom-owner at mailman.qth.net
Icom Users Net: Sundays, 1700Z, 14.316 MHz
Icom FAQ: http://www.qsl.net/icom/
To support QSL/QTH.net: http://www.qsl.net/donate.html