Hi, Tom:

I had almost exactly that problem at my other house about 25 years ago.  It 
happened on 40 meters only.  The shack was on the 2nd. floor.  The cure was 
to attach a piece of 300 ohm TV cable one quarter length of 40 meters to the 
grounding lug even though I had a functioning grounding system. Can't 
remember if I twisted the leads together at rig and open end or only to rig 
end.  Pushed it out of the window and let it hang.  I think I got the 
solution from a friend who had done the same thing and he just let the line 
run around the baseboard.

Good Luck!
Bob Martin
KC3FI

EchoLink Node - 55127
Please visit http://www.wan-leatonks.net.
----- Original Message ----- 
From: "tom behler" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, February 07, 2011 8:58 PM
Subject: interesting RF problem in the shack


> Hi, all.
>
> Well, I know I'm going to get varying opinions on this one, but that's ok,
> since I'm looking for a number of possible alternative causes and 
> solutions.
>
> As many of you know, I have gone back to using my Alpha Delta DXCC antenna
> as my HF antenna, until my Windom, which took a dump on Saturday, can be
> resurrected.
>
> The DXCC works great on 40 meters with both 100 wattts, and my Ameritron
> AL811H amplifier.  However, when I went to do the Cross-Country blind ops
> net on 14.258 yesterday, I had an interesting experience.  Things worked
> great with 100 watts, but when I kicked the amplifier in, and tried 
> running
> things on the usual 600 watts, I ran into problems.  As soon as I keyed 
> the
> mic, the protective circuit in my Rigrunner tripped, and everything in my
> station went silent.
>
> I have no other indications of RFI anywhere else in the house or the 
> shack.
> In addition, my SWR's are good with the DXCC on 20 meters (about 1.5 to 1)
> without the tuner, and obviously just as good with the manual tuner.  I 
> use
> my usual procedure to tune the amp, and everything works there as well,
> giving me forward and reflected power readings I would expect.
>
> Could anyone tell me what you think is going on here?  Do I still have a
> grounding issue of sorts, even though I've gotten no indication of 
> grounding
> issues with other applications?
>
> Other than reducing power, is there anything anyone can suggest for me to 
> do
> to try to solve this problem.
>
> I was thinking of grounding the Rigrunner by connecting a ground cable 
> from
> the cover of the Rigrunner to my common station ground, but just haven't
> gotten to it yet.
>
> It's just a strange problem, and only seems to occur on 20 meters with the
> amp.  I never had the problem at all out in Colorado, where I had no 
> station
> grounding system at all.
>
> 73 from Tom Behler:  KB8TYJ