Tom,
A lot of good advice thus far.  Can you take the rig off  the a.c. 
completely, by  trying it on a 12 volt battery and see what happens?

What about a quarter wave of insulated wire for 20 meters attached to the 
ground lug of the rig?  Some people have success with this  in a home 
station where  there is  rfi on a particular band, but don't know how it 
would  play in a trailer situation.

Have you contacted the mfg of the antenna?   He may have heard of something 
similar from other customers and perhaps has an answer.


Good luck, Steve KW3A



----- Original Message ----- 
From: "T Behler" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, July 28, 2006 1:19 PM
Subject: continuing RFI problems in travel trailer


> Hi, all.
>
> I hate to bug everyone again about this, but I continue to have a nagging
> RFI problem in the 18-foot Fleetwood Pioneer travel trailer that my XYL 
> and
> I recently purchased.
>
> To review, when operating HF, I tend to cut off the air conditioner 
> whenever
> keying up on CW.  I don't trip the GFI circuit breaker--I just cut the 
> unit
> off, and it eventually re-sets itself and resumes normal operation within 
> a
> few minutes.  The problem occurs mainly on 20 meters, although it does 
> occur
> on certain frequencies in other bands as well.  I have found the problem 
> to
> occur even when reducing my power from 100 watts, say to 50 watts.
>
> My HF rig is an Icom 718, and my antenna is a Predator screw-driver-type
> antenna mounted on the back of the trailer.  I use a device called the
> Turbo-tuner, to be sure that the antenna is indeed resonant on my 
> operating
> frequency.
>
> The antenna itself is grounded to the bumper of the trailer, and I have
> installed two other grounds.  One is a ground from the 718 to the frame of
> the trailer, and the other ground is an earth ground that runs from the 
> rig
> to a grounding stake outside of the trailer.
>
> I am getting more and more stumped with this problem, although I have two
> additional thoughts.  Let me run them by you here;  I just don't want to
> spend more money unnecessarily on this problem:
>
> 1.  I run the 718 with an MFJ Mighty Lite switching power supply.  I think
> it's the 4125--it has 25 amps surge, and 22 amps continuous.  Could this
> type of supply be causing the problem via some sort of stray current flow?
> Should I try an old transformer-type supply, such as an Astron RS20, to 
> see
> if the problem disappears?
>
> 2.  I have the rig's power supply plugged into a relatively inexpensive
> power strip, since I sometimes plug my laptop into it as well.  Is there a
> higher-quality power strip that I might want to look at?  Some have
> suggested a power strip with something called a power isolator in it, but
> I'm not quite sure what it is.
>
> Please give me your feedback on both of these possible suggested 
> solutions.
> Or, if you have any other suggestions, please send them to me.
>
> Some have suggested trying to put a capacitor across the leads of the
> trailer's thermostat unit, but I really am hesitant to do that, at the 
> risk
> of somehow voiding the warranty on the temperature control system.
>
> Thanks for anything you can suggest.
>
> 73 from Tom Behler:  KB8TYJ, Big Rapids, MI
>
>
>