Tom,
A quarte4r wave for twenty meters is about 16.5 feet, using 14.1MHz.
----- Original Message -----
From: "T Behler" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, July 28, 2006 3:08 PM
Subject: Re: continuing RFI problems in travel trailer
> Steve:
>
> I've contacted the maker of the antenna, and he has no other suggestions
> aside from being extremely sure that I have a good grounding system, which
> I
> think I do.
>
> I don't really have a convenient way to try the rig on a 12-volt battery
> right now, but I may be able to work out something.
>
> The quarter wave length of insulated wire attached to the ground lug of
> the
> rig sounds intriguing. I assume that a quarter wave for 20 meters would
> be
> about 8 feet? What gauge of wire should I consider, and where to I attach
> the other end?
>
> Thanks, and 73 from Tom Behler: KB8TYJ
>
> ----- Original Message -----
> From: "Steve Forst" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Friday, July 28, 2006 3:01 PM
> Subject: Re: continuing RFI problems in travel trailer
>
>
>> 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
>> >
>> >
>> >
>>
>
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