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[WB2LYM]

Hi,

I live and work in an RV. part of its electronic ecosystem is a commputerboard that controls lights and  few other functions.

I cannot keep an antenna outside, as I am in an RV park. So I have an MFJ Super Q loop near the other end of the RV.

the problem is that it is right above this computerboard which is under the floor, accessible from an outside compartment.

MY QUESTION is: From a perspective of needing to avoid damaging this RV board, but wanting to operate and QRP levels while inside the trailer (better than nothing), I can't be sure how much, if any, RF will get into that board and if any does, agove what power level I might be taking too much risk.

I get that nobody can answer this without being here, but if someone might at least choose to speak in some generalities to me, with whatever opinions might be offered, I would really like to hear them.

PS I am guessing that this computer board in the RV has little to no shielding of its own.

PPS for that matter, right near the barefoot transceiver, I also have regular computers, too....so maybe it is easier for someone to opine about RF getting into those and I can make some educated guess about what else might be happening.

In any event, thank you in advance for offering "whatever" you can.

robert

[W4FID]

I often use a loop when operating portable. The loop has a deep null perpendicular to the plane of the loop. That helps as I get RF in the laptop that freezes the CAT when operating FT8. So I have to shut down the laptop and re start it when that happens. But no harm is done and I just try again at lower power till I have a location and orientation for the loop and power level that doesn't cause a problem. No harm done -- just trial and error and then I am at whatever power and directivity the set up allows. YOU HAVE A SIMILAR BUT DIFFERENT PROBLEM. The control boards could be at risk and the RV likely has lots of unshielded wiring between stuff and them. I wouldn't risk it. Erratic operation is grief. Fried boards is REAL grief! Many loop manufacturers offer remote tune loops that an be located up to maybe 50 feet away and can be set up easily/quickly on a camera or speaker tripod. Maybe a sand bag o the leg if it's windy. Orient the loop so the RV is in the null and stay with as low power as you possible can. Work whomever you can work on whatever band and mode you can and enjoy the QSOs you do make. Or get a nice mobile set up and enjoy it from the picnic area, overlooks, etc.

[N7WE]

Robert - I'm curious about the comment "I cannot keep an antenna outside, as I am in an RV park."  We traveled in an RV for many years (sometimes 9 months out of the year) and I used an EagleOne vertical mounted off the rear ladder and the RV chassis as a counterpoise.  I never once had any complaint from an RV park, and that included National Parks, State Parks, Corp of Engineers, as well as hundreds of commercial RV parks.  Since the antenna was attached to the RV and not placed on their ground or in their trees, there was no issue.  A common mode choke at the feedpoint of the vertical eliminated the only coach RFI problem encountered - furnace blower motor starting when I went to 100W.  Also, the EagleOne was an effective antenna, and I was able to work most of the world (except eastern Asia) from locations throughout the lower 48.  Don't give up on the idea of an external antenna!

[W1MOW]

I also operate from a travel trailer 6 mos out of the year. I have never had a problem using a portable vertical antenna that I put up/down as I need it. Sometimes I just move it to the back of the trailer out of site. (Although not really.) Sometimes I put up a Sypder Beam 43' fiberglass pole with a EFHW in the early evening.

We also have camped in National/State Parks and commerical campgrounds. We always ask for out of the way sites where it is less likely to bother anyone. By evening time, most campers are by their fires drinking beer, not really noticing anything. If the campground complain take it down and apologize. Remember it is sometimes easier to beg forgiveness than to ask for permission.

Our Lance TT power supply reacts to VHF high band trasmissions. Not sure I would risk a motorhomes computer control system to near field RF.

Gary W1MOW

[WA3SKN]

Use metal screening (ventilation) or aluminum foil to surround the computerboard in a "Faraday shield", then ground it.
RF stays out, computer noise stays in... problem solved!

-Mike.

[WB2LYM]

first, thanks to all who wrote me. it reminds me of why I have been a hame for so many years, and especially as I am now a senior, and by myself, how being a ham means always having some good friends out there!

as to putting up antennas, the park I am in has restrictions about such things. furthermore, if there are any RFI problems, I don't want to have to deal with all that and neighbors.

I do have a tarheel antenna (had it for 7-8 years and never find the time/wherewithall to put it up, which I could mount on my truck and run a discretely placed wire, but I am 74, unwell, and that is unfortunately a big effort for me, so I am trying to take some easy ways out on this, never mind the restrictions. indeed, for that matter, I could just put this super Q loop outside and run a wire inside, but that will bring all those questions and concerns.

as to the kind person who suggested a faraday cage on the board I am concerned about, that is a great idea....indeed, I have, given my dystopian views of what may happen in the US in the coming few years, many electronic and backup items wrapped in or stored in faraday packages, so to say...............BUT, this board is mounted in the RV in such a way that there is no way to take that good suggestion...so I am still left with the basic challenge.

anyway, thanks again all for the quick and great suggestions.

robert