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I am moving into a 55+ community, relatively small lots, single story frame and stucco homes in close proximity to neighbors. However, one edge of the lot is parallel to a golf course and has a steel fence (welded horizontal stretchers, with vertical bars about every 5", about 5' tall).

I am thinking of driving steel post at each corner of the lot line and stringing a dipole with support cable from the post, parallel to the fence. Planning to use the antenna for HF. If the antenna is sufficiently close to the fence, I might be able to get away with it.

  1. How much will the fence interfere? How far away from the fence does the antenna need to be?

  2. Generally, how much power will cause RFI interference to the neighbors in this neighborhood? Said another way, dare I run at 100 watts?

Thanks for your help. Greatly appreciated. KK7NTU

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  • $\begingroup$ honest question: roughly one in 78 or so people over 65 in the US holds an amateur license, with high positive correlation to house ownership, so there's probably licensed folks in your neighborhood. Wouldn't it be wise to ask the local amateur radio club, if any, whether someone has solved the question on how mount an antenna HOA-compatibly? Alternatively, wait until someone strong is on the air, do a bit of fox hunt, knock very politely on their door (bring cake?) and tell them about you wanting to put up an antenna, asking what they did? $\endgroup$ Commented Jul 10 at 9:52
  • $\begingroup$ (other than that, I do believe that we're in an age where we can put antennas where it's geographically advantageous instead of necessarily close to one's living room, i.e., on hills / towers nearby, and work with these remotely. Especially if it turns out you have neighbors who'd also want to operate, but shy away from putting up antennas (you, willing to drive your own posts into the ground might be the fittest of the lot!), that could be an option where you share cost of setup.) $\endgroup$ Commented Jul 10 at 9:56

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It seems like there is a conflict in wanting the antenna to be close to the fence so it isn't noticeable, yet far from the fence to reduce its effect on the antenna's radiation.

Also, you would want the antenna to be at a sufficient elevation for a good radiation pattern. Do a web search for "how high should my dipole antenna be".

I suspect that having your dipole antenna be parallel to a metal fence, and perhaps somewhat close to it (say much less than 1/2 wavelength), will significantly hurt performance. You will have electric fields parallel to the fence and the RF energy will couple into that fence -- some of the energy will be lost, some might be re-radiated, but who knows.

Ultimately, trying is out is the answer. Use something like WSPR or the reverse beacon network to get objective results.

You could try to simulate that setup using one of the NEC-based software tools, but I'm not hopeful that you will get accurate results without lots of work.

Personally, I would look for another solution. I am in a similar situation as you, and in my case I went vertical, which of course has its own issues.

Regarding RFI to neighbors, it is again hard to answer due to the complexity of RF behavior, and it depends on what kinds of electronic devices your neighbors have. The first data point is whether running 100W causes problems in your house. If none, I wouldn't hesitate to run 100W as needed.

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To directly answer your question

There will definitely be some kind of interaction between the fence and your proposed antenna. It's worth a shot though! Do a trial run with a temporary setup to see what happens. You may decide it's good enough (or even better). Otherwise, you've got some data and experience you can share with the rest of us.

Re power... it depends.

For example, there's a huge population of AFI/GFCI breakers that didn't have RF shielding, and one neighborhood I lived in was plagued with those. I don't think I tripped any neighbor circuits but I def tripped mine before I replaced them.

In another neighborhood, I was able to trigger several townhomes' smoke detectors when transmitting 25W on 2m. That was pretty special.

With a direct answer to your question out of the way...

Now I'm in brainstorm mode.

Some options that pop to mind:

The fence is your antenna

This is a different configuration that your initial proposal. Connect one end of the fence to the shield of your feed point. Connect the center (am assuming you run coax for your transmission line to the fence corner) to some magnet wire (or something similarly invisible to the casual observer) that you suspend from a support off the fence to the peak of your house or a tree or even just make it a vertical hamstick that you put up as if you're portable.

The fence is your antenna (another option)

Load up the fence as your antenna! Run a counterpoise perpendicular to it on the ground.

Fly a flag

Flagpole antennas are a thing! And many HOAs will allow them.

Attic space doesn't have to be wasted space

By running an element from the center/peak of the attic space to a corner and then along one edge of the roof, and then running the other element as a mirror (opposite corner and opposite roof edge) you get a very workable solution that the HOA can't complain about. I've personally run 100 watts with this configuration from outside of DC and hit Poland, Germany, UK, South Korea, and exotic locales such as Arizona and California! 17m, 20m, 40m were my bands of choice at the time, YMMV.

Remote operation

Be sure to take Marcus's suggestion to heart! Figuring out a remotely located and controlled HF station can be very satisfying, and it's reasonable to see if you can find some other hams in the neighborhood to collaborate with.

All of these require some more attention to detail

For example, make sure you have a proper balun/RF choke at the feed point. And make sure you have one at the radio too to make sure you're not using the coax shield as a noise capturing antenna. If you load up the fence, you'll want to keep an eye out when operating to make sure you're not transmitting while someone is sitting on it or you'll be creating some hot cross buns. Etc etc etc.

I'll add more as I think of it (and invite others to do the same).

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