[bars] Physically small 440 antenna?

[William Smith]

As many of you know I've moved from a 4BR house with lots of antenna freedom to a 2.5BR condo in FL in an HOA, and have discovered that while concrete and steel are good structurally, they aren't much good for RF.

The good news is I've got a plan for a temporary antenna, and the http://www.sarnetfl.com repeater system is all 440, so I don't need a physically _large_ antenna.  I didn't _need_ the SARNET system, because Ian missed us except for some wind and rain, but I'd like to be ready for next time.  8*)

I've got a 2M/440 magnetic mount antenna that I could put on a bracket sticking out from my window, but then I need a bracket that's magnetic and is large enough to present some ground plane, so the whole thing rapidly gets large, which makes it worse for high winds and is more visible to the HOA Police.

I've built 2M Copper J-Poles before, and am contemplating a 440 Copper J-Pole, but obviously the tolerances get tighter as the frequency goes up, does anyone have any experiences building a Copper J-Pole for 440, or have any other suggestions for physically small 440 antennas?

I _could_ put the traditional 'mag-mount on a cookie sheet' in my attic, but accessing the attic is a bit of a nightmare, as it's just been filled with blown-in fiberglass insulation, and I have a tile roof, so the 6-foot height gain might not help much.

Here's the current plan:

Outside my office window (which faces the nearest SARNET node), there are three slots in the window track to let any water drain out:



I'm thinking a piece of metal (steel or magnetic stainless ($$$) if I go the mag-mount route) with a tab that goes into that slot, bolts down to a fitting on the concrete still, and sticks out a wavelength or so (2-3 feet).  If I save the mag-mount for the car, and use an antenna that doesn't need a ground plane, then an aluminum shape (plate, U-channel, L, T, square bar, etc) would work well and be less expensive and still rust-free.

Here's what it looks like from the outside, so I definitely want to get it away from the building:


Here's the ruler stuck in the slot and the mag-mount antenna for scale, as you see the bracket would have to be pretty big (3.5" minimum) to fit the mag-mount, and adding a useful ground plane would make things a lot worse):


And then what?  Any thoughts?  Any experience with homebrew small 440 antennas?  My Baofeng with the 'big antenna' almost works inside, and the mag-mount on the window sill is OK until I pull down the (metallized) window shade, so I don't need much...

Thanks in advance!

73, Willie N1JBJ

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