Counterpoise design

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26mb04
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Counterpoise design

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I'm trying to work out an ideal length/design for a HF portable counterpoise. It'll mainly be used on 20m. My question is, is it better to have a smaller number of longer wire lengths, or a larger number of smaller ones?

I'm going to be using an old 20m long extension lead, which has 3x thick steel wire stranded conductors. I haven't cut it yet, as I thought I'd get some advice first.

I'm not too worried about size, It'll be used for overnight/weekend use, so it's OK if it ends up taking up a rucksack or something.
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ch25
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Re: Counterpoise design

Post by ch25 »

Ground or elevated?
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Re: Counterpoise design

Post by 26mb04 »

Ideally elevated, but possibly just thrown on the ground. I wasn't going to ground them (they'll be connected to the radio ground).

I'm building my own version of the PRC320 ground plane kit, seeing as it's just a very expensive reel of wire.
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Re: Counterpoise design

Post by ch25 »

Elevated radials should be resonant and 4 per band is enough.
Laying on the ground or buried 32-36 at least. 20m band, 5m long radials should do the trick.
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Re: Counterpoise design

Post by 26mb04 »

That's great, thanks Chris!
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Re: Counterpoise design

Post by ch25 »

...and forget about steel wire.
You can't have too many antennas...
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Re: Counterpoise design

Post by MorseMan »

As many radials as possible using copper wire is my advice, you can go down to 1/8 long if using 64 possibly 32.
If you think about it, When you mount a 40m antenna on a car your vehicle is not 10m square but it still works with a small counterpoise.

Just use as many as you can but after 64 you see diminishing returns.

You can use a tape measure as a tuneable counterpoise at a push or even as a dipole if you use 2.
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