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Reply To: | Mike Duke, K5XU |
Date: | Sat, 23 Feb 2008 07:57:09 -0600 |
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I lived in apartments for many years, but managed to stay on hf with
whatever amount of wire I could get out a window to a tree.
Howard is correct about a counterpoise.
I had one for 40, 30, and 20 meters. You can connect them all to the ground
terminal of your tuner. I found that I didn't need to remove any of them
from the circuit at any time.
Just as with a dipole or 1/4 wave vertical, the 40 meter counterpoise will
tune 15 meters reasonably, and the 30 meter wire will do the same for 10
meters.
The length isn't too critical. I used cheap speaker wire from Wally World,
which I pulled apart and cut into approximate 1/4 wave lengths for the 3
bands.
The lengths were approximately 33, 23, and 16 feet.
My end fed wire was about 100 feet.
With these counterpoise wires connected, everything tuned much better, even
80 meters. I never tried to wrap an 80 meter counterpoise around the
apartment.
With the wire length I was using, I couldn't tune 30 meters at all without a
counterpoise.
I also made one for 10 and 15 meters, but found I didn't really need them
with the other 3 connected.
When I first started working with them, I would toss the 40 meter wire out
the window late at night in order to have more of it stretched out. I got
tired of having to reel the thing in and out every time I wanted to operate,
and just ran it around the baseboard of my bedroom. I found that running it
that way didn't make a significant difference in the way the antenna tuned
vs tossing it out the window.
You do have to remember to not grab the wires while transmitting. Even at 5
watts they will get your attention!
The counterpoise is a much more economical form of hocus pocus than the
"artificial ground" boxes.
Mike Duke, K5XU
American Council of Blind Radio Amateurs
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