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Old October 10th 04, 09:53 PM
Bob Bob
 
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Gidday Johann

Simple balun you can use in this case is a "choke" balun. Just wind
about 5 turns of the coax in a 100-150mm circle near the antenna
feedpoint and tape it up. This will almost eliminate all of the line
radiation.

Another way is to make a folded dipole. This has a nominal 300 ohms
input impedence and feeding this with a 4:1 coaxial balun (200 ohms) is
only a slight mismatch. (1.5:1 VSWR) I have also heard (but never
checked/proven) that a folded dipole antenna couples to "space" better
than a simple dipole. (ie is more efficient)

If you cant find an internet refernce to the above then pls ask for more
info.

Cheers Bob VK2YQA

Johann Höchtl wrote:


Hal Rosser wrote:

You'll find a simple dipole may be your best choice for starting out.
Most important of all is to get the antenna up high and use vertical
orientation.
If I recall, each leg of the dipole should be around 102 inches.



102 inches, or 2.59 m for a metric man like me. That's right. But i
bother how i can go from balanced to unbalanced. I use rg58 wire and i
do not want to radio interfere my neighbours nor let my radio go up in
smoke.

So i guess i need a balun. The impedance at the connector from antenna
to wire should already be more or less 50 ohms, but it's balanced.

What would make an easy though effective 1:1 balun?