[Antennas] Cubic Quad Info

Sun, 8 Dec 2002 19:49:32 -0000

Subject: [Antennas] Cubic Quad Info
> Greetings, I've been looking at a couple of the online Quad Calculators.
>> Something troubles me with the results and wonder if it's me or the
> calculator.

Hi Ray..
 It's not you... These calculators are a very rough guide
only..
For a given wire size, the formula will vary with frequency, because the
ratio of conductor size to loop area varies with frequency. There have been
some very good articles written on the subject.. If I can find them I'll
mail the info to you, but all the info is available on LB's site anyway.
 Unfortunately, the best practical " formula" is...Cut it too big
(100/f for driven element) and start pruning...... If you're using insulated
wire, it'll be approximately 2% smaller than for the bare stuff, depending
on the insulation type.
 The good news is, that when you've successfully built and tuned your
antenna, you can work out an accurate formula for that design of Quad, using
that particular type of wire. You can then replicate that design easily
enough. The actual formula will be slightly different for each band..
It's hard work, but worth it in the end...Most important...Write down all of
your measurments carefully when it's working... If you lose it in a storm,
you can rebuild it easily, without all that tuning etc.
73
John EI7BA http://www.iol.ie/~bravo/