On Wed, 26 Jan 2005 12:31:40 -0800, Frank Gilliland
wrote:

On Wed, 26 Jan 2005 19:52:11 GMT, Lancer wrote in
:

On Wed, 26 Jan 2005 08:29:08 -0800, Frank Gilliland
wrote:

Okay, I've been looking for a Super-Scanner for a while and can't find
one for sale. So I decided to make my own. The manual has enough info
to build a pretty close copy except for one detail: the boom length.
What should the spacing be when one dipole is the radiator and the
other two are reflectors?

And would there be any advantage to adding a little reactance
(electrical length) to a dipole when it's switched in as a reflector?


Isn't that already done by the relay box? There is 29' of coax hooked
to the undriven elements.


I think that's 29 inches, not feet. But you made me realize that the
feedpoint impedance of the dipoles is going to be lower because of
their proximity to each other, and that coax is probably cut to make a
conjugate match. At least it's possible. Maybe I'll just go with a
phased array.....



If its 29", then those elements at the most are 29" from the center
hub. I think you would probably be happier with a phased array. A
lot easier to control your patterns and matching.

If qsl.net ever comes back up, this link

http://www.qsl.net/ve3sqb/

had a program to design a super scanner.