In a message dated 11/6/03 9:09:44 PM Eastern Standard Time, W5PR@swbell.net
>>Two element quad with .15 wavelength spacing one element on each side of
the tower in a "diamond" configuration (points up, down, L & R) bottom about
off the ground, feeding the DE at a corner for vertical polarization.
1. How much might the vertical tower in the middle of a
vertically polarized quad degrade its performance?
2. What kind of a bandwidth should I expect? Can I tune it for
3.7 MHz and work from 3.5 to 3.9 MHz?
1. To find out, it would help to model that in software. It depends on
dimensions and stuff around it. If there were right dimensions, the tower could
as "dummy" director like in OWA antennas and widen the B/W.
2. That is normally too much B/W to expect. You could tune it for minimum SWR
using tuner or matching, but gain and F/B would be off at extremes. Normally
it is advisable to use loading stub or coils to insert with relays in both
elements for lower end of the band.
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
TowerTalk mailing list