[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: Project help.

 kd9kc@elp.rr.com writes:

> 	Any consensus on fiberglass Vs. Steel cross-boom, cables securely
> taped on the antenna Vs. hanging loose, and antennae mounted + or X.

The discussion about metal versus fibreglass (English spelling) is almost as
strong as code/no-code (DONT START THAT AGAIN). My 10c worth:

If you need to squeeze the last decimal of a dB out of the system, go for
fibreglass. Metal booms do a few things to the signal but not that much and,
hey, P3D is supposed to be easier than earlier birds. I have never felt the
need to go looking for fibreglass and so my cross- and ordinary booms are
all aluminium tube. 

Same story for where to put the feedlines. I taped mine to the antenna boom
(antenna is mounted X-style, not horiz/vert) back along the antenna then put
them along the cross-boom. Taking the cable out the back is fine but when you
rotate in elevation it gets complex and (IMHO) not necessary. My thinking is 
that the antenna was designed with a metallic boom so some extra metal (the 
cable) won't make much difference. I worked the other P3 birds with no 
difficulty with a 9XY on 2m and a 12XY on 70cm. Arrays are about 9ft apart 
on the boom with other (microwave) antennas and 2m/70cm ground-planes inside 
the 2m/70cm beams.

Richard W L Limebear G3RWL
FOC # 1188

          So many beautiful girls ..... (sob) so little time
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org