[amsat-bb] antenna rig

["Gerhard Paul" <df6sw@xxxxxx>]

hello to everyone,
as a newcomer in the satellite field, I have what I call a circular
polarized antenna rig presently consisting:


- vertical mast
- horizontal elevation rotor beam

    these two elements made of glassfiber reinforced plastic tubular
material, i.e. non-conductive material

- combined elevation-azimuth rotor
- 2 m crossed yagi
- 70 cm crossed yagi

This rig is now to be completed by the coax cables, two for each antenna.

It is claimed that mast and elevation rotor boom must be of non-conductive
material. If these two elements were of conductive material, say aluminum,
this would make possible detrimental interaction between the two yagi
antennas.

As a consecuence thereof, it is also claimed that the four coax cables must
hang down from the rar ends of the antennas in loops of adequate size. If
they were attached along the antenna boom  and further along the elevation
rotor boom to the mast, this would offset the effect achieved by using
non-conductive material for mast and elevation rotor boom, all the more so
as I have in mind to attach a small diameter copper tube or rod parallel to
the mast as a lightning protector.

I should very much appreciate any comments, suggestions and advice from more
experienced operators. Thank you.

Gerd, DF6SW


----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org