N13: Amateur radio technical notes.
Remote operated equipment
N13: Amateur radio technical notes.
Remote operated equipment
Remote controlled antenna switch
Suggested antenna switch for 4 antennas with signalling over the
coax cable between the shack and antennas
The electrical circuit is not difficult to build, but the real
challenge is the mechanical construction, particularly to protect
the coax connectors from rain and pollution in the air.
The best solution is of course, to house the box inside a larger
box, but it is possible to use some sort of weather protection
with cables going out in the bottom of a box -
with at least 5cm wide skirt below. The problem varies with the
height and it is worse for the part of tower which is higher than
the roof of the nearby house.
 144MHz pre-amplifier, and 2m antenna switch to choose between big wheel and 2x 9 el. yagies |
 Pre-amps for 70 and 23cm with proper weather protection |
Some FTR (Philips) boxes mounted in the antenna
tower.
The funny side about these FTR CF-boxes is that they were offered
at the local clubs in 1982 (as surplus material from work), but
it was no interest at all. On another hand they became very
popular in Aannaboda VHF meetings (near Örebro), and 250 boxes
were distributed to amateurs all over Scandinavia, also to
eastern Norway, and a few went to Germany and Nederland within a
5 year period..
 |
 |
The highest VHF/UHF/SHF antennas - seen from top of the roof, see
link to the VHF/UHF pages (d); 2x23el DL6WU yagies for 70cm and
2x 9el flexayagies for 2m. 4ft LA6LCA parabolic dish with DL7QY
feed for 1296, 2320, 3456, 5760MHz. The total height is 15m (80m
asl).
40cm offset type parabolic dishes for 3 and 6cm CW/SSB are
planned at 10m above ground. It is also a big wheel at 12m, and a
4 el yagi for 6m on the roof. HF antenna at the moment is only
LA1IC trap dipole.
HF antenna selector panel in my shack using Fernsehen-connectors
994.
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2005.01.07