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

Re: UO-22 azimuth-only system

Hi Dave et al,

Been watching the discussion re AZ-only systems. Back in 1975 a small group 
of us started going off on mountain-topping expeditions to work AO-6 and 
AO-7 and fast-scan ATV. We kept it up for over 20 years. One of my first 
and most successful antenna systems was a phased array mounted on a simple 
frame which allowed it to be tilted over to match the maximum predicted 
altitude of the next satellite pass. It became known as the "flying 
bed-stead" and I wrote it up in our local amsat magazine. It was picked up 
by a couple of the overseas amsat pubs at the time. It could be oriented 
towards the AZ point where the maximum altitude occurred and the high gain 
main lobe of the phased array "followed" the satellite across the sky. The 
system worked very well but was eventually replaced by a short mast which 
had a hinge at the top on which was mounted a second slightly longer mast 
that could be tilted to the max altitude. This allowed a tiny TV rotator to 
give quite accurate tracking using 5 or 6 element yagis. That was also 
published at the time. All good fun in the days before computers when our 
best tool was the 'oscar-locator' but in later years we went to a full 
AZ/EL computer controlled tracking system. No reason the old phased array 
wouldn't still work though.

73 to all,
Bill ... vk3jt ... Milawa ... Australia

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