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Re: Advice on antennas for working the LEO's



At 09:25 AM 2/22/2007, John Kopala wrote:

>If you use an antenna that is small enough to hold and point by hand, you
>will lose a lot of gain vs the big antenna, but it will be a lot easier to
>point.  You still need real time data for the azimuth and elevation and some
>sort of azimuth and elevation aids would help.  Some people enjoy working
>satellites with the Arrow antenna.  Personally, I have not have a lot of
>luck with reading azimuth and elevation, manually aiming, talking on the
>radio all at the same time.

All I need to know is roughly what patch of sky to aim at when the 
satellite rises.  Once I have the satellite, I can follow the signal 
by ear (being a foxhunter helps ;) ), so then I can use one hand to 
work the antenna, one hand to work the radio and monitor 
continuously, so I can make adjustments on the fly (something I tend 
to do "naturally" even when just ragchewing on the local 
repeater).  I've found it more efficient to adjust the antenna by ear 
than to consult az/el tables.  The ultimate computer control - the 
one between one's ears. ;)

With practice, it's even possible to discriminate between uplink and 
downlink fades on FM birds (works for terrestrial repeaters as well 
too!), because there are subtle differences in the (relatively, given 
the limited audio bandwidth) high frequency content of the noise 
during fades, and adjust the antenna accordingly, even if the 
uplinking station is noisy.  And for those who can walk and chew gum 
(or talk and swing beams) at the same time, you can do it while 
you're transmitting as well, if you have a full duplex setup.:)

73 de VK3JED
http://vkradio.com

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