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Minimalist equipment



Hi  Ed / All.

After reading about the 18dB of AGC I decided to get up at 02.00 local and 
see how sensitive the transponder is when there's only a few users. (mid 
atlantic to Japan in the footprint)

TX:  9 element Yagi (Tonna) on 435 with a Bird 43 Wattmeter at the antenna.
RX:  26 turn helix and Drake 2.5dB noise figure + FT290

With the antennas in the shack pointing out of the correct window and aligned 
with the satellite I reduced power.  With only two other stations on AO-40 at 
the time the minimum power for 100% copy was 6 Watts RF out. 
The Yagi was quoted as 13dBi by Tonna so I guess that's about 73 W  ERP 
referenced to a dipole.  Pretty good...

AO-40 was 39,000km range with an excellent squint angle at the time.
This is exceptional. Under normal conditions I really need a small dish for 
anything beyond 40,000km.

As a bonus I managed to work JA6BX and 4X1AS later in the orbit. Great fun!

73

David  G0MRF
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