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Downconverter noise

Hello All,

I recently bought an AIDC downconverter and according to Bob's instruction 
sheet I should have an S5 reading with no signal. There is no increase in 
noise when the power is applied to the downconverter, however it does draw 
180 ma at 20 volts so it's not dead. The cable to the downconverter is only 
about 2 metres in length, so I expected some sort of reading.

I found that I do get an increased S reading when I point the downconverter, 
with it's patch aerial in place, at the computer. So, there is some life 
within the grey box.

Should I have an S 5 reading just with the downconverter sitting on the bench, 
or should I only expect an increase in noise when the downconverter is fixed 
to the dish?

Another question, at the focal point is a thick circular aluminium plate which 
has three grooves machined in it and a central hole about 70 mm in diameter. 
The fellow that I bought the dish from referred to it as a choke. I have had 
the patch aerial mounted directly to that choke, could that be a problem?

Finally, my dish is a steel petal type 1.8 metres in diameter. It's a little 
awkward to maneuver but I think I've been reasonably accurate in pointing it 
in the correct direction. Should I expect to hear the beacon if I'm say 10 
degrees off?


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