[amsat-bb] AO-51 L/U SSB/FM mode

Luc Leblanc lucleblanc6 at videotron.ca
Wed Sep 24 08:14:19 PDT 2008

On the morning pass i was able to have a QSO with WO3T Carm and VE3NPC Clare signal where good but manually adjusting the doppler became 
more and and easy with the usage. I guess some adjustment where made live as the audio deviation swing and i think too much make only the 
noise appears too high and it distorded the audio too much. The best setting is where the noise start to increased a bit.

I was able also to determine my transverter IF in zero beating my carrier and checking the frequency on a scope display. 1268.692,100 MHZ 
equal to 144.01355MHZ on the exciter now i will have to figure out how to enter theses values in the tracking programs.

I was able also to confirm my last minute quick station modifications make's a huge difference on the uplink. My previous configuration was 
the FT-847 driving the 1.2GHZ transverter who delivers about 3 watts into a downeast microwave 18 watts amp. The TX line was a 45 foot 5/8" 
heliax feeding a 25 elements loop yagi. In this configuration my results where less than marginal. 

Just before the evening pass i take the amplifier from the shack and i literally planted it over the heliax male connector at the antenna. 
i wrap the amp and the 12V DC line in a clear plastic bag to be able to see if any moisture build up inside,  as the amp heat sink became 
quite hot.

Bingo my uplink is now quite good "lesson learn" put your amp at the antenna not in the shack... I don't figure out why there was so much 
attenuation in the heliax? or it is a lossy coax jumper l used RG-214/U at both end only at the shack i have a SO-250 plug at the end of 
the heliax where i should used an UHF to BNC adaptor??? Any ideas!

Finally this SSB L band experience was a good one and with the satellite deviation tweaking (Thank's to the control teams) this mode is 
quite effective even if it still not a killer one.


Luc Leblanc VE2DWE
Skype VE2DWE


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