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Re: S-band success



Glad to hear of your success Bruce! I'm thrilled to see one of these downconverters in use. Other than a retuning, what did you have to do to make it work for satellite? So often I hear the complaint that S band is too expensive for the ham on a budget, and we both know thats not true ;-).

I can assure you the S transmitter stays on the entire time the mode runs. The PL is only capable of gating the audio to the S tray, not switching the transmitter. Usually L/S is run without tone access, so when no one is transmitting up to the sat, the downlink is just repeated static...sort of hard to differentiate from normal noise. If the PL access is on (and I don't think it is) you'll only hear a carrier with no audio between transmissions. I can't explain really why there was no signal when no one was talking though.

With SSETI almost literally sitting on the pad (or actually in the hole!) all us S band Junkies are about to get a "daily driver" to play with.

Congratulations again!

73, Drew KO4MA




-----Original Message-----
From: Bruce Robertson <broberts@mta.ca>
Sent: Oct 25, 2005 11:47 AM
To: Andrew Glasbrenner <glasbrenner@mindspring.com>
Cc: brobertson@mta.ca, amsat-bb@amsat.org
Subject: [amsat-bb] S-band success: was AO-51 S-band downlink on mode L/S always  on?

Thanks to Drew and Steve for their quick replies to my questions. Drew deserves
the Mind-Reader Award for having guessed that I was trying to peak the
downconverter with the AGC enabled on my IF rig. I re-tuned it and got probably
about 10-15 dB better sensitivity. On the 14:20 pass of AO-51 I went outside in
the beginning of our post-Wilma storm and at about 10 deg. elevation heard W2XB
calling. I lost him soon after, perhaps because my house blocked the rest of the
pass, or perhaps he tired of calling with no answers.

With a K3TZ patch antenna made out of thin copper sheet, my TH-D7A indicated a
full-strength signal when he was transmitting.  Oddly, when W2XB wasn't
transmitting, I neither heard nor saw an indication of a signal. Perhaps the
S-band transmitter does, in fact, switch on and off with the L-band uplink.

In any case, all this is good enough for me to add the S-band converter
alongside the 144 and 435 MHz yagis on my about-to-be-raised rotatable array.
I'm thinking the approx. 8 dBi gain of the patch antenna will nicely match the
pattern of the four- and eight-element yagis if everything is tilted at a fixed
10 deg. elevation.

73, VE9QRP
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