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Re: Uplink Power



Hi all,
About power needed.

----- Original Message -----
From: "Gary "Joe" Mayfield" <gary_mayfield@hotmail.com>
To: "Eddy Jespers" <ejespers@wanadoo.be>; "AMSAT-DL Journal"
<amsat-dl-journal@AMSAT.Org>; <amsat-bb@AMSAT.Org>
Sent: Friday, July 20, 2001 12:56 AM
Subject: Re: [amsat-bb] Uplink Power


> Eddy,
>
>      At the risk of being politically incorrect.  It takes quite a bit
more
> U band uplink than originally thought.  It takes more than AO-13 did, and
> more than AO-10 does when it is working.

I think you are right - but read on.

Last evening with a range of about 30,000 km and a fair squint (8 degrees),
I used first an ICOM 471 (70 cm)with an output in the radioroom of
approximately
20 W.
That produced a usefull signal - but at least 2 S degrees lower than most
other stations. Switching in the PA and running about 70 W put me at the
same level on the downlink. No Leila

The antenna is a 2x19 element TONNA with a gain of 16 dBic. Cable loss
up approximately 2 dB.

Another thing is - was the LEILA operational ?? I did not hear it at all ??
If it was not on - the AGC on AO-40 could be on a high value. That happened
last time the transponder was on. I did not check that.

I also tested the L band uplink with 10 W in the radioroom. Antenna is two
19 turn
helixantennas (WIMO) - gain approximately 18 dBic. Cable loss about 4 dB.
I could hear myself - but need more power.
The stations I worked who used L band uplink used more like 30 to 40 W.

My receive side is two times 16 turn helix (G3RUH), and a system noise
figure
of 1.2 dB.

73 OZ1MY/Ib




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