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RE: Help with L1 uplink on AO-40



I was on L band last night around 4:00 to 5:30 UTC I was working L1 with no
problems. I have a 12 foot dish with a tri-band patch feed and feeding it
with an IC-910H at about 10 watts through 75 feet of LMR600. At this time
the squint was about 18 degrees and decreasing to 12 or so. The L band
appears to be more sensitive to squint than U band and I need to run 10
watts down to about 10 degrees, then it decreases it until I only need about
2 watts below 5 degrees. Hope this helps.

Gary Gonnella W6RYO
gary@w6ryo.com
http://www.w6ryo.com


> -----Original Message-----
> From: owner-AMSAT-BB@AMSAT.Org [mailto:owner-AMSAT-BB@AMSAT.Org]On
> Behalf Of Joe Steinmetz
> Sent: Saturday, January 04, 2003 10:32 PM
> To: amsat-bb@AMSAT.Org
> Subject: [amsat-bb] Help with L1 uplink on AO-40
>
>
> Hello,
>
> I am debugging my ground station for AO-40 and was wondering if
> someone who
> might have been using the L1 uplink tonight could tell me how well it was
> working? I was just barely able to hear myself on the downlink, however I
> could hear the beacon and many others well above my signal level. I am
> assuming that my receive setup is OK since I could hear myself (in the
> noise) and others (well above the noise) and the beacon (very strong).
>
> At the time of my experiment (1/5/03 05:00 - 06:00 UTC) the
> squint was about
> 12 degrees (assuming I set Nova up correctly).
>
> I am thinking that I have a serious uplink problem. I have two
> 12-turn-helix
> (RHCP) phased for approx 17dBic of gain, with about 60 feet of LMR-400
> ultra-flex and a SSB 80watt amp feeding the system. I am loosing 3.4dB in
> the cable run and according to my directional wattmeter I am
> getting 2 watts
> reflected. Could something be wrong in the phasing that wouldn't
> show up as
> a reflected energy? I am thinking of swapping the phased helix out and
> replacing it with a 22 element yagi just to help isolate the problem.
>
> I only plan on running enough power to get my signal 8dB below the beacon,
> but right now, I am way below that.
>
> How much power are others using for their L band uplinks? And what antenna
> (and gain) are you using?
>
> Any thoughts?
>
> Joe
> k6sat
> ----
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