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Re: link budget P3E



Robert
For AO-40 1.2 GHZ uplink
I started with 10 watts at a 16 dBd gain M2 linear polarized antenna.
It worked for CW, RTTY and PSK31.
It did not work very well for SSB.  At very low squint angles I could make a 
SSB contact
but rag chewing was very difficult to impossible at best.
I then added a 2nd 16 dBd gain antenna for a total linear gain of 18.7 dBd..
I could then work SSB better , and occasionally rag chew at very low squint 
angles.
Next step was to configure the 2 antennas into a 16 dBd circular 
polarization configuration.
It seemed to be slightly better than linear polarization setup.
Final step was to add a 100 watt output power amp AT THE ANTENNAs.
At apogee that was great.  At low squint I even had to crank the power back
At squints over 10 or 12 degrees, the full 100 watts was needed for good SSB 
contacts..
Just a few days ago I reluctantly disconnected the PA and brought it in the 
house since the enclosure it was in was disintegrating (actually 
disintegrated would be a better description).
Regards and anxiously waiting for the next HEO !!
Rick
K9KK

----- Original Message ----- 
From: "Robert V Johnson" <w7lrd@juno.com>
To: <amsat-bb@amsat.org>
Sent: Monday, January 09, 2006 10:22 PM
Subject: [amsat-bb] link budget P3E


> Hello
> I'm getting into an area I'm not at all familiar with.  In the past I
> just would plug and try.  I need assistance in figuring out if what I
> have is capable of sucessful 'L' band operation with the next HEO.  I
> have an IC-1271A with 10 watts output on 1.2ghz., 60 feet of  50 ohm
> hardline, and a 15db gain helix.  I'm good with the downlink part from my
> AO-40 hardware.  All my 1.2ghz  equipment has been aquired after the
> failure of AO-40.  I would like to be prepared before launch.
>
> 73 Bob W7LRD
> Seattle
> ----
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