[amsat-bb] EsHail Microwave transponder satellite

[Rico van Genugten]

Hi Stan (and others),

For the downlink I'm going to use an off-the-shelf dish and LNB coupled to
an SDR. The LNB should have high gain and be very frequency stable. The
Octagon Optima series LNB's get a lot of praise and are very well suited
for this task, and they're cheap too: I picked up one for about 15 dollars,
check ebay. The local oscillator is at 9750 MHz, so to receive the start of
the pass band at 10489.55 MHz the SDR should be tuned to 739.55 MHz, most
SDR's should be capable of that. The pass band is a little bit below the
spec of the LNB which starts at 10700 MHz, but according to the
measurements done on the oe7forum linked below the -3 dB point of the LNB
is at 10048 MHz, so it should work just fine.

See also:
 - Octagon LNB spec:
http://www.oe7forum.at/download/file.php?id=1363&mode=view
 - Octagon LNB test: http://www.g4jnt.com/pll_lnb_tests.pdf
 - Description of a 10 GHz ground station (in german unfortunately, but the
pictures say a lot) http://dl3jin.de/10ghz_rx.htm
 - There is a lot of activity in Austria, maybe because satellite operation
with the current flock of birds is difficult when your horizon starts at 30
degrees elevation. :) http://www.oe7forum.at/viewtopic.php?f=42&t=468

For the uplink it's going to be something like a 70cm SSB-capable set, a 13
cm transverter, a PA if really necessary (but hopefully not when the
antenna gain and transverter output are high enough), all still to be
acquired.. The antenna is going to be a helical feed in the same dish as
the LNB, or maybe something like this, I'm not sure yet:
 - Quad helix array (sorry, german again): http://dl3jin.de/13cm_helix.htm

73,
Rico PA3RVG


On Tue, May 31, 2016 at 2:12 AM, Stan, W1LE <stanw1le at verizon.net> wrote:

> Hello The Net,
>
> What are other folks planning to use on the uplink 2400 MHz and the down
> link at 10,489 MHz, for the narrowband linear transponder ?
>
> Stab, W1LE    Cape Cod   FN41sr
>
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