[amsat-bb] Re: P3E Microwave Frequencies

i8cvs domenico.i8cvs at tin.it
Sun May 11 14:47:20 PDT 2008

----- Original Message -----
From: "Jari Koivurinne" <jari.koivurinne at aina.net>
To: "Stan" <stan at capecod.com>; <amsat-bb at amsat.org>
Sent: Sunday, May 11, 2008 9:16 PM
Subject: [amsat-bb] Re: P3E Microwave Frequencies

> Hello!
> The X band downlink is centered at 10,451 MHz, the bandwidth is 38kHz.
> There will be a BPSK-beacon at 10,451,030MHz ie. just above the passband.
> The beacon is adjusted 6dB lower than the maximum pep of the linear
> transponder for easy uplink level adjustment.
> S band uplink is 2,439,000 Mhz for 10,450,9992 MHz downlink to be exact.
> Maybe we can tweak the last 800 Hz upwards ;-)
> This is for the S/X-mode and S band uplink in general.
> Sorry for those old frequencies that still exists on P3E websites and old
> proposals.
> 73
> Jari, OH3UW, S/X-P3E/P5A-team

Hi Jary, OH3UW and S/X-P3E/P5E- team

I am very happy for the X band downlink centered at 10451 MHz and I
tank you very much for it because I can use the same downconverter
10450-10452 MHz with a 60 cm dish that I have built for AO40 long
time ago before AO40 was launched  and never used for it but still
waiting for the future over the roof.

I am less happy for the S band uplink centered at 2439.000 MHz because
for AO40 I have built a transverter for 2400-2402 MHz with a 10 watt
linear amplifier that I used extensively for downlink on AO40 but only one
time for the uplink in mode S/K to demostrate in a scheduled test that the
onboard S-band receiver was efficient.

By the way I know that the primary purposes to change the old S band
uplink frequency choosen for AO40 is to test with P3-E the S/X band
transponder for P5-A in a fixed  selected pair of frequencies to get a
coherent mode so that if we want to save 10451.000 MHz for downlink
then 2439.000 MHz for the uplink is mandatory for you in order to use
two syncronized high power  2450.000 MHz magnetrons designed for
microwave oven.

If the S/X transponder with 38 kHz BW will be used extensively in linear
mode for the amateur use on P3-E only then I will build a new transmit
converter for 2439.000 MHz and a new linear amplifier for it.

Best 73" to you and to the S/X-P3E/P5A-team

de   i8CVS Domenico

> > Hello The Net:
> >
> > Was just at the    WWW.KEPS.IT   website and saw a proposed frequency
> > plan for P3E.
> >
> > I am starting to plan for Microwave receive only down converters and
> > transmit only up converters.
> >
> > How firm is the frequency for the X band downlink at 10,490 MHz  ?
> >
> > Ditto for the L2 uplink of 1,263 MHz  and S band uplink at 2,447 MHz ?
> >
> -----
> > Stan, W1LE   FN41sr   Cape Cod
> >
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