[amsat-bb] PSAT2 status (GREAT NEWS!)

[Scott]

Glad to hear all the positive news, Bob!  Thanks for keeping everyone
informed.

Regarding TLE, how sure are we that PSAT-2 is Object 44357 as indicated in:

https://www.celestrak.com/NORAD/elements/tle-new.txt

... at the suggestion of JA0CAW, a very accomplished amateur in Japan, on
tonight's passes I attempted to determine whether PSAT-2's downlinks on
145.825 & 435.350 might be stronger by tracking Object 44355 (2019-036S).
And, while you can't reach any conclusion from only two passes (nor at such
low elevations), by eye & ear the downlinks seemed stronger when tracking
44355.

Of course, any number of factors could skew my result and tonight's
observation was subjective at best.  But I wanted to put this on the
mailing list in case anyone else would like to do any similar tests.

FYI, just like last night I saw short snippets of PSK31 streams around the
280Hz & 375Hz marks but unfortunately still no sign of my 10m PSK31
uplink.  I also got a few seconds of clear SSTV audio again tonight.  The
70cm downlink is looking great!  Just need a little more elevation for my
modest setup and location (Virginia).

Thanks!

-Scott,  K4KDR

===================

On Mon, Jul 1, 2019 at 9:03 PM Robert Bruninga via AMSAT-BB <
amsat-bb at amsat.org> wrote:

> PSAT2 is doing great!
>
> PSK31 and SSTV transponder  have been on since launch.
>
> SSTV downlinks are looking good.
>
> See Gallery:  http://www.urel.feec.vutbr.cz/esl/psat2/sstv/
>
> Still waiting for first report of user PSK31 contacts.
>
> But I have not said much about the VHF modes… because we have had
> difficulty commanding.  This is because the PSAT2 VHF uplink uses an
> inexpensive narrowband XCVR module which is intolerant of overdeviated
> signals, exactly what you get with +/- 3 kHz of Doppler.
>
> ANYWAY, we can now consistently command if we set the Kenwood to narrowband
> NFM and do it right in the middle of the pass.  Plus, we can extend that a
> bit  (1.25 KHz after center) by then changing the radio step size to 6.25
> Khz where the channel raster ups the channel by 1.25 KHz).
>
> So, we now have command again!  You may have seen that we have turned on
> Sun vector S#... telemetry and can easily see by plotting the 1 minute xyz
> xyz xyz vector triplets that it is smoothly tumbling at about 1.3 RPM for
> nice battery charging and good thermal management.
>
> The downlink is live on FINDU:
>
> http://www.findu.com/cgi-bin/raw.cgi?call=psat2-1&time=1
>
> Background:
>
> This last 6 days of crisis was complicated by the fact that I am operating
> in a temporary dungeon while the building is being renovated and all my  27
> years of lab stuff is in 200 boxes surrounding me.  I installed a temporary
> ground station on the top floor and modest antennas and a TV rotator and
> the contractor let me drill a hole through the wall that they can seal up
> later.  But the big problem is the 8 flights of stairs from my PC and
> internet connectivity  in the dungeon up to the radio 6 times a day for
> passes with only a few hours sleep and all kinds of what-if-dead-ends.  And
> with passes from 10 PM to 2 AM.
>
> But we are back in the saddle again!
>
> And this good news reprieve is only an hour old, so it will take a while to
> decide what we want to do next.  In any case, the Brno University PSK31 and
> SSTV transponder has all the power for now, so enjoy.
>
> Uplink USB on 29.4815 and downlink on 435.350 +/- Doppler.  The transponder
> only comes up if there is a user in the uplink with PSK31.
>
> Bob, WB4APR
>