[amsat-bb] WD9EWK on the CAS-3 satellites this afternoon/evening

Patrick STODDARD (WD9EWK/VA7EWK) amsat-bb at wd9ewk.net
Mon Sep 21 03:04:53 UTC 2015


After reading all of the fun everyone had last night and earlier today
working the new Chinese satellites, I was looking forward to the passes
late in this afternoon. The first of the two passes was not very high
out here in Arizona, with maximum elevation of 10 degrees around 0000
UTC. The next pass, about 90 minutes later, was up to a maximum elevation
of 47 degrees. I have been using my SDRplay receiver to work other
satellites, and I wanted to give it a try on these satellites. SDR makes
working these satellites fun, being able to see all of them on the

For the first of the two passes, around 0000 UTC, I had my SDRplay in the
yard, along with my 8-inch HP Stream 8 tablet and Elk log periodic. I did
not intend on transmitting during this pass, considering the relatively
low elevation. Once the satellites rose above the houses and hills to my
east, they were easy to hear. I could hear the CW telemetry from all 6
(CAS-3A through -3F), see the digital telemetry from all 6, and heard
QSOs on the transponders of CAS-3E and CAS-3F. While I was listening, I
used the HDSDR software's RF recoding function to capture all of this.
For about 5 minutes, I ended up with a 1.2 GB file.

After hearing the activity on that pass, I made sure I was all set to work
stations on the pass around 0130 UTC. I brought out one of my FT-817NDs,
my headset/mic, diplexer, and additional coax. I had my tablet all set with
the SDRplay plugged in and HDSDR on the screen. I made adjustments to HDSDR
so I could see and hear all 6 satellites, which fit comfortably in a 600
kHz bandwidth. Once I started seeing traces of signals on the HDSDR screen,
I started my RF recording in HDSDR and my Sony audio recorder (I still use
the external audio recorder, even when working with my SDR setup, as
insurance in case something happens to the HDSDR recording). And it was a
busy pass.

I saw activity appearing on both of the working transponders. Initially,
there was more activity on CAS-3F's transponder, but more activity showed
up on CAS-3E's transponder later in the pass. I started working CAS-3F,
and was able to log 3 QSOs - Brad KG7NXH a few miles southeast of me,
Glenn AA5PK in Texas, and Mike WA6ARA in California. At this point, it was
just after the midpoint of the pass, and tuned my FT-817ND and HDSDR to the
CAS-3E transponder. I heard WA6ARA CQing, and made a quick QSO with him for
my first CAS-3E QSO. I still saw more activity on CAS-3F toward the end of
the pass than on CAS-3E, but there were stations on both transponders.

Afterwards, I opened up the RF recording from the later pass, and saw that
I received the CW beacon and digital telemetry from all 6 satellites - just
like I saw on the earlier pass. I intend on posting both RF recordings,
but that might have to wait until tomorrow. The RF recording from the later
pass was about 1.9 GB for 9 minutes. I'll post a follow-up message here
when those files are available online, if anyone wants to grab a copy and
see/hear themselves as I heard the transponders out here in Arizona.

I could have worked these passes with my two FT-817NDs, but this is most
definitely one advantage for using an SDR receiver. I did not have to hear
anything on the transponders to know there was activity. I could see it on
the waterfall, and see the other signals from all 6 satellites. I could
tell which transponder was busier (CAS-3F was usually the busier of the
two). I also found that having HDSDR put the RF recordings on the tablet's
C: drive (internal storage) instead of the D: drive (micro-SD card) worked
a lot smoother.

I will also post details on my HDSDR setup with the SDRplay receiver. I
just bought this receiver a couple of months ago directly from its UK
manufacturer, but now they are available in the US from Ham Radio Outlet.
I still like the FUNcube Dongle Pro+, but that dongle only allows for a
maximum bandwidth of 192 kHz. This is fine when working one satellite, or
maybe a couple of these CAS-3 satellites, but the SDRplay allows for a
maximum bandwidth of 8 MHz. I'm only using 600 kHz bandwidth with these
satellites, so that my recordings don't overwhelm the tablet's C: drive.


Twitter: @WD9EWK

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