Audio Captured from this event by AJ3U:
Pass 1: 0850 EDT - [MP3 -
600KB][WAV - 1.84MB]
Pass 2: 1026 EDT - [MP3 -
440KB][WAV -
1.36MB]
These clips aren't super - mostly static with occasional packet bursts,
but a
couple of
voice transmissions can be heard. Most of the audio problem was on my
end. I don't have
the rotator up on the tower right now, so I set it up temporarily on
the ground on a tripod this morning. Without the antennas up on the
tower, I was receiving through trees for most of the pass which really
attenuated the signal.
Explanation of event by Bob Bruninga, WB4APR
This Thursday, 29 Sept on two morning passes over
the Eastern USA, Naval Academy students will
attempt a special experiment via PCSAT2.
They will watch for APRS or UI packets heard via
the PCSAT2 145.825 uplink and will QSL those
packets by VOICE on the 437.975 downlink. The
two passes involved will be 0850 EDT and 1026 EDT.
Users who want to participate should transmit
their packets on 145.825 VIA ARISS, and although
your packets will be digipeated on the 435.275
downlink, the fun will be to see if the midshipmen
can speak to you in response on 437.975 FM voice.
To minimize interference, just during these passes,
the normal ARISS packet system on 145.800/145.99
will be temporarily disabled. This is a new un-tried
experiment, so there are no guarantees of success,
but we thought it would be fun to give it a try.
PCSAT2 Command Team
WB4APR
Followup e-mail from WB4APR after the event:
Thanks Luc and everyone else that played with us this
morning. As you can imagine Murphy was visiting both
classes. On the first pass, a single error led to
us spending the entire pass trying to figure out
why the Transponder was not being commanded on.
(even though it was on) So therefore we were not
simultaneoulsy watching the packet downlink for users.
On the second pass, things worked, and we saw
these calls: WA1KAT, K1ICO, AJ3U, W8AAS...
(plus Luc at 9600) and one other call. A student
walked off with the log so I'm not sure right now.
>Even with ARISS packet OFF i was hearing packet
>burst at 437.975
Yes, our FM donwlink shares the transmitter with
our side B command system so those were command
and telemetry packets.
The scenario here was that we had two classes
of about 16 students each who had never seen
PCSAT2 before. I got to give them a 30 minute
power point description and then I got 8 volunteers
to man these stations:
1) Command station (actually that was me)
2) Telemetry receiver & display
3) Instant-Track and antenna controlller
4) Instant-track and voice antenna controller
5) Voice operator, also looking at packet screen
6) Voice receiver operator tracking doppler on 437.975
7) Internet montitor watching the FINDU web pages
8) APRS display monitor
We got them to the ground station with 5 minutes to
get familiar with their station. ANd then the pass
began. Of course lots of prior planning could do
this better, but we dont have that luxury at an
academy where every hour of the day they are
assigned
other things. So we have to do the entire
PCSAT2 lecture and demo in one single class room
period.
THe pass 1 problem turned out to simply be the
volume on the Voice monitor downlink receiver
(a TS-2000 with 65 front panel controls) was
on zero. (My fault because I left it that way after
last nights test). I had only trained that student
to tune Doppler, never mentioned volume.
Now, because I was not hearing audio on the downlink,
I paniced and assumed it was the command link, and
so wasted the rest of the pass trying to re-connect
to both the A and B sides and try the varous alternate
command capabilities. (Apparently it was working
all along. But since we had no feedback, the voice
operator basically said nothing.
On the second pass, it worked fine. But this was a
completely new class and they had even less time
to prepare. I was disappointed at the audio level.
It sounded great when I tried it earlier, but seemd
very low modulation. Maybe the student was not
speaking well into the mic, though it did look like he
was holding it correctly.
I played back the audio files that AJ3U recorded
and there was hardly anything to hear. By the
way, we were only using an omni for our uplink
so that explains our less than full quieting signal.
But we did hear more than what his recording
captured. And another station said he heard it
great through the whole pass.
>Better luck next time
Yes, always lessons learned. And it is so easy to
do when one is all alone in the shack. It is so
hard to do while trying to get 16 people involved.
Oh, the other lesson is to REBOOT all PC's prior
to the event. The packet display laptop for the
voice operator position was looking just great.
But dead as a post.
Bob, WB4APR
USNA Satellite Lab