[amsat-bb] LilacSat-2 over Central US 2340z
saguaroastro at cox.net
Wed Sep 23 04:30:46 UTC 2015
I saw the message about the FM transponder being on around the middle of the pass, by the time I got my gear out and set up on the VFO (frequencies now in memory) the bird was about 20 degree from LOS. Since I operate from the backyard of my North facing house, it was down near the rooftops. I did throw my call out, but did not hear the downlink. based on your report, I was probably too high. I won't be available tomorrow or Thursday to try again, maybe Friday. My Schedule is starting to ramp up with theater season....
As for the choice of uplink, Here in AZ 144.410mhz has become the defacto Fm simplex frequency for SOTA (Summits on the Air). So dredging up a discussion from a few weeks back about the choice of frequency, It appears that the IARU will not coordinate these frequencies, so does that mean these birds will not receive OSCAR numbers?
Rick Tejera (K7TEJ)
Saguaro Astronomy Club
Thunderbird Radio Club
SaguaroaAstro at cox.net
From: AMSAT-BB [mailto:amsat-bb-bounces at amsat.org] On Behalf Of Patrick STODDARD (WD9EWK/VA7EWK)
Sent: Tuesday, September 22, 2015 8:39 PM
To: amsat-bb at amsat.org
Subject: Re: [amsat-bb] LilacSat-2 over Central US 2340z
Thanks for the QSO on that pass, that started just after
0110 UTC. I was in a downpour in my back yard during the
last couple of minutes. Thankfully, thunder and lightning
stayed far enough away to be in the yard with my Elk. I
also heard KO6TZ and W7KKE, but they never returned calls
from either of us to make QSOs. I heard someone else near
the end of the pass, but I was having to shut down as I
tried to keep my radio from being swamped with rain. I went
with my Icom IC-2820H and Elk log periodic for this pass,
and I'm glad I did. HT power would not have been enough to
get through tonight, and that is a shame.
The uplink frequency appeared to be spot-on at 144.350 MHz.
Once I lined up the downlink, I didn't need to change my
uplink frequency, and did not have to go to narrow FM to
make it through the satellite. This frequency is an
unfortunate choice for an uplink, as it is not in a
recognized satellite subband in very many places. It is
in the "New OSCAR subband" according to the ARRL:
Even though ARRL has specified 144.300-144.500 MHz as
another satellite subband, many parts of the US go in a
different direction for this part of the 2m band, never
mind other parts of the world. The IARU regional band
plans say nothing about amateur satellite operating
around 144.350 MHz. Here in Arizona, the ARRL-specified
144.300-144.500 MHz OSCAR subband is observed (with
exceptions for APRS on 144.390 MHz and AM on 144.450
MHz), but I know I have heard AM and SSB activity around
there in the past. In neighboring southern California,
the 144.300-144.500 MHz subband is for FM simplex, with
the exception of 144.390 MHz for APRS. In the southeastern
US where SERA is the frequency coordinator, this subband
is for "multi-mode operation", with APRS specified for
144.390 MHz. In any event, the international radio
regulations - and, for that matter, FCC Part 97 here in
the US - permit amateur satellite operations anywhere in
the 144-146 MHz range, and this is probably what was
being considered in China for this and the other
satellites recently launched.
The downlink appeared to be low, possibly as much as 15 to
25 kHz below the nominal frequency published before the
launch. When I shut down my gear, I was down to 437.190
MHz to hear the satellite. AA5PK said his radio was down
to 437.191 MHz at that point. My IC-2820H only tunes in 5
kHz steps, so I didn't have the finer tuning as Glenn had.
The downlink was strong, much stronger than SO-50. This
should be a big help for those who never heard satellites
like AO-27, AO-51, or HO-68 with the stronger downlinks
they had a few years back.
For at least the last half of the pass, there was what
appeared to be a steady carrier on the 144.350 MHz uplink.
Glenn and I were able to overcome it, and - at least for
a moment or two - so were KO6TZ and W7KKE. W7KKE's audio
sounded a little on the low side, and I missed his call
in real time (Glenn didn't, and he called W7KKE without
success). I tried to overcome the carrier using the low
(5W) and mid (15W) power settings on my IC-2820H, and
those attempts failed. The high (50W) power setting was
the only one I could use to get through. If I had to
rely on the memories in the radio to work this satellite,
I'd prepare many more memories with the downlink frequency
going down to 437.190 MHz and possibly even 437.185 MHz.
Be ready for anything, where you may even have to go
higher on the downlink frequency, but definitely be ready
for it to go way below the published 437.225 MHz frequency.
Weather permitting, I hope to be on another pass tomorrow
evening around the same time (0100 UTC, if my prediction is
correct). I can't work the pass before this one, between
the low elevation on that pass and I'll still be at the
office at that time.
Just worked Patrick WD9EWK on Lilac-Sat-2 FM transponder. The downlink was
> initially close to 437.198.
> Heard KO6TZ and W7KKE calling, but evidently they had not yet found the
> downlink frequency.
> The downlink was exceptionally strong. SatPC32 tracked Doppler very well
> using object 40908 in the Keps. I was able to copy the bird to the horizon.
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