Last satellite post, I promise, unless it really is about an amp, but the
AMSAT status page located at http://www.amsat.org/status/ shows the most
recent telemetry reports from around the world for all ham satellites.
This AM, for example, showed 5 Chinese XW sats, FO-29, AO-73 and AO-7 as
having active linear transponders. Yeah, the passes are short, but you do
hear a few rag chews among regulars.....
73 Scott
In a message dated 1/7/2017 10:07:31 A.M. Central Standard Time,
amps@contesting.com writes:
Interesting topic, maybe a bit off topic, but very informative. Guess I
should see what I could kludge up in the way of a cross polarized antenna
for VHF/UHF and do some listening. I would bet that Google would be my
friend in searching for satellites over South Texas. Hadn't really thought
about satellites in many years.
John WD5ENU
Sent from my iPad
> On Jan 7, 2017, at 09:44, Manfred Mornhinweg <manfred@ludens.cl> wrote:
>
> Gerald, Scott,
>
>> The satellite is the moon of course. With current and free WSJT
>> software there is no need for the gigantic antennas that have been
>> used in the past.
>
> I have used WSJT, and at first it was quite impressive to see how it can
> dig information out of signals buried deep in the noise. But my interest
> quickly faded, for the same reason that I don't do DX in the usual way,
> nor take part in contests: I'm looking for meaningful communication! And
> that's not possible in WSJT. It just provides the minimal interchange
> required to have a "legally valid QSO". I'm not trying to fill my
> logbook with thousands of "contacts", nor to fill my walls with dozens
> of (purchased!) awards for having contacted so-and-so many stations from
> these-and-those places. What I'm looking for in ham radio is technically
> interesting things, and real communication. WSJT provides the former,
> but wears off quickly, and it definitely doesn't provide the latter.
>
>> Seems a bit wasteful of time and expense to implement any man made
satellite for amateur radio purposes considering the capability
>> already in place.
>
> It's a totally different thing. The best ham satellites, for me, were
the store-and-forward pacsats. There was a numerous worldwide community of
hams posting meaningful messages, stories, photos, software, etc, on those
sats. The moon definitely doesn't replace that! Nor does HF. And I regret to
say, but have to, that what does replace it best is the internet, rather
than any ham-owned, ham-developed or ham-operated system.
>
> And for meaningful DX QSOs, those in which something could be discussed
for some time, there is still no replacement for Phase 3 VHF/UHF
satellites. On AO-13 I could talk for an hour or two to someone far away,
about
interesting technical matters, since all people operating on the sats had at
least some technical knowledge. If I try that nowadays on 20 meters, firstly
its hard to find any ham interested in a technical conversation, and
secondly it doesn't take even two minutes before somebody "spots" me on a DX
cluster, and the next moment there is a pile-up of deaf prefix hunters calling
me without even hearing me, disrupting my ongoing QSO.
>
> As you can see, I miss the good old times of good old ham sats!
>
>> But where does the notion of no useable satellites come from?
>
> In part it comes from location, and for two reasons: One is that there
are no high orbit sats now, and that low orbit sats have a coverage circle
of about 2000km radius at most, and that there are very few sat-equipped ham
stations within that circle from my location. Instead over North America
or Europe there are hundreds, if not thousands, of ham sat stations within
that circle. And transponder/repeater sats are usable only if there is
someone to talk to, within the coverage! And the other reason is that the
owners
of several sats, starting in the late '90s, have opted for switching the
sats on only over densely ham-populated areas. Those sats will be on, and
transmitting on high power, often at a negative power budget (consuming
battery charge), over North America and Europe, and will be silent, recharging
their batteries, everywhere else. Some have been programmed to switch on
when over the northern hemisphere, and off when over the southern. So I never
get a chance to
even detect those sats, except when their clocks shift, they come on a bit
early, and I just hear them for a few seconds at the end of a north-going
pass!
>
> Instead the phase 3 sats could be accessed equally well from the
northern and southern hemispheres, so the field was even. This was not always
planned - there were sats that were intended to have Molniya orbits favoring
the northern hemisphere, but which failed and ended up in orbits giving about
equal chances to all!
>
> And the Pacsats of the first generation, both the Microsats and the
UoSats, were always on except during power shortages, and had orbits that
offered the exact same access in the northern and southern hemispheres. That,
combined with the fact that one didn't need another ham within the sat's
footprint, led to a boom in satellite operation among hams in the southern
hemisphere.
>
> > There
>> are at least 5 (+) reliable LEO linear transponder satellites, and
>> I've yet to listen to an orbit where there isn't activity.
>
> Could you list them? I would like to specifically search for them, and
see which ones are actually operating when over my area. The last time when
I spent several days collecting information from the web, then searching
for sats on UHF, VHF and 10 meters, was almost exactly one year ago. At that
time I heard Tigrisat (useless for hams), Bugsat-1 (also useless for hams),
FO-29 (VHF/UHF linear transponder, operating, but with no users),
Itupsat-1 (useless for hams), another Cubesat on 437485 from which I captured
just
a single packet (CQ>KD8SPS), and some very weak signals on 437420 or
437415, which I didn't manage to decode.
>
> All the other sats which according to various web sites are supposed to
be active, could not be heard here.
>
> This is with the same antenna, preamplifier and radio that I used in the
90's to work many sats, with signals up to S9+20. So I don't think my
station is deaf.
>
> I also made such surveys in previous years. The longer back we go in
time, the more active ham sats there were, coming to a peak in the 1990's. I
remember a time with 7 fully active pacsats, 2 poradically active ones, 2
high orbit sats, 2 low orbit analog transponder sats, two or three FM
repeater sats, plus a digitalker and several telemetry-only ones. That's just
counting VHF and UHF! There were additional signals on 10m, and a few sats had
some downlink in the 23cm band too.
>
> Five reliable sats with transponders, that would be great... Specially
if there actually was activity on them! If that turns out true, I would
return to some sat activity!
>
>> And the
>> old Yaesus have been fine for accessing them with half way decent
>> antennas, without preamps.
>
> On VHF a preamp really isn't very useful, indeed. But on UHF it helps a
lot. I have preamps on both bands, and when I use the 2m preamp I have to
put an attenuator at the radio's input, or it will overload on strong
repeater signals within the band. The minimum discernible signal with that
preamp
and attenuator combination is just about 1dB better than without. Band
noise is the limiting factor. But on UHF the band noise is way below the
cable+receiver's noise, so a good preamp at the antenna feedpoint helps by
several dB, and that's noticeable.
>
>> Granted it's not AO-13, but plenty of fun to be had - we had more
>> interest from younger, newer hams in our Field Day satellite station
>> than just about any other thing.
>
> I can imagine. The problem is likely that somebody who has operated a
lot on the phase 3 sats and the pacsats in the heydays of the 1990's, running
a satnode and a satgate, isn't too interested nowadays in making a few
occasional 2-minute SSB contacts with a very few relatively local hams on an
analog transponder... Specially not when the other station lacks proper TX
and RX Doppler compensation, and has to be chased across the transponder!
>
>> And of course there still is a lot of ISS activity with schools etc,
>
> Again, location! Almost all that activity takes places over North
America, and some over a few other select places of the world, but hardly here
in
my area. And the ISS is in a very low orbit, so its coverage is even
smaller than that of a typical low orbit sat. When the ISS ran some
permanently
active ham system, such as a packet mailbox, I could use it, but the oc
casional activity with schools happens far beyond my radio horizon.
>
>> OK, satellite cheerleading over.
>
> Really we are getting "a little bit" off-topic... Sorry, folks! I will
try to behave! ;-)
>
> Manfred "past times were always better"
>
> ========================
> Visit my hobby homepage!
> http://ludens.cl
> ========================
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