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
> occasional 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"
>
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> http://ludens.cl
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