[Amps] VHF all-mode and DC-to-daylight rigs

[Manfred Mornhinweg]

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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