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

[Ka9p at aol.com]

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 at 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 at 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"
> 
>  ========================
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>  http://ludens.cl
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