[amsat-bb] Re: FM satellite operations again again over Europe

Eric Knaps, ON4HF eric.knaps at telenet.be
Tue Oct 13 11:24:15 PDT 2009

Hello all,
I found these nice rules from VK3JED:

 1. First and foremost is to listen before and while (if possible)
     transmitting, to ensure your transmissions don't drown out a weaker
     station who may be on the edge of a pass or running QRP. Satellites
     should be an alligator free zone. It is strongly recommended that you
     set your station up so you can monitor the downlink while
     transmitting, so you can hear how well you are accessing the satellite
     and whether you accidentally clobbered someone else. Similarly, if you
     can't hear the transponder, don't transmit. Do something else more
     productive, such as realign your receiving antenna to improve
  2. Be brief. Because the traffic levels can be quite high, contest style
     (callsign/signal report/next station) operation is the most
     appropriate for most situations. Many stations also exchange QTH and
     first names, which is OK if time permits. If transponder activity is
     low, you can have a brief chat, but the opportunities for this are
     becoming rare now.
  3. Take turns. If you've just worked a handful of stations, be polite and
     hand the transponder over to someone else so they can work a few.
     There may be an opportunity to call back in later during the pass and
     work some different stations as the satellite passes over different
     areas, and others will appreciate your courtesy.
  4. When calling, a simple announcement (e.g. "This is VK3JED listening
     SUNSAT" or even "VK3JED listening") will suffice, like it does on a
     terrestrial repeater. Anyone within transponder range will hear your
     call. A short CQ call ("CQ SUNSAT, this is VK3JED") is OK too. Long CQ
     calls waste transponder time and frustrate everyone listening. Save
     the long CQs for HF, where they're appropriate. Only call CQ when
     there's a distinct lack of activity, such as at the very start of a
     pass and sometimes late in the pass after everyone else has finished.
     A well placed CQ call late in a pass might alert someone ahead of the
     satellite that a pass has just commenced over their QTH.
  5. Wait your turn. If a QSO is in progress, wait until it finishes before
     putting in your call. Butting in too soon is rude and wastes precious
     transponder time as the stations involved in the QSO have to repeat
     themselves due to your QRM.
  6. Don't tune up! Believe it or not, there are stations who test their
     satellite access by dropping a carrier over the top of everyone and
     perhaps announcing "Hello hello". Simply putting out a call at the
     appropriate time will provide all the signal checks you need (and get
     you a worthwhile contact! :) ), without annoying everyone else on the
     transponder. If you're really that doubtful about your equipment,
     perhaps connect your dummy load, test in the shack and try again
     another day, rather than disrupting everyone else. If you just want to
     hear your voice, well a tape recorder or a pair of walkie talkies will
     do just as well...
  7. Reward good operation. If you're answering a call, why not reward the
     good operators and put the alligators last on your list of priorities.
     If all satellite users favour good operators, perhaps everyone will
     learn that good ops have the highest QSO rates and earn the most
     satellite awards. :-) Peer pressure is a powerful motivating force, as
     any teenager will know (but probably not admit to! :-) ).
  8. Use the minimum power necessary. While power levels are not critical
     on FM satellites (unlike linear transponders where an excessively
     strong signal can affect other QSOs on the transponder), using the
     minimum power necessary allows you to easier tell if you're 'doubling'
     with someone else. For the South African SUNSAT satellite, you
     shouldn't need more than 5 watts into a basic (1/2 wave handheld or
     turnstile) antenna, perhaps a bit more if the antenna is setup for
     terrestrial operation, to overcome radiation pattern limitations. As
     an example of good operation, recently one station who had multiple
     beams wound his power back to 20 mW. The signal into the bird was full
     quieting, but it was still possible to tell if someone else was
     underneath his signal. If he had run 100W, he couldn't have known if
     he'd stepped on anyone else, due to the capture effect of FM.

If everyone follows these simple guidelines (which are basically common
sense and courtesy), then FM satellite operation can be enjoyable for
everyone, regardless of whether you run a sophisticated satellite station
or a couple of handhelds from the back yard. FM satellite transponders are
like FM repeaters, only more extreme. On the positive side, they can enable
minimally equipped stations thousands of kilometres apart to communicate
with ease. On the other hand, the worst aspects of repeaters can be
experienced as well, such as congestion, doubling and even the odd idiot
dropping carriers! (I don't know how the idiots manage to always have a
very strong signal, even when the repeater is 800 km off the ground!). The
operators themselves (that's YOU!) have the power to determine what sort of
experience FM satellite operation will be in the future.


Eric Knaps
Waterstraat 30
B-3980 Tessenderlo

Tel. +32472985876 (mobile)


Gary Lockhart schreef:
> Thank you sharing some good operating practices that would make satellite ops in the US more enjoyable and equitable as well.
> 73, Gary AB3ID   
> *************************************************************************************
> Hi all in Europe,
> It is obviously about time to repeate a few 
> good points about operating via the FM repeater 
> satellites.
> 1. Do not transmit if you can not hear it
> 2. When the satellite is busy - limit the number of QSO's to ONE
> 3. Do not call over an ongoing QSO
> 4. A valid QSO just needs the call and the report
> 5. Give way to weak stations like /p and /m 
> 6. Allow DX-peditions to make as many QSO's as there are callers
> That was the short version :-)
> I have a long version in English, Italian, Russian, Spanish and French.
> I can send it to you if you want it. Could use a few other languages 
> like Greek, Polish and others.
> It would be nice if you can get it in your national journals.
> And please no flames !
> 73 OZ1MY
> Ib
> **************************************************************************************
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