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

David - KG4ZLB kg4zlb at googlemail.com
Tue Oct 13 13:53:16 PDT 2009

Perhaps these could be translated into Spanish!


Eric Knaps, ON4HF wrote:
> 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
>      reception.
>   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.
> 73,
> ON4HF.
> Eric Knaps
> Waterstraat 30
> B-3980 Tessenderlo
> Belgium
> Tel. +32472985876 (mobile)
> http://www.on4hf.be
> Gary Lockhart schreef:
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