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Re: FO29/RS13 compared to UO14 - Why?



jim wrote:

> My question is why do I get such fantastic reception of UO14, but FO29
> signals are down in the static most of the time.  Does UO14 have
> considerably more power? both satellites are  leo. Both satellites use 70 cm
> for the downlink. They do use different modulation methods but would that be
> a problem?

It's not a "problem," just a different way of working out the compromises of
building a communications satellite.  The FM satellite uses all of its output
power to downlink one very strong signal which allows one user at a time to be
heard on a hand held anywhere in the footprint.  The linear transponder
satellites, such as FO-29 when in the analog mode, distributes its output power
across the passband, allowing dozens of users simultaneously to share the
resource, but by sharing they pay the price of weaker individual downlink
signals which requires greater sensitivity at receiving stations.  This is why a
good preamp mounted at the downlink antenna is so helpful when receiving analog
satellites.
--
Mark D. Johns, Cedar Falls, Iowa -- K0MDJ (EN32sm)
              http://pages.cfu.net/~mjohns/index.html
 "Heaven goes by favour.  If it went by merit, you would
    stay out and your dog would go in." -- Mark Twain


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