Charlie Young wrote in a message to Bruce Legrande:
> and I can't think of a reason that it SHOULDN'T be poss-
> ible (with the proper hardware) to use a satellite in the
> same way as one would use a mountain top digipeater.
CY> Almost anything is possible.  The question is; why hasn't
CY> it happened yet?  Of course you could not use any existing
CY> geo satellite with Amateur Radio because none of them have
CY> Amateur frequency transponders.  The phase 3 satellite
CY> will be almost as good as a geosynchronous sat because
CY> of its highly eliptical orbit that will park it over
CY> North American for many hours at a time.  You are probably
CY> just using Amateur Radio as an example, right?
Actually, I wasn't thinking about using the Amateur freqs for the uplink.  I 
was more refering to Amateur Radio as a topic for programming content.  I 
don't think I made that clear,
as I was rambling a bit...  The uplink would HAVE to be on
the accepted frequencies of the audio channels (for the data) and the video 
freqs for the visual programming.
Even the "Phase III" sat - as I understand it - would need
to be accessed by an array capable of tracking it's path.
This means MUCHO EXPENSE as far as equipment goes, not
only for the steering on the dish but also the controller
to aim it and keep it sync'd.
I was trying to figure a way that the average person would
be able to afford to do this, shy of having RACKS of hardware.
> What would be involved in building
> a microwave transmitter (or better yet, a tranceiver) that
> would be 'rockbound' on maybe one or two frequency pairs
> so the average public earth station could have uplink
> capability as well ?
CY> There are already systems similar to what you describe
CY> that have been operating on Ku-band for many years.
CY> They are not crystal controlled one-frequency transmitters
CY> though.  They are synthesized "network controlled" similar
CY> to cell phones.  The network instructs each transmitter
CY> to switch to a certain frequency (channel).  The transmitter is
CY> disabled when not receiving the control signal so that it cannot
CY> transmit on the wrong satellite.
Here we go again with the high co$t...  I don't know about you, but I don't 
think the average person (incl myself) would be able obtain that type of 
'cutting edge' hardware.
>  With the speed of 19200kbps digital
> (which I understand is actually becoming comparativly slow)
> and the packetizing protocol that would allow many connects
> on one frequency via rotational sharing, I would think that
> quite a large number of stations could be served from one
> transponder on the audio frequencies.
CY> Many of the radio networks use satellites
CY> for transmitting their signals to local broadcast
CY> stations.  The uplinks require larger
CY> dishes than 10 feet on C-band.  What you are talking
CY> about would have to be done on Ku-band or higher.
I don't understand...  When I was an uplink station
'shift operator', we transmitted on the C-Band to the
sats and the dish we used was not much larger (maybe 15' dia) than what I 
have sitting behind the house now for C-Band recv.
The main difference was that the transmit parabola we used
at the radio network was solid fiberglass (not mesh).
Sincerely,
           Bruce - kb6lwn - ck1@pacbell.net
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