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Re: Preimstar Dishes and ATV/Megabit packet



On Sun, 19 Dec 1999, James D. Mayfield wrote:

> Bob, my understanding is that they are still on the air for a few more
> months, DirecTV is in the process of switch the customers equipment over to
> DirecTV....

If I assume that this means that the Primestar dishes and  feeds will be
hitting the junk pile in the next year, then we gotta find a use.  

Here is a brain tease...?  Since we cannot legally transmit on 12.5 GHz,
what if one put up a 10.5 GHZ carrier and a 2.4 GHz ATV or T1 data stream
from the same central site.  These would mix at the receive site to give a
12.9 GHz signal right in the passband of the Primestar system.

Problem is,  Neither 2.4 GHz nor 10 GHz would pass thorough the LNB's
front end, but what if it were simple to "strap" across the first RF amp
and go direct to the mixer?  THis mod "might" be simple?

Problem 2.  But still, wouldnt the levels be too weak to "mix".  Doesnt
the mixer usually need about +7 dBm from the LO to get above the diode
threshold?  OR, is it an active mixer?  ANy non-linearity would give some
product at 12.9 Ghz?  How much level would be required?

Just brain-whacking here.  Still gotta be a way to use this hardware for
amateur radio without having to  do microwaave surgery...

OBJECTIVE is a 1 megabit per second Amateur radio data feed (think WEB
surfing amateur radio).  Remember, your URL requests can go BACK to the
central site using just standard 1200 Baud 2 meter packet!  So we arent
talking about microwave transmitters for the masses, just a single 1m bit
"server" per amateur radio community (And  everyone that can put up a
primestar dish line-of-site)...

de WB4APR, Bob


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