[opendtv] Re: DTT tuner design
- From: "johnwillkie" <johnwillkie@xxxxxxxxxxxxx>
- To: <opendtv@xxxxxxxxxxxxx>
- Date: Sun, 8 Jul 2007 15:31:46 -0700
It\s been a few decades since I had to think much of this, but the dishes
have a HPBW about twice (thrice?) that of the horns and the latter have much
less side lobe issues.
John Willkie
_____
De: opendtv-bounce@xxxxxxxxxxxxx [mailto:opendtv-bounce@xxxxxxxxxxxxx] En
nombre de Dale Kelly
Enviado el: Sunday, July 08, 2007 12:57 PM
Para: opendtv@xxxxxxxxxxxxx
Asunto: [opendtv] Re: DTT tuner design
That's as I saw them when inspecting those sites. Twelve foot high
efficiency dishes per tower and using both space and frequency diversity, a
very major investment per site. Some sites did use very large horn type
antennas across the Sierras and there were likely others. I don't know the
selection criteria but I assume they are a higher performance antenna.
-----Original Message-----
From: opendtv-bounce@xxxxxxxxxxxxx [mailto:opendtv-bounce@xxxxxxxxxxxxx]On
Behalf Of johnwillkie
Sent: Saturday, July 07, 2007 11:15 PM
To: opendtv@xxxxxxxxxxxxx
Subject: [opendtv] Re: DTT tuner design
And, having spent many, many hours looking at cc and ofs microwave station
records (original, master, in paper), in many instances, space diversity
required three 12" tx and rx antennae on each tower, with two and sometimes
three frequencies per tx point, and multiple routing across the country
because in some locations, sometimes NOTHING worked for short periods.
And, I should point out, they usually had very generous noise and RF
budgets.
John Willkie
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