UHF is more robust than VHF (was Re: Digital TV receptionproblem)
Garrett Wollman
wollman@bimajority.org
Sat Jun 20 22:54:21 EDT 2009
<<On Sat, 20 Jun 2009 22:07:09 -0400, "Dan.Strassberg" <dan.strassberg@att.net> said:
> I read that WHDH has applied to double its ERP on Channel 7
> (presumably by diplexing its main and about-to-be-installed
> auxiliary VHF DTV transmitters).
They might be thinking about doing so, but they have not applied to do
so yet.
The channel 7 transmitter they have now can do at least 4 kW TPO (I
can't find the actual specs on the Harris Web site), so I'd expect
them to try increasing that first. The existing antenna does about
9.6 dB.
> haven't heard that analog power was peak and digital is average, so
> it doesn't necessarily follow at all that 60 kW digital is less than
> 300 kW analog." Does anybody have a conversion formula?
Multiply by 5 is the rule of thumb; I'm not sure how accurate it is,
or why the FCC didn't apply it in setting the power limits for VHF.
I can't seem to find where in the rules the power limits are actually
defined. I know I've read them in some official source (maybe one of
the DTV Reports).
-GAWollman
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