[opendtv] Re: VHF vs UHF coverage

Bert, I was composing an answer to this when your reply came in; you took
the words out of my mouth!

IMO, you nailed it.
Thanks, Dale

-----Original Message-----
From: opendtv-bounce@xxxxxxxxxxxxx
[mailto:opendtv-bounce@xxxxxxxxxxxxx]On Behalf Of Albert Manfredi
Sent: Saturday, May 23, 2009 3:01 PM
To: opendtv@xxxxxxxxxxxxx
Subject: [opendtv] Re: VHF vs UHF coverage



Richard Hollandsworth wrote:

> NTSC power has always been measured and specified
> as PEAK power, whereas DTV power is always
> measured and specified as AVERAGE power.  Peak
> power for DTV is about 7 dB higher than average
> power.

I think you mean NTSC peak is 7 dB higher than NTSC average, yes? With
scrambling, DTV average and peak power should be virtually identical, I
think.

> DTV also has a performance advantage of about 5
> dB for a total of 12 dB.

I guess some people are skeptical about this extra 5 dB. Also, because
analog viewers can put up with a lot of visual "abuse," where digital
viewers have to contend with a cliff, I would err on the side of being more
forgiving with DTV signal margin.

I do totally agree with your point about UHF receive antenna gain vs VHF
antenna gain, however. It's just that propagation models do show a lot more
UHF falloff at the fringes, with low altitude receive antennas, etc.

Just 3 weeks and we'll know just how accurate those FCC predictions were for
VHF. My fingers are crossed.

Bert

_________________________________________________________________
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