[opendtv] Re: News: Free but Fickle, DTV Eludes Some
- From: "Allen Le Roy Limberg" <allimberg@xxxxxxxxxxxx>
- To: <opendtv@xxxxxxxxxxxxx>
- Date: Sat, 7 Mar 2009 13:01:11 -0500
Here in Suncoast Florida our reception of DTV with fancy rabbit ears and no
wideband amplifier is substantially more satisfactory than NTSC was. This is
so with both Zenith and Magnavox set-top converters. We live on a mountain
top 22' above sea level in Port Charlotte, so our terrain is favorable.
I suggest solving the Cliff effect by having him move to Southwest Florida
while you can still buy a good house for $100K. We also have very little
snow, though daytime temperatures can dip as low as the high 60's. Our
summers are probably a little cooler than where he lives, too, but more
rainy in the late afternoon.
Al
----- Original Message -----
From: "Albert Manfredi" <albert.e.manfredi@xxxxxxxxxx>
To: <opendtv@xxxxxxxxxxxxx>
Sent: Thursday, March 05, 2009 9:48 PM
Subject: [opendtv] Re: News: Free but Fickle, DTV Eludes Some
>
> Craig Birkmaier posted:
>
> > Free but Fickle, DTV Eludes Some
> >
> http://www.tvnewsday.com/articles/2009/03/03/daily.2/
>
> The article says, among other things:
>
> "The dirty little secret about digital is that it doesn't have nearly the
coverage of analog."
>
> The real truth is, most of these articles don't educate or elucidate, they
go for dramatic effect.
>
> Sometimes the reception problems are explained by people expecting
VHF-only antennas to work for UHF too. Sometimes the problem is that the DTV
station is at still too low power. I'll bet that many times, the problem is
that the "successful" analog reception was very poor, but the interviewee
was never explained about the digital cliff. Rarely are all the facts given,
and this article is no exception.
>
> I did a tvfools.com experiment, to see what this one tool says about
analog vs digital signal strength for stations that are good or marginal.
>
> The analog signals that these interviewees usually rave about are most
likely local VHF stations. In my case, using my current antenna height of
~3':
>
> analog VHF digital (all UHF)
> ---------- -------
> Ch 4 -33.3 dBm -64.2 dBm
> Ch 5 -37.0 dBm -65.7 dBm
> Ch 7 -39.8 dBm -66.8 dBm
> Ch 9 -41 dBm -61.1 dBm
>
> Hmmm. You think 30 dB difference in signal strength could have some
effect? And yet, those DTV stations are good.
>
> So then I tried to see what a truly grainy and inadequate analog stations
would measure as, and compare it with its digital counterpart. Here are some
truly marginal analog stations, from Baltimore, and the comparative digital
strength. The digital is most often fine, sometimes over the cliff.
>
> analog (UHF) digital (also UHF)
> ---------- -------
> Ch 45 -96.2 dBm -100.4 dBm
> Ch 54 -88.7 dBm -97.4 dBm
>
> Going by these numbers, it seems clear that the problem is not so much
"digital," but signal strength differences. And even then, those essentially
unviewable analog stations, 45 and 54, are often beat by their solid digital
counterpart, at lower strength.
>
> I'm think the tvfool numbers are best taken to show comparisons, not
absolute values. I doubt my receivers are really good to -100 dBm. And it is
remarkable that analog stations really can sync up at such low power levels.
But truly, I bet most of the differences in reception are explained by the
digital signal being quite a bit weaker than its analog precedent.
>
> Bert
>
> _________________________________________________________________
> Hotmail® is up to 70% faster. Now good news travels really fast.
> http://windowslive.com/online/hotmail?ocid=TXT_TAGLM_WL_HM_70faster_032009
>
> ----------------------------------------------------------------------
> You can UNSUBSCRIBE from the OpenDTV list in two ways:
>
> - Using the UNSUBSCRIBE command in your user configuration settings at
FreeLists.org
>
> - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word
unsubscribe in the subject line.
>
----------------------------------------------------------------------
You can UNSUBSCRIBE from the OpenDTV list in two ways:
- Using the UNSUBSCRIBE command in your user configuration settings at
FreeLists.org
- By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word
unsubscribe in the subject line.
Other related posts:
