Is this the reason for the move to UHF? Back when I lived in the city I never really saw much/any 'ghosting' on UHF stations, but horrible ghosting on some VHF (all the transmitters were within a couple miles of each other, so it wasn't an issue of transmitter/receiver site). Seems like if the signal is significantly more Fresnel sensitive, UHF would be a logical choice.
I still don't understand the 'upgrade' for terrestrial HD. What should have happened was a push to satellite. There's plenty of spectrum and space in the Clark belt, and its easier to get a solid signal waving around a 18" Directv dish than it is to try to 'dx' in some HDTV in most circumstances (most RVers and truckers I know can peak-aim a single feed directv/dishnet dish in under 2 minutes) JS > -----Original Message----- > From: [email protected] [mailto:Repeater- > [email protected]] On Behalf Of Chuck Kelsey > Sent: Monday, February 23, 2009 9:38 AM > To: [email protected] > Subject: Re: [Repeater-Builder] Somewhat OT - How to make HDTV *really* > work > > Dynamic multipath interference, in which the delay and magnitude of > reflections are rapidly changing, is particularly problematic for > digital > reception. While this just produces moving and changing ghost images > for > analog TV, it can render a digital signal impossible to decode. The > 8VSB-based standards in use in North American ATSC broadcasts are > particularly vulnerable to problems from dynamic multipath; this has > the > potential to severely limit mobile or portable use of digital > television > receivers. Solving the problem might require that different standards > be > adopted for mobile use. > > Chuck > > > > ----- Original Message ----- > From: "wd8chl" <[email protected]> > To: <[email protected]> > Sent: Monday, February 23, 2009 9:10 AM > Subject: Re: [Repeater-Builder] Somewhat OT - How to make HDTV *really* > work > > > > JOHN MACKEY wrote: > >> If the digital is on a very different frequency, then the frequency > >> change is a reason why digital reception may be problematic. For > >> example, if you are using a VHF antenna to try to receive > >> a UHF digital signal, that will be problematic. > > > > I should be able to use any normal TV antenna. If it works on analog > Ch > > 7, for instance, it should work on digital ch 7. Period. If it > doesn't, > > there is something inherently wrong with the medium. > > Again, RF is RF. The antenna doesn't care how it's modulated. > > > > > > > > ------------------------------------ > > > > > > > > Yahoo! Groups Links > > > > > > > > > > ------------------------------------ > > > > Yahoo! Groups Links > > >
