Wouldn't that be equivallent to 'ghosting' on analog TV? Wouldn't directional antennas be better for that reason?
Joe M. Hap Griffin wrote: > > ----- Original Message ----- > From: "mch" <[EMAIL PROTECTED]> > To: <[email protected]> > Sent: Tuesday, December 20, 2005 7:48 PM > Subject: Re: [Repeater-Builder] hdtv radio shack ant ???? > > > You know, this subject (mail subject line) reminds me of the stories I > > was told about them coming out with antennas for *COLOR* TV that were > > interpreted to be different from B&W TV antennas. Supposedly, for color > > TV you needed a Color TV antenna. > > > > B&W TV, Color TV, HDTV... they ALL use the same frequencies and the same > > antennas would work equally well. > > > > Joe M. > > > > Yes, that is true, to a point. The 8VSB modulation used by DTV is prone to > multipath interference. This is easily seen with a spectrum analyzer when > turning an antenna...multipath will show up as a notch (or multiple notches) > in what is supposed to be a flat noise-like energy spectrum form the DTV > transmitter. Depending on where the notch is in the spectrum and its depth, > the digital decoder and loose lock on the signal with the result being the > dreaded blue TV screen. Thus, the best DTV performance is from antennas > that are more directional which reject any off-axis multipath signals > better. Multipath is why indoor antenna reception of DTV is so touchy. > However, the later generations of tuner chipsets are getting much better at > multipath compensation. > > Hap Griffin > VP-Engineering > SCETV > > > Yahoo! Groups Links > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
