Archived from groups: alt.tv.tech.hdtv (
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Harry wrote:
> Is Silver Sensor also a good analog antenna?
Harry, to summarize:
The Silver Sensor is a UHF antenna. It gets channels like "25" and
"56" quite well. The Silver Sensor is a lousy VHF antenna. It does
not pick up channels like "4" and "7" well at all.
Detail:
For years, US broadcasters have been sending signals using a standard
called NTSC; this is probably what you are thinking of when you write
"analog." The newer ATSC "digital" television standard is a digital
signal being carried on an analog channel.
Let's say you're George Bush and you want to put up an antenna in your
eastern home. NBC is on channel 4, but the digital NBC channel is on
channel 48. (That is, what you are likely thinking of as "analog" NBC
- the NTSC broadcast of the Washington, DC NBC affiliate - is on
channel 4 and the ATSC "digital" broadcast is on channel 48.)
Likewise, CBS is on 9, but the digital CBS channel is on 34. Because
the digital channels have to go (for now) on unused slots, they tend
to be on UHF channels (14-69) rather than VHF channels (2-13) because
VHF has been crowded for years.
So, the Silver Sensor is a UHF antenna but gets advertised as a
"digital TV" or "HDTV antenna" because most of the digital signals are
being sent on UHF (14-69) channels.
Now, in some cases, a VHF channel was available to carry the digital
signal. Examples are CBS digital on channel 3 in Chicago and NBC
digital on channel 12 in San Jose. In that case, the Silver Sensor
"HDTV Antenna" won't do you a heck of a lot of good getting the HDTV
signal because it's a UHF antenna and the digital signal is on a VHF
channel.
Confused? Gets worse. George goes up on the roof and points his
antenna away from the Capitol Building, because the TV towers are in
the other direction. Well, the TV towers for NBC, CBS, ABC and UPN
are in the other direction. WETA (the PBS station in Washington that
people outside of Washington know) is in a different direction and the
WB affiliate is in yet another direction. Don't get George started on
multipath and all the tall buildings. Or how he needs to point his
antenna in different directions to get a picture from different
channels coming from the same tower. Or how all the digital signals
may get switched over to the VHF (2-13) channels in several years when
US TV broadcasts go all digital.
Well, the last point isn't a big deal - George will have a new address
by then.