Right now, the Analog channels that I get solid and noise free seem to be
subject to fades on their UHF DTV counterpart. Makes me wonder how it will
goof up the market when I won't be able to go back to analog as a back-up
when the DTV goes down.
"J. Mc Laughlin" wrote in message
.. .
... and some stations will be transmitting DTV on a third channel (not the
present analog nor the present DTV channel)

I have also found that a number of stations have applied for changes (so
far
they seem to be ERP changes) to what is contained in the eighth FCC report
of March 2008. One needs to go to the FCC site and enter call sign of
each
station to find the present information.

A surprise to me is that the coverage contour for analog TV is 64 dBu and
for DTV is 41 dBu - a difference of 23 db. However, the reductions of ERP
do not seem to be that large. Stations that are now a bit weak may be
unusable after Feb. 2009.

73, Mac N8TT


J. McLaughlin; Michigan, USA
Home:
----- Original Message -----
From: "Ed_G"
Newsgroups: rec.radio.amateur.antenna
Sent: Sunday, September 14, 2008 8:27 PM
Subject: Chart of HDTV freqs?


Jeff Liebermann wrote in
:

snip

What is happening is that many TV stations have been assigned a
channel on which to broadcast their new DTV signal prior to Feb. 17,
2009 while at the same time remain broadcasting their NTSC video on
their original channel. The chart shows these two channel designations
in the first two channel columns, and in the last column it shows what
channel the TV station will end up on when Feb. 17 comes around. As
indicated, some stations will be moving their DTV broadcast from the
temporary channel assignment back to their original NTSC channel
assignment, and some stations will remain broadcasting the DTV signal
on the temporary channel, which becomes their new permanent channel.



Ed K7AAT

JB wrote:
Right now, the Analog channels that I get solid and noise free seem to be
subject to fades on their UHF DTV counterpart. Makes me wonder how it will
...
Ed K7AAT

Really? Something is quite wrong there!

Digital signals should require much less power to deliver the same
"quality" signal.

Indeed, digital is an upgrade to all existing systems. Listen to an
analog signal, then a digital signal--whether over hardwire (remember
the phone adds with the "dropping of a pin") or AM/SSB over RF ... can
you just imagine attempting an analog signal over a dial-up modem or
broadband? We would still be in the "internet stone-age!"

All that really does not take any thought at all ...

Regards,
JS

In article ,
John Smith wrote:

Really? Something is quite wrong there!

Digital signals should require much less power to deliver the same
"quality" signal.

JS-

Why do you say that?

You can't have a less-than perfect digital TV signal. There is no snow
because a weak digital signal's picture freezes or goes away. Therefore
there is no way to compare quality levels of less-than perfect pictures.

Most of the time my simple antenna picks up good HDTV. However there
are times when reception is poor, and I have to switch to the Analog
tuner. I'd rather have a little snow than no picture at all!

Fred

Look at the spectra of the signals an compare the levels. More amplitude in
the sync pulse and average video than the ATSC pilot across the board from
what I'm seeing. Perhaps they are trying to get away with less. Perhaps
fooling around with tower work and dropping the power. Hard to tell with
the GUI meter and never had the service monitor up at the time. One is DTV
VHF HI that is a new one with no Analog so I lose it completely and 2 are
UHF that are fading on me from time to time where I have to punch to the
Analog broadcast, one of which is VHF. Generally more power is needed on
UHF to come up with comparable range.

"Fred McKenzie" wrote in message
...
In article ,
John Smith wrote:

Really? Something is quite wrong there!

Digital signals should require much less power to deliver the same
"quality" signal.

JS-

Why do you say that?

You can't have a less-than perfect digital TV signal. There is no snow
because a weak digital signal's picture freezes or goes away. Therefore
there is no way to compare quality levels of less-than perfect pictures.

Most of the time my simple antenna picks up good HDTV. However there
are times when reception is poor, and I have to switch to the Analog
tuner. I'd rather have a little snow than no picture at all!

Fred

Fred McKenzie wrote:

...
Why do you say that?


Easy, with digital you are simply determining whether a signal is
present--or on (a binary one), on not--and off (a binary zero) ... an
analog signal contains much more data which can "screw up."

You can't have a less-than perfect digital TV signal. There is no snow
because a weak digital signal's picture freezes or goes away. Therefore
there is no way to compare quality levels of less-than perfect pictures.


Oh, yes you can, indeed, ever hear of "lossy data compaction?" It is
used for audio and video where not every bit/byte of data need to be
perfect--attempt that with an executable file and it fails ... the
program itself can "deduce" if the data is just "degraded" or is beyond
use and pass it along to the video/audio device or toss it as decided ...

Most of the time my simple antenna picks up good HDTV. However there
are times when reception is poor, and I have to switch to the Analog
tuner. I'd rather have a little snow than no picture at all!

As I say, something is wrong, and it may not be "all on your end", and
broadcast HDTV may need some upgrades to the software handling the
coding/decoding of the signals ... widespread usage, in the future, and
"fixes" along the way should provide a much improved system.

I have not had a chance to "experience" broadcast HDTV yet ... however,
the cable HDTV is much improved over old analog ...


Fred

John Smith wrote:

Fred McKenzie wrote:

Most of the time my simple antenna picks up good HDTV. However there
are times when reception is poor, and I have to switch to the Analog
tuner. I'd rather have a little snow than no picture at all!

As I say, something is wrong, and it may not be "all on your end", and
broadcast HDTV may need some upgrades to the software handling the
coding/decoding of the signals ... widespread usage, in the future, and
"fixes" along the way should provide a much improved system.

I experience the same phenomenon. My antenna is a UHF indoor bow tie dipole.
(All my HD channels are currently on UHF.) I am about 30 miles from the TV
tower which is at 1200'. My HDTV set can show signal bars like a cell phone.
Without moving the antenna or other surrounding objects, the signal will
sometimes slowly vary by one or two bars. If it goes down too far the
picture breaks up and quits. At other times the same station will give a
solid 3 or 4 bars.This happens on all channels. Perhaps atmospheric
movement? Lots of dust here in the desert. Any other ideas?

I have not had a chance to "experience" broadcast HDTV yet ...
however, the cable HDTV is much improved over old analog ...

I have cable HDTV on my other set in the family room. Surprisingly (to me)
the broadcast HDTV picture is superior in quality to the cable HDTV picture.
Perhaps Cox is using more compression to squeeze more channels in the line.

AJ Lake wrote:

...
I experience the same phenomenon. My antenna is a UHF indoor bow tie dipole.
(All my HD channels are currently on UHF.) I am about 30 miles from the TV
tower which is at 1200'. My HDTV set can show signal bars like a cell phone.
Without moving the antenna or other surrounding objects, the signal will
sometimes slowly vary by one or two bars. If it goes down too far the
picture breaks up and quits. At other times the same station will give a
solid 3 or 4 bars.This happens on all channels. Perhaps atmospheric
movement? Lots of dust here in the desert. Any other ideas?


Yes, ducting and "ghosting" of the signal(s) due to reflections, etc.--I
can see these as being a REAL problem. From your description(s), sounds
like "they" just took the exact-same
technology/encoding/decoding-schemes and implemented them onto broadcast
.... what works well with cable (a relatively "stable" signal NOT prone
to the effects stated above ...) may not work all that well with
broadcast ... sounds like some "upgrades" are already in order.

I have just assumed, up to this point, that the digital HDTV signal is
"packeted" ... however, unlike our broadband modems and satelite
internet, you cannot request for a corrupt packet to be "resent" to your
TV ... however, I am wondering if corrupt packets (or, seriously
degraded ones) are just being "tossed" rather than passed along to the
video/audio circuitry? Perhaps the software should assume that no
matter how degraded (or, at least seriously degraded packets) should be
passed on and the viewer be allowed to determine if it is of enough
worth, or not? It almost sounds like this would be preferable to
no-signal-at-all. But then your description of "the bars" beginning to
degrade would soon reach a point of "un-viewable signal" anyway?; so,
at this point, perhaps no-signal-at-all is preferable ... hmmm, I wonder?

I have not had a chance to "experience" broadcast HDTV yet ...
however, the cable HDTV is much improved over old analog ...

I have cable HDTV on my other set in the family room. Surprisingly (to me)
the broadcast HDTV picture is superior in quality to the cable HDTV picture.
Perhaps Cox is using more compression to squeeze more channels in the line.

Hmmmm, you have me all the more anxious to have HDTV implemented in my
area ... LOL!

Regards,
JS

The neat thing about going full digital? You no longer have any idea why
the signal breaks up. PERIOD. The Customer is no longer bothered by
interference of any kind. Either it works or not. If your QSO, Phone Call,
Mayday, Police call for backup, TV signal gets knocked off the air, you
won't have a clue why.

I have experimented with Easy Pal Digi SSTV and DRM it is neat but I can
rarely get the S/N high enough for a complete transfer. Text is more
reliable, but it is hard for me to put my faith in a signal that sounds
clean and strong to my ear but with no result. I could have passed several
photos on MMSSTV with half the S/N and knew well what they were. Sometimes
getting the information through is more important than waiting for
conditions to get better to get it perfect.

I don't mind being a network admin. but being a radio op isn't quite dead
yet.

picture breaks up and quits. At other times the same station will give a
solid 3 or 4 bars.This happens on all channels. Perhaps atmospheric
movement? Lots of dust here in the desert. Any other ideas?


Yes, ducting and "ghosting" of the signal(s) due to reflections, etc.--I
can see these as being a REAL problem. From your description(s), sounds
like "they" just took the exact-same
technology/encoding/decoding-schemes and implemented them onto broadcast

John Smith wrote:
Easy, with digital you are simply determining whether a signal is
present--or on (a binary one), on not--and off (a binary zero) ... an
analog signal contains much more data which can "screw up."

OTOH, when the digital signal is neither a one nor a zero,
or the CRC doesn't check, it fails completely while the
analog signal is slowly fading away.

During Hurricane Ike, all the digital signals here failed
while the analog signals were still (noisily) providing
useful information.

I hear digital voice used on HF amateur radio has the
same problem.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:

...
I hear digital voice used on HF amateur radio has the
same problem.

Amateur digital communications have one real and serious problem, they
have not adopted Ogg Vorbis as their standard digital
encryption/coding/decoding/error-checking "mode"--indeed, an actual
"superset" of Ogg Vorbis is needed for radio duplex communications ...
amateurs, in general, need be the "final designers"--that won't happen
until larger numbers are involved.

Ogg Vorbis is open source, free to use/implement in your own software,
it just doesn't get the blessing of the arrl and it can't be used as an
excuse to inflate prices ... :-(

Until that is established as a standard, Ogg Vorbis, (or, a "mode"
invented/designed/implemented with the same
redundancy/efficiency/fool-proof-ness), these problems will be of a
notable nature ... :-( How and when to request re-sending of error
packets, how many times these requests can be allowed, how long to hold
a packet in the buffers, how large of buffers to be used, size of the
packets allowed, etc., etc., etc will all need to be agreed upon in that
standard--so far NONE I HAVE SEEN ARE ADEQUATE--indeed, only one is on
the right track at all ... and, the standard can be designed to be
highly adaptable/upgradeable--with only firmware upgrades needed to
bring old hardware completely up-to-date (manufacturers will surely
attempt to get in control of this and be able to force the purchase of
new equip/planned-obsolescence by the denial of new "flash firmwares" or
designing new firmware upgrades in such a manner as make existing equip
unable to accept them, example, just make it too large for the present
memory(s) size(s) and disallow memory upgrades--you know, the "standard
stuff" already being done. grin)

While you and a buddy can use it between yourselves, or, you can attempt
to get your club interested ... it remains on the fringes ... I find
"digital hams" on the HF bands to be as rare as "chickens teeth", at
least ones working with decent digital transmission
software/algorithms/etc. ... :-(

There was a group of hams which broke away from all this are were going
to release open source code which would have to be accepted just because
of its' sheer efficiency and performance ... internal bickering and
outside pressures had/has brought its' progress to a crawl/halt at the
present time ... such "tinker-ings" gets the attention of high powers in
high places ... :-(

(or, is this all just my paranoia--I will allow you and the future to
decide ...) digital radio is coming ... it is just walking with a cane!
LOL

Regards,
JS