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

JB wrote:
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.


Actually, NOT. Even the simple bars on a cell phone tell you if
communication is possible or not. The software running on an up-to-date
rig can describe the exact reason to you, if your rig interfaces to your
computer screen ... not to mention broadcast HDTV is in its' infancy,
taking its' first baby-steps ... even if you give the avg. American TV
viewer this information, do you think he would know what to do about it?
For "those dummies" you will pretty much have to have the software
handle the problems ... or make simple recommendations, perhaps "MOVE
THE ANTENNA DUMMY", or "RAISE THE ANTENNA DUMMY", or "BUY A DECENT
EXTERNAL ANTENNA DUMMY", or "POSSIBLE SIGNAL REFLECTIONS ARE OCCURING,
MOVE/REPOSITION THE ANTENNA DUMMY", etc. ROFLOL!

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.


If the binary signal just clears the noise floor, and not by much mind
you (I am hesitant to quote an exact figure here) a perfect signal is
quite possible ... that is simply the nature of digital.

I just don't know why anyone would claim that digital signals are not
MUCH superior to analog -- remember the old analog cell phones -- who
would ever wish to "go-back-there???" ... the only software I have used
with HF/VHF/UHF digital processing is open source ... I immediately made
modifications to the decoding/coding scheme (Ogg Vorbis), "packet hold
time" and size of the buffers and implemented my own CRC checking
(faster algorithm) ... however, others must get a copy of it from me and
we both share it or no communications are possible. I see amateur
software in the same light I see amateur antennas -- build your own or
have another amateur elmer/tutor/instruct/assist/share-with-you ... it
is just traditional and the true spirit of amateur radio ...

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


I actually worked at the college I attended in the 1990's when I
returned to go "full into computers" (my previous degree was as in
electronic engineering), and before I began an intern position in my
field of study. My last few months, before receiving my diploma, the
actually created a new position for me, "Student Programmer", I was
actually quite proud of it--even though the "big boys" seen it as a
joke! LOL Being both a programmer and a network admin. assistant made
the job seem like "money for nothing", what other sys admins seen as
major problems and were on the phone to Digital Equipment Corp. (DEC)
over, for the VAX, I usually had fixed by the time the techs got there
.... made me rather "hated", really ... however, most finally came around
and asked for the perl-scripts and C programs I used to automate every
task I could find! ... common computer users worshiped us ... "some of
us" let this go to their heads ...

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?


As I have said, I am anxious for it to be deployed in my area ... I am
already looking into "digital to analog conversion boxes" which I can
download the firmware from to "reverse engineer" and then flash open
source firmware into ... either by hook or by crook. grin

Only God can control atmospheric conditions (but then, there is HARRP
and other such projects which do SEEM to alter them), and who can stop
that neighbor from erecting that steel storage shed, building that
wrought iron fence, installing those bars on his windows, operating that
ham rig from his stealth antenna grin, etc? :-(

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


Regards,
JS

"John Smith" wrote in message
...
JB wrote:
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.


Actually, NOT. Even the simple bars on a cell phone tell you if
communication is possible or not.

That is all it can tell you.

The software running on an up-to-date
rig can describe the exact reason to you, if your rig interfaces to your
computer screen ...

Maybe you know of a secret diagnostic menu for my DTX9900?
If I remember correctly, all they know is RSSI and data errors. Please,
tell me if there are other indications that discern multipath, interference,
or any other reception problem without either sophisticated test equipment
or an analog indication - perhaps a color coded bar graph or channel
spectra that can react faster than the stream filling the buffer. I don't
know how ATSC handles error correction, but being a broadcast stream, I
would suppose only forward error correction is possible.

If the binary signal just clears the noise floor, and not by much mind
you (I am hesitant to quote an exact figure here) a perfect signal is
quite possible ... that is simply the nature of digital.

PACTOR yes, but I don't see that with DRM or ATSC at all. How is it that an
s9 signal isn't enough? I'm truly glad to have SSB so I can tell the other
station to resend the file again. The Universe isn't digital. Certainly
not radio. The signal, no matter what modulation scheme you use to improve
recovery of usable clipped and buffered data, is still in the realm of the
analog during transmission over the air. Ok, you might not understand that
if you are only the network guy and all your traffic worries start at the
protocol level as long as the Fiber box is energized.

don't know why anyone would claim that digital signals are not
MUCH superior to analog -- remember the old analog cell phones -- who
would ever wish to "go-back-there???"

Actually the best sounding mobile phone I ever had was my full-duplex 450
Motrac linked to a mountain top site with wide area direct dialing. No one
ever suspected I was mobile. But that was because my Analog link was better
than a voice grade phone line. Digital is great if you can find the
bandwidth, but great sacrifices and compromises have often been made in
audio quality for the sake of keeping the occupied bandwidth of the RF
channel within limits. What I am seeing on DTV, are stations that are doing
one 1080i or 720p stream on one RF channel with maybe 2 more streams of 480i
(often annoyingly compressed) OR up to 6 - 480i streams not so heavily
compressed. So I hate to disappoint you, that not all channels will be
better than analog until they find a way to do better than MPEG compression
and conversion from an NTSC source.

The move to digital cellular allowed channel re-use without having the
customer hear interference from co-channel sites so that many sites could be
used to communicate with many small handsets. Do you think that will be
much of an issue on Ham radio? Ham radio's greatest protection is in the
fact that it isn't supposed to compete with other services. No privacy is
needed or allowed either. If you copy the consumer model, you have no
amateur radio anymore. So I ask you sir, wouldn't you rather be using a
digital cell phone and leave the ham bands alone? Experimentation will
continue and things will be learned, people will contest and rag chew and
chase DX, but when ham radio for free is simple enough to compete with cell
phone services or a twisted pair, there will be a problem.

"John Smith" wrote in message
...
JB wrote:
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.


Actually, NOT. Even the simple bars on a cell phone tell you if
communication is possible or not. The software running on an up-to-date
rig can describe the exact reason to you, if your rig interfaces to your
computer screen ... not to mention broadcast HDTV is in its' infancy,
taking its' first baby-steps ... even if you give the avg. American TV
viewer this information, do you think he would know what to do about it?
For "those dummies" you will pretty much have to have the software handle
the problems ... or make simple recommendations, perhaps "MOVE THE ANTENNA
DUMMY", or "RAISE THE ANTENNA DUMMY", or "BUY A DECENT EXTERNAL ANTENNA
DUMMY", or "POSSIBLE SIGNAL REFLECTIONS ARE OCCURING, MOVE/REPOSITION THE
ANTENNA DUMMY", etc. ROFLOL!

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.


If the binary signal just clears the noise floor, and not by much mind you
(I am hesitant to quote an exact figure here) a perfect signal is quite
possible ... that is simply the nature of digital.

I just don't know why anyone would claim that digital signals are not MUCH
superior to analog -- remember the old analog cell phones -- who would
ever wish to "go-back-there???" ... the only software I have used with
HF/VHF/UHF digital processing is open source ... I immediately made
modifications to the decoding/coding scheme (Ogg Vorbis), "packet hold
time" and size of the buffers and implemented my own CRC checking (faster
algorithm) ... however, others must get a copy of it from me and we both
share it or no communications are possible. I see amateur software in the
same light I see amateur antennas -- build your own or have another
amateur elmer/tutor/instruct/assist/share-with-you ... it is just
traditional and the true spirit of amateur radio ...

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


I actually worked at the college I attended in the 1990's when I returned
to go "full into computers" (my previous degree was as in electronic
engineering), and before I began an intern position in my field of study.
My last few months, before receiving my diploma, the actually created a
new position for me, "Student Programmer", I was actually quite proud of
it--even though the "big boys" seen it as a joke! LOL Being both a
programmer and a network admin. assistant made the job seem like "money
for nothing", what other sys admins seen as major problems and were on the
phone to Digital Equipment Corp. (DEC) over, for the VAX, I usually had
fixed by the time the techs got there ... made me rather "hated", really
... however, most finally came around and asked for the perl-scripts and C
programs I used to automate every task I could find! ... common computer
users worshiped us ... "some of us" let this go to their heads ...

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?


As I have said, I am anxious for it to be deployed in my area ... I am
already looking into "digital to analog conversion boxes" which I can
download the firmware from to "reverse engineer" and then flash open
source firmware into ... either by hook or by crook. grin

Only God can control atmospheric conditions (but then, there is HARRP and
other such projects which do SEEM to alter them), and who can stop that
neighbor from erecting that steel storage shed, building that wrought iron
fence, installing those bars on his windows, operating that ham rig from
his stealth antenna grin, etc? :-(

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


Regards,
JS

------------

My following comments are totally off topic and are the mutterings of an old
curmudgeon. You have been warned.

What the hell happened to the word "saw"? I seen this, or I seen that.
Folks, that isn't correct. How can you get through four years of college
without using the "saw", except for when referring to a woodworking tool?

It is - "I saw that". Not, "I seen that". For crying out loud!!! G

Ed Cregger

On Tue, 16 Sep 2008 17:41:49 GMT, "JB" wrote:

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.

Unfortunately, you're correct. I have considerable experience dealing
with various path impairment issues using various wireless
technologies, especially Wi-Fi. User will complain that they loose
connectivity, drop connections, suffer from erratic performance, and
generally see performance well below what would normally be expected.
The sources are many and varied. They're also very difficult to
identify. Quite a bit can be deduced with simple diagnostics (i.e.
ping stability, MAC layer packet loss, retransmissions) and from
determining the pattern (does it always die during meal times), but in
general, it's way beyond the capabilities of Joe Sixpack. I expect
much of the same with digital TV.

However, I'm not worried much about the RF issues. It will either
work or the customer can get cable or satellite TV. What I'm worried
about are all the added cables and incompatible technologies found on
the back of the HDTV sets and boxes. Another tangle of wires to deal
with.

Anyway, radio is magic. Maybe I should get one of those Halloween
pointed sorcerers hats with the stars and crescents.
http://en.wikipedia.org/wiki/Image:MGM_sorcererhat.jpg

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com
# http://www.LearnByDestroying.com AE6KS