🚀 go-pugleaf

On Wed, 18 Jun 2008 10:09:59 -0500, "Ron T." <not@home> wrote:

>Being an inquiring mind that wants to know, I was in touch with some station 
>engineers about the digital wave coming, and the fact that their digital 
>signals were a fraction of their analogs.

suppposedly once the analogue signals are shut off, they are gonna
crank up the power on the digital ones.

"John Hines" <john@jhines.org> wrote in message 
news:rtji545a49152p741khacmo14v9s7uh9ja@4ax.com...
> On Wed, 18 Jun 2008 10:09:59 -0500, "Ron T." <not@home> wrote:
>
>>Being an inquiring mind that wants to know, I was in touch with some 
>>station
>>engineers about the digital wave coming, and the fact that their digital
>>signals were a fraction of their analogs.
>
> suppposedly once the analogue signals are shut off, they are gonna
> crank up the power on the digital ones.

I was wondering about this, but I'm not crazy about what I'm finding out.

Where I'm at, the digital side of the stations are from iffy to just not 
there.

When I check the database, I see stations running like 100kw ERP, and then 
the digital side goes from 18kw, 7kw, and 3.4kw.

The station engineer, stating that the digital signal could "theoretically" 
go farther, caught me off guard. If you have, say, a 180 mhz signal at 10kw, 
it doesn't matter if it's carrying an analog or digital content, it's going 
to be the same damn signal strength under whatever conditions at whatever 
distance.

The analog signal, however, will be usuable (though degraded) far beyond a 
digital signal which I believe drops usability somewhere around 25-30%. 

Ron T. wrote:
> The station engineer, stating that the digital signal could "theoretically" 
> go farther, caught me off guard. If you have, say, a 180 mhz signal at 10kw, 
> it doesn't matter if it's carrying an analog or digital content, it's going 
> to be the same damn signal strength under whatever conditions at whatever 
> distance.

What DOES matter, as you perceive, is the sensitivity of the encoding and
decoding process to noise. You can make out an analog signal that is FAR
lower in signal-to-noise ratio than is possible with a digital signal. So
if the signal is the same strength, but too far down in the noise floor to
detect, the analog signal gets viewed and the digital isn't there, for all
practical purposes.

-- 
                Britney Spears' Guide to Semiconductor Physics
                     <http://britneyspears.ac/lasers.htm>

Ron T. wrote:
> "John Hines" <john@jhines.org> wrote in message 
> news:rtji545a49152p741khacmo14v9s7uh9ja@4ax.com...
>> On Wed, 18 Jun 2008 10:09:59 -0500, "Ron T." <not@home> wrote:
>>
>>> Being an inquiring mind that wants to know, I was in touch with some 
>>> station
>>> engineers about the digital wave coming, and the fact that their digital
>>> signals were a fraction of their analogs.
>> suppposedly once the analogue signals are shut off, they are gonna
>> crank up the power on the digital ones.
> 
> I was wondering about this, but I'm not crazy about what I'm finding out.
> 
> Where I'm at, the digital side of the stations are from iffy to just not 
> there.
> 
> When I check the database, I see stations running like 100kw ERP, and then 
> the digital side goes from 18kw, 7kw, and 3.4kw.
> 
> The station engineer, stating that the digital signal could "theoretically" 
> go farther, caught me off guard. If you have, say, a 180 mhz signal at 10kw, 
> it doesn't matter if it's carrying an analog or digital content, it's going 
> to be the same damn signal strength under whatever conditions at whatever 
> distance.
> 
> The analog signal, however, will be usuable (though degraded) far beyond a 
> digital signal which I believe drops usability somewhere around 25-30%. 
> 
I'm just guessing, but you may be able to increase the distance of a 
usable digital signal by increasing the number of parity bits.  Then it 
becomes a matter of how big of a buffer the receiver has, and how much 
of a delay is acceptable.

Ian S. Salisbury wrote:
> Ron T. wrote:
>> "John Hines" <john@jhines.org> wrote in message 
>> news:rtji545a49152p741khacmo14v9s7uh9ja@4ax.com...
>>> On Wed, 18 Jun 2008 10:09:59 -0500, "Ron T." <not@home> wrote:
>>>
>>>> Being an inquiring mind that wants to know, I was in touch with some 
>>>> station
>>>> engineers about the digital wave coming, and the fact that their 
>>>> digital
>>>> signals were a fraction of their analogs.
>>> suppposedly once the analogue signals are shut off, they are gonna
>>> crank up the power on the digital ones.
>>
>> I was wondering about this, but I'm not crazy about what I'm finding out.
>>
>> Where I'm at, the digital side of the stations are from iffy to just 
>> not there.
>>
>> When I check the database, I see stations running like 100kw ERP, and 
>> then the digital side goes from 18kw, 7kw, and 3.4kw.
>>
>> The station engineer, stating that the digital signal could 
>> "theoretically" go farther, caught me off guard. If you have, say, a 
>> 180 mhz signal at 10kw, it doesn't matter if it's carrying an analog 
>> or digital content, it's going to be the same damn signal strength 
>> under whatever conditions at whatever distance.
>>
>> The analog signal, however, will be usuable (though degraded) far 
>> beyond a digital signal which I believe drops usability somewhere 
>> around 25-30%.
> I'm just guessing, but you may be able to increase the distance of a 
> usable digital signal by increasing the number of parity bits.  Then it 
> becomes a matter of how big of a buffer the receiver has, and how much 
> of a delay is acceptable.

Guess#2  DirecTV sends a digital signal over a pretty big distance, 
would an analog signal make it that far without scattering and bouncing 
and reflecting all over the place, even interfering with itself?

There's some ham operators in here, aren't there?

"Ian S. Salisbury" <isalisb@nospam.gmail.com> wrote in message 
news:g40gku$pn4$1@ftupet.ftupet.com...
>> I'm just guessing, but you may be able to increase the distance of a 
>> usable digital signal by increasing the number of parity bits.  Then it 
>> becomes a matter of how big of a buffer the receiver has, and how much of 
>> a delay is acceptable.
>
> Guess#2  DirecTV sends a digital signal over a pretty big distance, would 
> an analog signal make it that far without scattering and bouncing and 
> reflecting all over the place, even interfering with itself?
>

> There's some ham operators in here, aren't there?

Yes

The digital age has come around long after I got my license, and I've only 
tracked it a wee bit.

Hell, I didn't even do packet, and it's been around forever.

OK.....let me think......you have a signal that is, lets say 10 mv at your 
location.

Now, lets say that you have an antenna that is delivering that signal to the 
receiving equipment at -20 dbm.

Your receiver is sensitive enough to give you a snowy, but distinguishable 
video display at that strength.

Digital requires a stronger signal to read the bits, i don't think it's gonn 
make it.

The station engineer that stated, "theoretically a digital signal could go 
farther", also stated in a second e-mail that, "people who have a marginal 
analog signal now will probably not be able to get us after the switchover".

RF is RF....it's simply a medium to carry information. Its' going to act the 
same, after being affected by atmospheric conditions, sun spots, and 
physical obstacles no matter what info it's carrying.

So....no....no way do I see any upside for anyone in a less than pristine 
receiving position.

Apparently the FCC is mandating much lesser ERP's for digitals than analogs, 
and that's going to be the fly in the soup.

Of course, that pretty much just affects people like me, who are in a market 
where they have some locals that refuse to be carried on satellite, and can 
only be viewed OTA.

Any MIT'ers out there who want to comment or dispute, please keep it simple.

Between this and commenting on the Supreme's gun decision, I ahve used most 
of my thought process allocated for this month. 

Ian S. Salisbury <isalisb@nospam.gmail.com> wrote:
> Ron T. wrote:

>> The station engineer, stating that the digital signal could "theoretically" 
>> go farther, caught me off guard. If you have, say, a 180 mhz signal at 10kw, 
>> it doesn't matter if it's carrying an analog or digital content, it's going 
>> to be the same damn signal strength under whatever conditions at whatever 
>> distance.
>> 
>> The analog signal, however, will be usuable (though degraded) far beyond a 
>> digital signal which I believe drops usability somewhere around 25-30%. 
>> 
> I'm just guessing, but you may be able to increase the distance of a 
> usable digital signal by increasing the number of parity bits.  Then it 
> becomes a matter of how big of a buffer the receiver has, and how much 
> of a delay is acceptable.


I think the station engineer poorly worded his answer, 

"could theoretically go farther"

sort of depends which side of the fence you are standing on.

I think what he meant was, the signal is usable at a certain point where
before it wasn't. Keep in mind the old ntsc signal is a rather complex
combination of fm signals mixed together. The further you move away from the
transmitter, the weaker the signal gets. The picture starts getting snowy,
sound starts to hiss, the color may of pop in and out.

The digital channel is just carrying bits of data, no complex fm waveforms
to try to recover. If the tv/antenna is seeing the data stream, it more or
less "just works". 

With the ntsc/analog system, I beleive the minimum voltage you wanted down
from the antenna was 1000 microvolts on any channel. That figure was high
enough for any tv to pick up an acceptable and usable signal. The point to
make here is, if on any particular channel you were getting 1000uV or
10,000uV, there wasn't any difference in the picture/sound. As long as
1000uV was available, you got a good picture and clear sound.

I think with the digital broadcasting you just need to slide that scale down
to like 100uV and 1000uV. I'm not saying that is correct and it's really 10x
better or more sensitive, but because it's only data bits to deal with, you
just don't need the same level of power to make it work.

Looking at it from the transmitter side, if a station was permitted to cover
a radius of 50 miles, with analog they probably need 10 million watts to get
the 1000uV out at the 50 mile point. With a digital only signal to get 100uV
(again guessing on that), you simply won't need the same amount of power.

The plain english explanation is simply compare it to the old analog cell
phones and current digital ones. The analogs were much bigger, batteries
didn't last as long because they were basically a analog radio transmitter
and receiver. The current digital ones don't broadcast a fm signal to get
picked up, it's a spray of bits on a given frequency at flea power compared
to the old analog ones. The batteries can last for days.

Again, all this is a WAG but seems to fit the reason why the digital
transmitters are at a much lower power output than the analog counterparts
but still cover the same range in reality. They simply don't need to
broadcast at those higher levels.

-bruce
bje@ripco.com

Ron T. wrote:
> "Ian S. Salisbury" <isalisb@nospam.gmail.com> wrote in message 
> news:g40gku$pn4$1@ftupet.ftupet.com...
>>> I'm just guessing, but you may be able to increase the distance of a 
>>> usable digital signal by increasing the number of parity bits.  Then it 
>>> becomes a matter of how big of a buffer the receiver has, and how much of 
>>> a delay is acceptable.
>> Guess#2  DirecTV sends a digital signal over a pretty big distance, would 
>> an analog signal make it that far without scattering and bouncing and 
>> reflecting all over the place, even interfering with itself?
>>
> 
>> There's some ham operators in here, aren't there?
> 
> Yes
> 
> The digital age has come around long after I got my license, and I've only 
> tracked it a wee bit.
> 
> Hell, I didn't even do packet, and it's been around forever.
> 
> OK.....let me think......you have a signal that is, lets say 10 mv at your 
> location.
> 
> Now, lets say that you have an antenna that is delivering that signal to the 
> receiving equipment at -20 dbm.
> 
> Your receiver is sensitive enough to give you a snowy, but distinguishable 
> video display at that strength.
> 
> Digital requires a stronger signal to read the bits, i don't think it's gonn 
> make it.
> 
> The station engineer that stated, "theoretically a digital signal could go 
> farther", also stated in a second e-mail that, "people who have a marginal 
> analog signal now will probably not be able to get us after the switchover".
> 
> RF is RF....it's simply a medium to carry information. Its' going to act the 
> same, after being affected by atmospheric conditions, sun spots, and 
> physical obstacles no matter what info it's carrying.
> 
Except that digital signals are designed knowing that some of the data 
is going to be lost.  They use parity checking and buffers at the 
receiving end to make the best attempt at putting the whole signal 
together.

I was responding to the theoretical aspect of it, not the real world.

If you lived at the very outskirts of the signal and you recorded an 
hour worth of data, the parity bits would tell you which packets are 
bad.  If they sent the same data stream again, and you had enough 
buffers to replace the bad packets, you would have as good of a 
recording as someone next door to the transmitter.

It's the same reason you can scratch the hell out of a CD and it will 
still play. (until you scratch out too much parity info)

But in the real world, they only send a little redundant data and the 
buffers in the receivers are only big enough to handle a few seconds of 
it, if that.

And my question from guess #2, is really; could you actually broadcast 
an analog TV signal from NY to LA with enough juice?  We know that audio 
can in the AM band, but what about Video in the UHF?

Ian S. Salisbury <isalisb@nospam.gmail.com> wrote:

> And my question from guess #2, is really; could you actually broadcast 
> an analog TV signal from NY to LA with enough juice?  We know that audio 
> can in the AM band, but what about Video in the UHF?


If the earth was flat, no problem.

Being it's not, the only way to get from NY to LA would be if the
atmospheric conditions were right and it bounced up and down to get there.

There are actually a few "world records" for long distance tv veiwing, I'm
probably mistaken but top honors I beleive was some guy in New Zealand
picked up some kind of watchable signal from Michigan. Or maybe it was
Michigan from Chile. I don't run across those much anymore, probably due to
cable and people not "spinning the dial" anymore.

But the point is, that was all due to weather conditions.

If the curvature of the earth wasn't involved, enough power could get a
signal from anywhere to anywhere.

-bruce
bje@ripco.com

Bruce Esquibel wrote:
> Ian S. Salisbury <isalisb@nospam.gmail.com> wrote:
> 
>> And my question from guess #2, is really; could you actually broadcast 
>> an analog TV signal from NY to LA with enough juice?  We know that audio 
>> can in the AM band, but what about Video in the UHF?
> 
> 
> If the earth was flat, no problem.
> 
> Being it's not, the only way to get from NY to LA would be if the
> atmospheric conditions were right and it bounced up and down to get there.
> 
> There are actually a few "world records" for long distance tv veiwing, I'm
> probably mistaken but top honors I beleive was some guy in New Zealand
> picked up some kind of watchable signal from Michigan. Or maybe it was
> Michigan from Chile. I don't run across those much anymore, probably due to
> cable and people not "spinning the dial" anymore.
> 
> But the point is, that was all due to weather conditions.
> 
> If the curvature of the earth wasn't involved, enough power could get a
> signal from anywhere to anywhere.
> 
Cool.

"Bruce Esquibel" <bje@e4500.ripco.com> wrote in message 
news:g412c3$hcq$1@e250.ripco.com...
> Ian S. Salisbury <isalisb@nospam.gmail.com> wrote:
>
>> And my question from guess #2, is really; could you actually broadcast
>> an analog TV signal from NY to LA with enough juice?  We know that audio
>> can in the AM band, but what about Video in the UHF?
>
>
> If the earth was flat, no problem.
>
> Being it's not, the only way to get from NY to LA would be if the
> atmospheric conditions were right and it bounced up and down to get there.
>
> There are actually a few "world records" for long distance tv veiwing, I'm
> probably mistaken but top honors I beleive was some guy in New Zealand
> picked up some kind of watchable signal from Michigan. Or maybe it was
> Michigan from Chile. I don't run across those much anymore, probably due 
> to
> cable and people not "spinning the dial" anymore.
>
> But the point is, that was all due to weather conditions.
>
> If the curvature of the earth wasn't involved, enough power could get a
> signal from anywhere to anywhere.
>
> -bruce
> bje@ripco.com

Good reply, Bruce.

When I was up north, there were frequent ducts to Ohio and Southern Indiana. 
I could often watch TV out of those areas.

I think that *theoretically*, one could  broadcast from New York to 
California.

If you knew (1) How microvolts you needed at a given spot in California at 
the elevation that you want to recieve (2) How many db of loss you're going 
to encounter at the particular frequency and (3) Height of your transmitting 
antenna, you can figure out how much power you'll need to get a usable 
signal there.

Take into account that @ 150 mhz, RF horizon is 4/3 of actual horizon.

Actual horizon at sea, IIRC, is 14 miles.

At marine freq's, 162 mhz, ships have no problem communicating simplex much 
farther than actual horizon.

That's why we can hear low power airplane transmissions from a *long* way 
away.

Problem being, we'd have this *huge* directional antenna on top of the 
Empire State Building, pumping 2 1/2 million kw into it with enough ERP 
emitted to fry New York, and insure that there wouldn't be another baby made 
until you get on the west end of Oklahoma.

I'm not doing anything this weekend, Bruce, shall we try it?

We'll build a yagi out of 12" reinforced pipe, piggyback some miltary grade 
linear amps, and set off every burglar alarm, garage door opener, and fry 
every pacemaker through central U.S. and southern Canada.

In reality, I welcome the switch from Never The Same Color to Always The 
Same Color, but it is giving me some fits out here in Green Acres.

Ever tune the old analog cell phones on that tubed 19" in the garage?

"Bruce Esquibel" <bje@e4500.ripco.com> wrote in message 
news:g412c3$hcq$1@e250.ripco.com...
> Ian S. Salisbury <isalisb@nospam.gmail.com> wrote:
>
>> And my question from guess #2, is really; could you actually broadcast
>> an analog TV signal from NY to LA with enough juice?  We know that audio
>> can in the AM band, but what about Video in the UHF?
>
>
> If the earth was flat, no problem.
>
> Being it's not, the only way to get from NY to LA would be if the
> atmospheric conditions were right and it bounced up and down to get there.
>
> There are actually a few "world records" for long distance tv veiwing, I'm
> probably mistaken but top honors I beleive was some guy in New Zealand
> picked up some kind of watchable signal from Michigan. Or maybe it was
> Michigan from Chile. I don't run across those much anymore, probably due 
> to
> cable and people not "spinning the dial" anymore.
>
> But the point is, that was all due to weather conditions.
>
> If the curvature of the earth wasn't involved, enough power could get a
> signal from anywhere to anywhere.
>
> -bruce
> bje@ripco.com

I had a reply typed up to this and then hit the wrong button.

Good reply, Bruce. 

"Ron T." <not@home> wrote in message 
news:T6OdnR9Y_o3vifnVRVn_vwA@giganews.com...
>
> I had a reply typed up to this and then hit the wrong button.
>
> Good reply, Bruce.
>

 Guess it made it anyway.

I let the root-doctor lady down the road use my computer.

I think she blew some goofy-dust on it. 

Ian S. Salisbury <isalisb@nospam.gmail.com> wrote:

> Cool.

I guess my google finger was broken before...

"TV DX hit a world record in 1957. One particular signal was picked up more
than 10,000 miles from its initial broadcast point. England's BBC was picked
up in southern Australia."

Seems to be agreed upon as the holding worlds record.

Really thought Michigan was involved in there somewhere.

-bruce
bje@ripco.com

On Jun 18, 1:11 pm, John Hines <j...@jhines.org> wrote:
> On Wed, 18 Jun 2008 10:09:59 -0500, "Ron T." <not@home> wrote:
> >Being an inquiring mind that wants to know, I was in touch with some station
> >engineers about the digital wave coming, and the fact that their digital
> >signals were a fraction of their analogs.
>
> suppposedly once the analogue signals are shut off, they are gonna
> crank up the power on the digital ones.

I suspect that CBS-2 has turned down the analog power a bit. The last
2 thunderstorms caused my VCR tuner to "lose" portions of letterman
and the sunday morning show...Diane Bums strikes again ?? JG

Ron T. wrote:
> Problem being, we'd have this *huge* directional antenna on top of the 
> Empire State Building, pumping 2 1/2 million kw into it with enough ERP 
> emitted to fry New York, and insure that there wouldn't be another baby made 
> until you get on the west end of Oklahoma.

In today's world I'm not sure that would be a problem for anyone or anything
but world communism.

-- 
                Britney Spears' Guide to Semiconductor Physics
                     <http://britneyspears.ac/lasers.htm>

Bruce Esquibel wrote:
> With the ntsc/analog system, I beleive the minimum voltage you wanted down
> from the antenna was 1000 microvolts on any channel. That figure was high
> enough for any tv to pick up an acceptable and usable signal. The point to
> make here is, if on any particular channel you were getting 1000uV or
> 10,000uV, there wasn't any difference in the picture/sound. As long as
> 1000uV was available, you got a good picture and clear sound.

We used to go for 3000 mV, to have enough to overcome ghosting from downlead
pickup / mismatch / etc. 1000 *good* mV gave a good picture, as you say.

-- 
                Britney Spears' Guide to Semiconductor Physics
                     <http://britneyspears.ac/lasers.htm>

"clifto" <clifto@gmail.com> wrote in message 
news:to16j5-bv5.ln1@remote.clifto.com...
> Ron T. wrote:
>> The station engineer, stating that the digital signal could 
>> "theoretically"
>> go farther, caught me off guard. If you have, say, a 180 mhz signal at 
>> 10kw,
>> it doesn't matter if it's carrying an analog or digital content, it's 
>> going
>> to be the same damn signal strength under whatever conditions at whatever
>> distance.
>

> What DOES matter, as you perceive, is the sensitivity of the encoding and
> decoding process to noise. You can make out an analog signal that is FAR
> lower in signal-to-noise ratio than is possible with a digital signal. So
> if the signal is the same strength, but too far down in the noise floor to
> detect, the analog signal gets viewed and the digital isn't there, for all
> practical purposes.
>

Zactly, clifto.

Not much info out there, and what is being provided can be misleading.

I'm still seeing commercials that are stating, "If you watch TV with an 
outside antenna, you're not going to get anything after Feb 2009".

What bullshit. That's gotta have more than a few old ladies running out to 
buy a damned digital set to keep watching their soaps.

I need a TV built like my Miltronix-rebuilt R390a.

Bud, pull the antenna, crank it up, and there just *ain't* no noise.

Put two blow torches local, 10 khz apart, and you won't even know the other 
one's there, and I can still hear a mic cracked in the Gulf of Mexico on a 
piece of wire stuck in the high impedance antenna input.

Yes.....I need a TV built like that.