[MLStrand56]

Here's a really odd situation. Where I live ALL cable TV is NTSC (actually stolen sat. TV). All analog TV's scan for avail. cable ch. & assign them according to their cable frequency. BUT when HDTV's scan for avail. ch, ALL the avail. NTSC channels get assigned different Ch. numbers. Why would that be? It's the same cable frequency, same NTSC signal, so why a different CH. number?

With all the HDTV's avail. here (Philippines), you have to specify the geographic region that you want the TV to auto-program for. The Cable company says to use the USA region to program HDTV's. Using USA region gives a few good quality channels, but most are unwatchable. Using one of the other region settings always gives more good quality ch's, but on yet different channels. Each region setting seems to provide different good quality stations, & different assigned ch. for the same NTSC frequency.

With a NTSC TV, ALL stations are good quality (as good as NTSC can be). Is it possible that HDTV's have inferior NTSC tuners compared to the analog tuners in NTSC TV's?

Judging from all the bad looking NTSC signals on HDTV's, I won't buy ANY HDTV here.

Any Thoughts? Anybody?

MLStrand56

[coastie65]

Hi, I don't know because in most cases they are digital and should use the ATSC tuner that are pretty much standard on HDTVs today. Don't know about the P.I. though, but I would think that most satelitte programming is digital, meaning you would need an ATSC tuner ( that is why you need the box on older TV's as they have an NTSC tuner ). This is not to mention the fact that a lot of channels are scrambled as well and the box acts as a decscrambler ( decoder ).

[MLStrand56]

coastie65, on 21 January 2012 - 09:08 AM, said:

I would think that most satelitte programming is digital, meaning you would need an ATSC tuner ( that is why you need the box on older TV's as they have an NTSC tuner ). This is not to mention the fact that a lot of channels are scrambled as well and the box acts as a decscrambler ( decoder ).

I'm sure that all the Satellite downlinks are digital now. But the cable TV company only puts analog NTSC on the Cable service. There are Zero digital channels avail. on Cable. That's because very few (mostly foreigners) can afford to buy a HDTV. How's a filipino who makes the equalivent of $1.50/DAY, gonna afford a $5,000 HDTV?

Anyway I'm still trying to figure out Why a NTSC TV signal is on a particular TV CH, but assigned a different CH # on a HDTV?

Has anybody run into this in USA? OR maybe USA HDTV's don't even have a NTSC tuner?

Even if you happen to be rich enough to subscribe to Sat. TV, there are only a handful of HD signals avail. on Sat.

MLStrand56

[mjd420nova]

All of the signals coming off the satelite are digital. The box selects and decodes each chosen channel. The TV would be set to receive on only one channel and would decide if it's NTSC(analog) or HD(digital). The main channels are straight numbers and the digital ones would be a channel number with a DASH and its digital number. CH.#2 or #2-1. Broadcast signals are now all digital and require a converter for analog sets. HD sets can tune regular channels, both SD and HD. Analog displays are 640 by 480. The first level of HD is 720 by 568. Many sets can decode some control functions that are imbeded within the video frame and this can confuse some sets and render the picture unviewable. When the same signal passes through a different source, that content may be stripted away and yield a good picture. You have to choose the source for the best picture. Channel numbering can be confusing when signals are from private or NONBROADCAST sources. I have an HD set that can tune in a CH # 1. It contains a program guide that is surprisingly more accurate than some other sources available through satelite or cable. Ch.# 1 hasn't existed since the very beginning of the broadcast days.

[MLStrand56]

mjd420nova, on 21 January 2012 - 07:23 PM, said:

All of the signals coming off the satelite are digital. The box selects and decodes each chosen channel. The TV would be set to receive on only one channel and would decide if it's NTSC(analog) or HD(digital). The main channels are straight numbers and the digital ones would be a channel number with a DASH and its digital number. CH.#2 or #2-1. Broadcast signals are now all digital and require a converter for analog sets. HD sets can tune regular channels, both SD and HD. Analog displays are 640 by 480. The first level of HD is 720 by 568. Many sets can decode some control functions that are imbeded within the video frame and this can confuse some sets and render the picture unviewable. When the same signal passes through a different source, that content may be stripted away and yield a good picture. You have to choose the source for the best picture. Channel numbering can be confusing when signals are from private or NONBROADCAST sources. I have an HD set that can tune in a CH # 1. It contains a program guide that is surprisingly more accurate than some other sources available through satelite or cable. Ch.# 1 hasn't existed since the very beginning of the broadcast days.

Slight correction, Broadcast signals are now all digital in USA. Has the FCC mandated that All NTSC broadcasts be turned off? Last I knew (2007) broadcast stations had the option of broadcasting dual signals (on different carriers of course).

All Cable TV channels in my area are NTSC ONLY & there are NO digital broadcast TV signals. Maybe in Manila or Cebu, digital Ch's are avail on Cable. I don't live in either place, so I just don't know if digital cable signals are avail there. There is NO broadcast digital TV anywhere in Philippines.

So USA HDTV's are capable of receiving NTSC TV directly? But are NTSC ch's assigned the same Ch # on NTSC & HDTV's? Here NTSC signals are Always assigned different Ch. #'s on HDTV, than on NTSC TV's. Even though they are the exact same signal, they end up on different Ch. #'s.

I am fully aware how Sat. TV works. After retireing from the Air Force, I spent several years installing Dish Network Sat. TV receivers. I also worked as a commercial Satellite Earth Station Engineer which included NBC Sat. signals.

MLStrand56

This post has been edited by MLStrand56: 21 January 2012 - 10:20 PM

[waldojim]

You are thinking of over the air broadcast. SATELLITE is different. Sat systems use a combination of analog/digital for primary transmissions, and digital for ALL secondary transmissions. The very few analog systems in place are for very specific uses (for the most part). EG: Live news feeds. They still use analog most of the time because it is easier to maintain a usable signal in poor conditions. The secondary feeds are generally transmitted over VERY large, strong satellites capable of getting the digital signal through just about any cloud cover, or other adverse conditions. The digital feed also allows them to cram many, many more signals on a single transponder. This is how Dish can offer up 250 channels while watching a single bird. By doing this, they also delayed the inevitable replacement of the currently orbiting satellites.

SO, the end result here, is that while analog is still used in some cases for satellite feeds, it is extremely uncommon and not meant for viewing in either event.

[mjd420nova]

I see that not all users of analog microwave links for onsite news have no bought any new relay or video vans. They haven't been forced to abandon a workable system as yet because the normal 4 MHZ video link takes up a smaller percentage of bandwidth. Many out lying relays are still fed from analog links but have to be converted before retransmission on alloted broadcast frequencies. What the cable and satelite systems is their closely guarded secret. Encryption has come a long ways and hologram keycards make excellent security guards. Older systems are held to different shutdown dates based on how fast the conversion takes hold. Eventually. Many years ago the US Navy found PCM broadcasts were received over four times longer distances at lower frequencies than before. This was an eventual combination with fax and away it went. Next was 16 channels stacked on a single carrier and then carrier was removed (DSB double sideband). Had super range at even 8 MHZ, beyond 1,300 miles. Originally channel was too low in frequency that stations in different cities were bounced off the ionosphere(skip) and even over powering local stations a thousand miles away. It was quickly dumped. Then UHF came along. More channels, 14 to 83. Next the closed cicuit came about and cable service was a mere idea. Since cable service signals were never broadcast over the air, they took advantage of a gap in frequencies and assigned LETTER channel designators and a reqular TV could not tune to those channels. Again converters were needed to allow a normal set access to cable content without needing a set top box. Premium channels were offset some from normal in an effort to reach beyond a receivers tuning range. What they do now are trade secrets.

[MLStrand56]

Well, I finally found out why HDTV's in Philippines assign a different channel number, than NTSC TV's do. It's because ALL the HDTV's sold here are PAL not NTSC. That's about as smart as selling PAL TV's in USA.

MLStrand56

[waldojim]

MLStrand56, on 05 February 2012 - 03:24 PM, said:

Well, I finally found out why HDTV's in Philippines assign a different channel number, than NTSC TV's do. It's because ALL the HDTV's sold here are PAL not NTSC. That's about as smart as selling PAL TV's in USA.

MLStrand56

That is interesting. HD signals should not follow EITHER standard - hence the reason digital transmissions are called ATSC. Also, interesting note - most European equipment will work with any standard.