Channel Separation Rules for Digital TV

[KyDXIn]

"UHF channels went up to 83 until 1983, then the channels 70-83 were used for cellular phones."

And there was some pretty fun monitoring to be had on those channels for quite a few years.......

Please tell us more!

 

[Markxxx]

Do TV stations really care that much about OTA anymore?

 

[KeithE4]

"UHF channels went up to 83 until 1983, then the channels 70-83 were used for cellular phones."

And there was some pretty fun monitoring to be had on those channels for quite a few years.......

Not legally, but... ;D

 

[w9wi]

Do TV stations really care that much about OTA anymore?

Depends on the station, but probably more than you think. One local station just bought a new transmitter & antenna & the labor to install it just to improve their OTA signal. They were already hitting both satellite services just fine, and feed cable by fiber -- so this was entirely for OTA viewers.

We're seeing evidence of increasing use of OTA.

 

[landtuna]

"UHF channels went up to 83 until 1983, then the channels 70-83 were used for cellular phones."

And there was some pretty fun monitoring to be had on those channels for quite a few years.......

Please tell us more!

Originally those frequencies were used by analog cell phones and it was possible to intercept their signals and listen in although this was technically illegal. UHF radios manufactured after a certain date (which escapes me at the moment) were locked out of these frequencies. It was all made redundant when cell traffic became digital and thus, not interceptable.

 

[rgseark2009]

Thankfully KOAM Pittsburg KS which also uses RF13 post-transition is too close to the NW AR transmitter for AETN for KAFT to reuse their old analog channel, 13, for DTV (KAFT uses RF 9 instead).

KOAM went back to DT-7 after the transition. Its half-sister station, KFJX, uses DT-13, though, as it wasn't given a transitional channel because it was licensed after the deadline for transitional channels had passed.

Now that I remember.....but KFJX is a "sister" station of sorts for KOAM. Still too many ch 13's in and around Arkansas, regardless of callisign.

 

[rgseark2009]

Another problem comes from the stations themselves. During the DTV transition many stations on VHF opted for a huge power increase while keeping their antenna polarization either horizontal or vertical. Tests show that DTV VHF works best with a circular polarization pattern. In fact, a station stands a better chance being received indoors with less power and a CP pattern than more power and either a H or V pattern.

Vertical (only) polarization was not allowed for analog TV, and unless something happened I didn't run into, it's not permitted for digital either.

But your point is valid. Circular polarization made a BIG difference in analog and it would do the same in digital if more stations used it...

I was thinking of elliptical polarization which uses a combination of H and V. Some stations had adopted that method to improve reception.

That is what KATV Little Rock did with their current antenna. Mostly H polarization with some V tossed in. The only negative is that some electrical interference is manifest during nearby thunderstorms (not as severe as a high-VHF).

 

[kenglish]

Part of the problem with DTV on VHF stems from the way homes are constructed. Homes made of metal, stucco or concrete (with metal screen inside) or using foil backed insulation in the exterior walls can act as a Faraday cage making reception of VHF with indoor antennas very difficult. Then we have the antennas themselves which can introduce a 10 to 20 db loss on the VHF band.......

Plus, you have the problem with the junk INSIDE the homes...Big screen TV's "self-jam" themselves with their digital noise and the switched-mode power supplies, computers generate noise (plus the power supplies), routers and other parts of home networking stuff makes interference, and the Broadband-over-Power-Line ("Home Plug", etc) stuff destroys whatever is left.

Also, like you said, UHF "HDTV" antennas, used on VHF channels, are "no antenna at all".

 

[Carmine5]

Do TV stations really care that much about OTA anymore?

Absolutely. Recent stats from the NAB show that FOTA TV is growing. In addition to the "cord nevers" who are OTA only, many homes have secondary TVs that use an antenna. Notice these comments from the NAB to the FCC:

"Free over-the-air broadcast television is now the primary video programming delivery method for 17.8 percent of U.S. television households [This is up from 15% last year], representing 20.7 million households (or 53.8 million consumers)....There are approximately 41.2 million sets in over-the-air television households. An additional 32.5 million television sets in 17.7 million MVPD households remain unconnected to the MVPD service. Thus, a total of approximately 73.7 million television sets currently are not connected to any MVPD service and receive all broadcast signals over-the-air."

http://www.nab.org/documents/newsRoom/pdfs/091012_Video_Competition_Comments.pdf

Also, broadcasters firmly believe that their future lies in Mobile DTV. This, of course, takes spectrum which is why all of the full powers and the majority of Class As have stated that they will not participate in the VIA (despite Genachowski's pathetic pleadings).

 

[landtuna]

Also, broadcasters firmly believe that their future lies in Mobile DTV.

REALLY? As a long-time OTA viewer I am amazed that anyone, given an alternative, would prefer to watch any TV programming (much less sports or movies) on a 4-square inch screen with tinny ear buds or tinnier cell phone speakers. And watching on a tablet or netbook is not much better.

Just last night I was encouraging my 20-something son to watch a movie called "On Any Sunday". He dialed it up on his Droid and showed the opening to me. The picture was clear but very small and the sound was only a small spectrum of the real soundtrack. I didn't say a word when he folded up his phone and said he would watch it on his "big screen". Same reaction I would have had.

Perhaps for breaking news or the background noise of Youtube or TMZ mobile devices might be appropriate. For true television not a chance. And with the rapidly diminishing content value even those might not be enough to attract more than a few.

 

[Carmine5]

Also, broadcasters firmly believe that their future lies in Mobile DTV.

REALLY? As a long-time OTA viewer I am amazed that anyone, given an alternative, would prefer to watch any TV programming (much less sports or movies) on a 4-square inch screen with tinny ear buds or tinnier cell phone speakers. And watching on a tablet or netbook is not much better.

Just last night I was encouraging my 20-something son to watch a movie called "On Any Sunday". He dialed it up on his Droid and showed the opening to me. The picture was clear but very small and the sound was only a small spectrum of the real soundtrack. I didn't say a word when he folded up his phone and said he would watch it on his "big screen". Same reaction I would have had.

Perhaps for breaking news or the background noise of Youtube or TMZ mobile devices might be appropriate. For true television not a chance. And with the rapidly diminishing content value even those might not be enough to attract more than a few.

A survey conducted by Research Now showed that 68% of respondents (ages 18-54) were interested in watching live mobile TV with 61% saying that they would watch live TV on a smartphone. No doubt as customer data usage exceeds the data caps wireless companies have imposed, those numbers will go up. The goal is TV everywhere. The downside of Mobile DTV, at least for now, is the need for a telescoping antenna on the handset or tablet.

But I wouldn't say "not a chance" to anything related to DTV. The industry is already moving past current digital standards and traditional uses of broadcast television and adopting new ones. The potential is exciting and viewers will reap the benefits. Now if only the government will get the #&%! out of the way and let us innovate and stop providing free "deep massages" to the phone companies at our expense. The only thing they want to do is eliminate a competitor while keeping their customers chained to expensive data plans.

http://sucherman.com/2012/07/survey-mobile-dtv-could-change-tv-viewing-habits/

 

[landtuna]

Survey's are one thing. Actual usage is another. I'll stay tuned but I won't put a dollar on any investment that pushes for mobile TV when there are alternatives available.

 

[Darth_vader]

"Not legally, but..."

...everybody who was anybody did it anyways. The thing about these so-called "laws" is they are more-or-less unenforceable. A law can prevent people from selling and manufacturing sets designed to receive certain communications, yes. Unless there's a pig stationed at each and every radio-equipped house in Amerika (good luck with that) there's really nothing physically stopping from individuals from modifying their own receivers or listening to such signals on their own free will.

Of course, like landtuna said, this is pretty much irrelevant (not "reduntant") since everything on the cellular bands consists of data these days (just wideband "static" and buzzing noise on an analogue rig.)

"UHF radios manufactured after a certain date (which escapes me at the moment) were locked out of these frequencies."

1987. It was a condition of the passage of the so-called "Electronic Communication Privacy Act" (public law #99-508). The crop of police scanners that were coming out in the early 99-508 era were simply previous designs modified to exclude the cellular bands by having some components added to them; consequently they tended to be ridiculously easy to "fix" by removing these components. (In one familiar instance this consists of merely cutting the leads of a single diode on the tuner circuit to regain full 800 MHz coverage!)

All in all, it was really just an incredibly stupid legislative move all around.* They could have actually tried to secure their networks, which would have been the more responsible move to make, but merely leaving everything in the clear and still open to interception, whilst merely "criminalising" it, cost far less for the phone companies to implement in the long run. That, and implementing security (read: audio scrambling) would have required them to hire engineering staff with prescience, intelligence and initiative; unfortunately, as with most hierarchical structures, such positions are typically awarded on the bases of trust and obedience.

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*The exception being that it's possible to get hold of police scanners in which one doesn't have to repeatedly thumb past channel after channel after channel of hash noise when running in blind-scan mode! So it actually does have some benefit, albeit a minor (and originally unintended) one. Whoda' thought?