After the TV transmitters leave UHF & VHF...

[Wazzie]

I know the FCC is wanting TV to go digital to open up a bunch of space. But after Feb 19, will John Q Public be able to hear police & fire calls on their old TVs via rabbit ears? Or will everything be encoded? I've never really heard what the game plan is, after the switch.

Thanks-

Waz

 

[KR4BD]

My understanding is that this vacated spectrum will be digital with much trunking. So, your old TV won't hear anything but static and buzzing noises.

 

[dave73]

I just wonder about existing digital TV's with channels 52-69 on them. I don't know if the frequencies being reassigned will use slight different frequencies to keep the digital TV's from hearing anything.

 

[KE4KLS_Radio]

A digital TV signal would use a different codec (MPEG-4, for example) for receiving television signals compared to two-way communications. Because of this, it would be unlikely to receive two-way signals through a digital tv even though both utilize digital transmissions.

 

[stan]

So I assume that TV's channel 6 will no longer have audio at 87.7 FM?

 

[Bongwater]

My guess is the old transmitters will be sold to places like Africa and Southeast Asia, where the time for digital conversion will still be a long ways off......

 

[radioguybroadcasting]

Stan.... I don't think Channel 6's after the digital transition will have audio on 87.75

Bong.. you're right... these analog transmtiters that arent being used will be shipped off elsewhere.

 

[neo11]

Regarding Channel 6, an exception would be if it is a LPTV station. Such is the case in New York City, where a LPTV station on Channel 6 is operating as a radio station, Pulse 87. LPTV stations are not bound by the February 2009 analog shutdown, and while they will eventually have to go digital as well, I do not believe a specific cutoff date has been announced yet by the FCC. So in the short-term, at least, New Yorkers will still hear a "radio" station on 87.75 FM.

 

[LynnW]

My guess is the old transmitters will be sold to places like Africa and Southeast Asia, where the time for digital conversion will still be a long ways off......

Africa is all PAL or SECAM. Several countries, including Namibia, South Africa and Nigeria are already making the transition. I expect other are, too. I expect they will all use DVB-T.

The only countries in Asia using NTSC are Japan, South Korea, Taiwan, the Phillipines and Myanmar. Japan, South Korea and the Phillipines all in the midst of switching the digital the Phillipines being the last to shut of analog signals in 2015. I doubt it is legal to ship the transmitters to Myanmar.

So, all those old analog transmitters are headed for the recyclers.

 

[radioguybroadcasting]

My guess is the old transmitters will be sold to places like Africa and Southeast Asia, where the time for digital conversion will still be a long ways off......

Africa is all PAL or SECAM. Several countries, including Namibia, South Africa and Nigeria are already making the transition. I expect other are, too. I expect they will all use DVB-T.

The only countries in Asia using NTSC are Japan, South Korea, Taiwan, the Phillipines and Myanmar. Japan, South Korea and the Phillipines all in the midst of switching the digital the Phillipines being the last to shut of analog signals in 2015. I doubt it is legal to ship the transmitters to Myanmar.

So, all those old analog transmitters are headed for the recyclers.

Why would it be ill-legal to ship transmitters to Myanmar?

 

[Bongwater]

My guess is the old transmitters will be sold to places like Africa and Southeast Asia, where the time for digital conversion will still be a long ways off......

Africa is all PAL or SECAM. Several countries, including Namibia, South Africa and Nigeria are already making the transition. I expect other are, too. I expect they will all use DVB-T.

The only countries in Asia using NTSC are Japan, South Korea, Taiwan, the Phillipines and Myanmar. Japan, South Korea and the Phillipines all in the midst of switching the digital the Phillipines being the last to shut of analog signals in 2015. I doubt it is legal to ship the transmitters to Myanmar.

So, all those old analog transmitters are headed for the recyclers.

Why would it be ill-legal to ship transmitters to Myanmar?

Rogue nation status.

 

[willcail]

Woo Whoo Digital trunking!!!

Anyways ASTC video is MPEG-2 (or in plain speak standard def DVD video quality.) The biggest question is that if there is a demand for 87.7 to be grandfather in the FM Audio band? Most if not the majority of FM radios can tune into 87.7. Since the AM Band was expanded in 1993 from 1600KHZ to 1710KHZ will they do the same for 87.7? I'm guessing that there are groups out there want to set up a community/not for profit/public radio stations.

In Columbus the non com side of the FM radio band is quite full. 88.1 88.3 89.7 90.5 91.5 all occupied. In Westerville Ohio I can pick up 89.1FM. Right now there are two groups are fighting over 88.3. One is a Christian broadcast company want to use it as a repeater and another group want to do a full power Pacifica affiliate with a translator for Columbus.

There is WCRS LPFM witch is the current Pacifica affiliate.

 

[kenglish]

You guys just gave me an idea....
KSL-Radio does BYU local games, but, due to legal ("Bleep") issues, as well as the HD Radio encoding delay, the broadcast audio is about 14-15 seconds delayed. This annoys the crowd that wants to listen to OTA play-by-play.
The stadium is too big to do a Part-15 FM transmitter system, unless it was a very expensive one with distributed transmitters.

Maybe we should license a five or ten watt LPTV on TV channel 6 (inside the stadium), and just run an ID on the video, but with live, undelayed audio on 87.75.

 

[w9wi]

I know the FCC is wanting TV to go digital to open up a bunch of space. But after Feb 19, will John Q Public be able to hear police & fire calls on their old TVs via rabbit ears? Or will everything be encoded? I've never really heard what the game plan is, after the switch.

Only UHF frequencies are being removed from TV service. Four channels' worth of spectrum in what used to be the 60s is being reserved for public-safety communications.

I don't think the technical rules have been set yet. But I would be virtually certain that trunked technology will be used, and strongly suspect digital modulation will be used. Trunking would make monitoring on an old TV difficult, (because the frequencies will change often) and digital would make it impossible. (even on a digital TV, as the digital protocol will be different)

Actually, because of the way analog TVs work it's unlikely you'd hear police calls even if they were transmitted in standard analog. TVs use something called "intercarrier sound" which means the picture signal is used in the frequency conversion process for the sound. If there is no picture signal then the sound signal cannot be demodulated.

(in the few cases where someone has reported hearing a two-way call on a TV, it's almost certainly because another two-way call just happened to occur at the same time on a frequency 4.5MHz lower, simulating a picture signal.)

 

[TomT]

1. The more modern TV transmitters will/have been retuned to a lower channel & re-used for digital use. Example: One of the Chigaco commercial stations (channel 2, I do believe) bought the non-comm. Channel 11 site and transmitter and will move their digital signal to that facility. The non-comm went up into the UHF band. As long as the transmitter is fairly linear, it will pass the digital signal from a new digital exciter. The old analog exciter will be obsolete. Older transmitters will probably be sent south or parted-out.

2. Much of the new band will be used for some kind of trunked, digital communications, or various data signals. Nothing that the rather conventional FM audio portion of an analog TV set will be able to decode.

3. The TV audio/87.7 FM stations work because analog TV audio is an FM transmission mode, albeit with different pre-emphasis and narrower deviation (since deviation is essentially equivalent to modulation and to "loudness," that's why TV audio sounds so much lower on an FM radio). The audio signal(s) are embedded into the HDTV signal, so no audio can be heard on the lower part of a standard FM from an HD signal on channel 6.

 

[semoochie]

There's some discussion of 2012 as the cutoff date for translators, LPTVs and Class As.

 

[willcail]

Hmm the local LPTV stations in the Columbus Ohio would be pushed off the air permanently. With the exception of GTN TV23 witch is on the Insight Cable system, and the local Azteca America affiliate will survived. The other stations will disappear. Won't miss much one is a Daystar affiliate, one is a local Christan station that puts out a measly 80KW and a home shopping network affiliate with a creepy station ID.

 

[w9wi]

Hmm the local LPTV stations in the Columbus Ohio would be pushed off the air permanently. With the exception of GTN TV23 witch is on the Insight Cable system, and the local Azteca America affiliate will survived. The other stations will disappear. Won't miss much one is a Daystar affiliate, one is a local Christan station that puts out a measly 80KW and a home shopping network affiliate with a creepy station ID.

All of the LPTVs/Class A's in Columbus have permits to convert to digital except channel 48.

48 has two digital applications on file, one for a second-channel operation on 25 and the other to flash-cut to digital on 48. The FCC hasn't acted on either application yet.

No guarantee any of these will be built but the permits are in place.

I think you mean 80 watts (not 80KW) for channel 8 -- they have an application on file to increase to 3,000 watts (the maximum limit for LPTVs on VHF) and their digital conversion permit specifies the maximum limit for VHF LP digitals.

 

[boiseengineer]

There was a lot of excitement way back in 2001 when the FCC opened up channel 200 87.9. So far only a single 10-watt class D KSFH in Mtn View CA and a translator in Sun Valley NV seem to be licensed to 87.9.
Btw, the CDBS doesn't seem to understand Channel "200" and comes up with nothing. The raw database does show those 2 licensees.

 

[nd2023]

I know the FCC is wanting TV to go digital to open up a bunch of space. But after Feb 19, will John Q Public be able to hear police & fire calls on their old TVs via rabbit ears? Or will everything be encoded? I've never really heard what the game plan is, after the switch.

Only UHF frequencies are being removed from TV service. Four channels' worth of spectrum in what used to be the 60s is being reserved for public-safety communications.

I don't think the technical rules have been set yet. But I would be virtually certain that trunked technology will be used, and strongly suspect digital modulation will be used. Trunking would make monitoring on an old TV difficult, (because the frequencies will change often) and digital would make it impossible. (even on a digital TV, as the digital protocol will be different)

Actually, because of the way analog TVs work it's unlikely you'd hear police calls even if they were transmitted in standard analog. TVs use something called "intercarrier sound" which means the picture signal is used in the frequency conversion process for the sound. If there is no picture signal then the sound signal cannot be demodulated.

(in the few cases where someone has reported hearing a two-way call on a TV, it's almost certainly because another two-way call just happened to occur at the same time on a frequency 4.5MHz lower, simulating a picture signal.)

So if a picture signal is needed to demodulate audio, how come people in New York City can hear Pulse 87.7 on an FM radio?