ATSC frequencies

[mattopia]

Hi all,

Question on ATSC frequencies used for OTA digital broadcasts. It was my understanding that all digital OTA is UHF, so that the VHF spectrum used for channels 2-13 can be cleared up after the digital cutover.

However, I'm now seeing indications that anything on ATSC channels 2-13 are really using the same 2-13 frequencies used by NTSC/analog?

Can anyone shed some light?

I ask because I"m using a DB2 in my attic for local OTA, and channel 3 (which is on ATSC frequency 2) will drop out ever so briefly from time to time. I always assumed it's because the antenna is in my attic, but it could be because it's VHF and the DB2 is UHF only.

 

[VinceT3]

the spectrum being sold is somewhere in the middle of 2-69 if I remember correctly..

Ultra high frequency - Wikipedia, the free encyclopedia

698–806 MHz: TV channels 52–69 (to be auctioned for other uses once conversion to digital TV has been accomplished)

 

[Peter Parker]

After the cutover there will be full power channels from Ch 7 and up and some LPTV all the way down to Ch. 2. The UHF frequenciwes above I believe 51 will be auctioned off.

 

[mdonnelly]

Hi all,

Question on ATSC frequencies used for OTA digital broadcasts. It was my understanding that all digital OTA is UHF, so that the VHF spectrum used for channels 2-13 can be cleared up after the digital cutover.

However, I'm now seeing indications that anything on ATSC channels 2-13 are really using the same 2-13 frequencies used by NTSC/analog?

Can anyone shed some light?

I ask because I"m using a DB2 in my attic for local OTA, and channel 3 (which is on ATSC frequency 2) will drop out ever so briefly from time to time. I always assumed it's because the antenna is in my attic, but it could be because it's VHF and the DB2 is UHF only.

All digital is NOT UHF. A substantial number of stations will either continue to use channel numbers in the 2-13 range as they do now (KOCO-DT uses 7 in OKC), or will revert to their analog channel number at the cutover so they can use the higher powered VHF transmitter for the digital signal.

See here.

 

[GeorgeLV]

After the cutover there will be full power channels from Ch 7 and up and some LPTV all the way down to Ch. 2. The UHF frequenciwes above I believe 51 will be auctioned off.

Your information is incorrect.

Licensed full-power stations can be anywhere from 2-51 post transition.

 

[MW390]

Hi all,

Question on ATSC frequencies used for OTA digital broadcasts. It was my understanding that all digital OTA is UHF, so that the VHF spectrum used for channels 2-13 can be cleared up after the digital cutover.

However, I'm now seeing indications that anything on ATSC channels 2-13 are really using the same 2-13 frequencies used by NTSC/analog?

Can anyone shed some light?

I ask because I"m using a DB2 in my attic for local OTA, and channel 3 (which is on ATSC frequency 2) will drop out ever so briefly from time to time. I always assumed it's because the antenna is in my attic, but it could be because it's VHF and the DB2 is UHF only.

I was told by a knowledgable person that UHF channels 62-69 were being freed up. These frequencies supposedly will be used for emergency personnel nationwide (such as NYPD and NYFD) to communicate with each other.

 

[twaller]

Your information is incorrect.

Licensed full-power stations can be anywhere from 2-51 post transition.

While this statement is true, it has been proven that channels 2-6 are not well suited for ATSC transmission as they are too prone to interference. There are some that suggest that post-transition we could be dealing with a spectrum of 7-51.

 

[mattopia]

While this statement is true, it has been proven that channels 2-6 are not well suited for ATSC transmission as they are too prone to interference. There are some that suggest that post-transition we could be dealing with a spectrum of 7-51.

So I guess a lot of wait and see. I know that we have a local station on channel 2 and it seems to be very problematic to receive, even with the transmitter being about 2 miles away. The rest of the stations (all ch10 and up on their ATSC transmissions) come in nearly perfect with a paper clip stuck in the OTA input.

 

[VinceT3]

I don't think there are any digital stations in my area that are in the 2-6 range (2, 4, 5, & 6 are all analog currently)

 

[Jim5506]

I counted 31 low vhf full power stations in the FCC list after 2009.

 

[Tower Guy]

While this statement is true, it has been proven that channels 2-6 are not well suited for ATSC transmission as they are too prone to interference. There are some that suggest that post-transition we could be dealing with a spectrum of 7-51.

The situation on low band VHF is not as clear as you might think. Yes, there is a huge problem in Michigan and Illinois because WWMT and WBBM interfere with each other. They are close spaced. Channel 2 is both WWMT-DT and WBBM analog. WBBM-DT and WWMT analog are both on channel 3.

The lowest low band channels also suffer from reception problems when using receive antennas that are close to the ground. The ground effect significantly tilts up the beam. The noise problem on low band VHF drops about 1 db per channel as you go from channel 2 up to channel 6. The combination of ground effect and noise make channels 4-6 far better than 2 or 3. The low band issues can be completely resolved if the FCC were to allow low band DTV stations to increase power after the analog stations are turned off.

 

[rad]

WBBM-DT is fixing their problem by moving to channel 11 after analog shutdown IIRC.

 

[Peter Parker]

While this statement is true, it has been proven that channels 2-6 are not well suited for ATSC transmission as they are too prone to interference. There are some that suggest that post-transition we could be dealing with a spectrum of 7-51.

As I mentioned many of the stations that will still broadcast on the lower frequencies ar LPTV---and they can continue to broadcast in analog. So while some suggest that 2-6 will go away there are stations interested in using these frequencies.

 

[Jim5506]

Final FCC channel listing shows 31 FULL POWER channel 2-6 stations after 2009. They are here to stay.

 

[navychop]

But the analog LPTV stations will have a sunset date set.

 

[Peter Parker]

Really. good catch Navychop any dea when? I understand that someone asked for Ch 2 in DC>

 

[navychop]

Hmmm. Channel 2? That's new to me. Double ungood. Might be a small religious station?

The third round election did not affect northern VA. No channel 2 designations.

The second round moved WNVC (NTSC channel 56) from 57 to 24 for digital. This had to be, since channels 52 an up will soon be auctioned off for other purposes. Also, WPXW (NTSC channel 66) moves from 43 to 34. I would assume it's an interference issue. These folks multicast 6 programs. No channel 2 designations.

No one in round one selected channel 2.

Per this, in mid 2006 they stopped accepting analog LPTV applications and started the move toward digital. But as of that time, no specific date had been set for mandatory conversion. I'm sure if the LPTV NTSC station caused interference with an ATSC station, they'd be shut down pronto. But given the conditions under which LPTV stations exist, it is doubtful that there would be any interference. I haven't heard of any movement since then to define a cutoff date. If they're hoping the point will be moot due to voluntary action, I think they're mistaken.

However, this doesn't look promising for converting to digital. I guess the money came out on the side of letting them stay analog for a while longer. But those analog TVs will slowly go away, and they're just putting off the expense. I'm not sure that it'll be any cheaper in the future- we're not talking consumer electronics here.

 

[GeorgeLV]

While this statement is true, it has been proven that channels 2-6 are not well suited for ATSC transmission as they are too prone to interference. There are some that suggest that post-transition we could be dealing with a spectrum of 7-51.

I don't necessarily disagree. But the fact remains is that as of today many full-power stations have elected to remain on low-vhf assignments post transition, including my local NBC station in Las Vegas, KVBC-DT on channel 2.

 

[Peter Parker]

Hmmm. Channel 2? That's new to me. Double ungood. Might be a small religious station?

The third round election did not affect northern VA. No channel 2 designations.

The second round moved WNVC (NTSC channel 56) from 57 to 24 for digital. This had to be, since channels 52 an up will soon be auctioned off for other purposes. Also, WPXW (NTSC channel 66) moves from 43 to 34. I would assume it's an interference issue. These folks multicast 6 programs. No channel 2 designations.

No one in round one selected channel 2.

Per this, in mid 2006 they stopped accepting analog LPTV applications and started the move toward digital. But as of that time, no specific date had been set for mandatory conversion. I'm sure if the LPTV NTSC station caused interference with an ATSC station, they'd be shut down pronto. But given the conditions under which LPTV stations exist, it is doubtful that there would be any interference. I haven't heard of any movement since then to define a cutoff date. If they're hoping the point will be moot due to voluntary action, I think they're mistaken.

However, this doesn't look promising for converting to digital. I guess the money came out on the side of letting them stay analog for a while longer. But those analog TVs will slowly go away, and they're just putting off the expense. I'm not sure that it'll be any cheaper in the future- we're not talking consumer electronics here.

I had read that Ch 49 intends to move to Channel 2 and I believe that there ere threads about it at the time. But since I cannot find a reference or that earlier thread I will retract my statement due to lack of proof. I must be wrong.

 

[navychop]

Hardly. They can apply for a frequency change anytime they want. I doubt that it would be a priority, given all the other moves. Maybe there's a blackout period until after the conversion.

But I've never heard of a channel 49 near northern VA. Low power?

Anyone asking for channel 2 should be denied, unless there are no other slots available. I suspect over the years the channel 2s and 3s (actual frequency assignments) will ask to be reallocated. But it's just one more nail in the coffin that is OTA broadcasting.