The Last Day of Analogue TV

[w9wi]

1. I've noticed that with mapping, the digital channels show the stations' traditional channels. I'm wondering if a UHF station that is also known by it's cable channel number, can remap to show itself as a VHF (ex., many of the CW and MYTV stations). For example, could WDJT in Milwaukee, which is ch. 58 on UHF (moving to 46 via DT) and ch. 5 most local cable outlets, rebrand itself as "CBS 5" and digitally map to there, or something like that? Or could ch. 44 in San Francisco just remap to ch. 12 DTV, as they're on 12 on area cable? This could be an interesting development, as tiny UHFs at the upper end of the dial could 'move down' to where the big boys feed.

It's my understanding that stations must remap to their current analog channel (even after transition), unless they don't have an analog channel in which case they must remap to their DTV channel. So WDJT must remap to 58.

2. As I understand, DTV won't need to crank out as much power, as they don't have the ghosting and static issues that analog has. Does this mean that signals for DTV stations won't be as powerful? I do notice that the DTV channels are closer together, and duplicate shorter distances away.

Comparing DTV and analog powers is somewhat like comparing apples and oranges.

Analog TV signals have predictable recurring power peaks, at the tip of each synchronizing pulse 15,750 (+/-) times a second. Analog power is measured at these peaks; a "5,000,000-watt" UHF station radiates 5 million watts only during the sync pulses. Their power averaged over a few seconds of time is considerably lower. (very roughly 2 million watts - it varies wildly with program material)

Digital signals also have power peaks, but you can't predict when they're going to happen. So DTV power instead is averaged across a brief period of time. The quoted power is average but the peak power is somewhat greater.

 

[arnoldevns]

It's my understanding that stations must remap to their current analog channel (even after transition), unless they don't have an analog channel in which case they must remap to their DTV channel. So WDJT must remap to 58.

That's kind of the point I was making about the oddity of the DFW market with KXTX and KLDT. (KXTX is analog 39 / digital 40 and KLDT is now digital only on channel 54 - it was analog channel 55)

For example: right now if I tune to channel 35 it puts me on 4.1. If I tune to channel 4 it also puts me on 4.1. So if I tune to 39 after this switch, where will it take me? To 54.1 or 39.1? In theory this shouldn't be a problem, but in reality I think it's going to create some tuning problems.

 

[dhett]

I don't have DTV yet, so I'm not 100% on this, but it's my understanding that tuning to the analog channel will get you the digital channel and tuning to the actual digital channel still gets you the digital channel, and will continue to do so until the old analog channel is filled. So if, after the transition, when KXTX is on D40 and KLDT is on D39, you would tune to ch. 39 to get KXTX. You might also get KXTX by tuning to ch. 40, but you will certainly not get KLDT on ch. 39. What I'm not certain of is how KLDT will work - will you tune to ch. 55, ch. 54, or ch. 40? I'm guessing either 55 or 54, or both, depending on how you get it now.

What I do know is that once the transition is over, if a new station starts up on an old analog channel, you will tune to the old analog station's actual digital station number to get the new station. Confusing? Here's an example: in Phoenix, KUTP is on channel N45, but has elected to stay on D26 post-transition. You will tune to ch. 45 to get KUTP, as before. However, if a new station starts up on D45 in Phoenix, you will tune to ch. 26 to receive it, not ch. 45, as ch. 45 will still map to KUTP.

Assuming the FCC hasn't changed their minds, there's another exception to the map-to-analog-channel rule that will come into play when LPTV channels go digital: for translator stations, you will now tune to the primary station's channel number. For example, Globe AZ will have the following lineup of translator stations:
16 - KFPH N13 Flagstaff (TFU) (actually broadcasting on D32)
22 - KSAZ N10 Phoenix (FOX)
27 - KPHO N5 Phoenix (CBS) (D17)
41 - KPAZ N21 Phoenix (TBN) (D20)
43 - KAET N8 Phoenix (PBS)
48 - KPNX N12 Phoenix (NBC)
50 - KTVW N33 Phoenix (UNI)
57 - KTVK N3 Phoenix (IND) (D24)
You will tune to chs. 13, 10, 5, 21, 8, 12, 33 and 3, respectively, to receive those channels.

 

[arnoldevns]

Assuming the FCC hasn't changed their minds, there's another exception to the map-to-analog-channel rule that will come into play when LPTV channels go digital: for translator stations, you will now tune to the primary station's channel number. For example, Globe AZ will have the following lineup of translator stations:
16 - KFPH N13 Flagstaff (TFU) (actually broadcasting on D32)
22 - KSAZ N10 Phoenix (FOX)
27 - KPHO N5 Phoenix (CBS) (D17)
41 - KPAZ N21 Phoenix (TBN) (D20)
43 - KAET N8 Phoenix (PBS)
48 - KPNX N12 Phoenix (NBC)
50 - KTVW N33 Phoenix (UNI)
57 - KTVK N3 Phoenix (IND) (D24)
You will tune to chs. 13, 10, 5, 21, 8, 12, 33 and 3, respectively, to receive those channels.

That's going to be an interesting mess in some places. It used to be that folks in Brownwood, Texas had translators for both WFAA Channel 8 in Dallas and KLST Channel 8 in San Angelo. I could be wrong, but I think they still do.

 

[Markxxx]

A station can map to whatever channel it wants. WCIU used to map to channel 1, till the FCC said "Cut that out."



There was talk of the WB wanting all it's affiliates to map to channel 75, in addition to their old analogue channel. That way anyone in any city could turn to Channel 75 and there would be the WB affiliate. (I think it was 75 maybe it was 74 but it was some number in the 70s.) Of course the WB is no more so I don't know if that idea will ever come about

 

[KML0224]

The low band VHF still has a few TV stations using it for their digital channels. Also remember the PSIP (used for virtual channel mapping among other things) varies from tuner to tuner.

I know of a guy in NE Maryland and one of this digital TVs will map BOTH channel 2 from New York City and Channel 2 from Baltimore. In other words when he scans channels it'll give him TWO channel 2s.

His other older set will not give him ANY channel 2s because the mapping on that tuner (a different one) doesn't know what to do, so after he scans the set for stations he has to manually enter the ACTUAL channel WCBS New York City and WMAR Baltimore are broadcasting on.

How is WCBS-DT showing up for him in Maryland?

 

[arnoldevns]

I know of a guy in NE Maryland and one of this digital TVs will map BOTH channel 2 from New York City and Channel 2 from Baltimore. In other words when he scans channels it'll give him TWO channel 2s.

His other older set will not give him ANY channel 2s because the mapping on that tuner (a different one) doesn't know what to do, so after he scans the set for stations he has to manually enter the ACTUAL channel WCBS New York City and WMAR Baltimore are broadcasting on.

So I assume as technology gets better this will be less of an issue.

This pretty much answers my question. On newer sets it all maps out the right way, but on older sets you might have a hard time getting the signal of either station.

 

[anotherguyTN]

So are there plans to allow new digital stations to come on at the old analog locations on a wide scale? I know that there are plans for a new station on channel 10 in Memphis once WKNO moves to its digital channel permanently. I would think though that in a case where a station has its digital channel right next to its analog channel that may not happen.

 

[dhett]

There was talk of the WB wanting all it's affiliates to map to channel 75, in addition to their old analogue channel. That way anyone in any city could turn to Channel 75 and there would be the WB affiliate. (I think it was 75 maybe it was 74 but it was some number in the 70s.) Of course the WB is no more so I don't know if that idea will ever come about

Correct. Tribune Broadcasting had reserved channel 75 in several cities. (See reserved list.) It was mistakenly thought that Trinity Broadcasting had reserved the channel. Also, USDTV had reserved channel 99 for their service using unused spectrum from existing channels in a market. They've since gone out of business. I think mapping to channels 70-99 was another exception, but one which, so far, has not come to fruition.

So are there plans to allow new digital stations to come on at the old analog locations on a wide scale? I know that there are plans for a new station on channel 10 in Memphis once WKNO moves to its digital channel permanently. I would think though that in a case where a station has its digital channel right next to its analog channel that may not happen.

Eventually, the abandoned frequencies will be available for assignment for secondary services like LPTV, just like any other frequency in the TV spectrum, as long as they do not interfere with primary services (full-power TV) and agree to accept any interference from primary services. In the DTV world, stations on adjacent channels will be common, as long as their transmitters are co-located, as they are not supposed to have the interference problems that you get with analog. See Buffalo, NY in the DTV Table of Allocations (large PDF file). That said, in the real world, there can be issues between full-power and low-power stations, requiring low-power stations to boost their signal strength to mitigate interference from a much more powerful adjacent station. See KAZT-CA's application for STA (large PDF file).

Reserved ATSC virtual channels: http://www.atsc.org/standards/virtual_channels.html
DTV Table of Allocations: http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-07-138A2.pdf
KAZT-CA application for STA: http://svartifoss2.fcc.gov/prod/cdbs/forms/prod/getattachment_exh.cgi?exhibit_id=517198

 

[CW]

Overall there are 517 stations whose permanent DTV assignment is the same as their current analog assignment.

If you mean only among low-band VHF stations, there are 24 such assignments. In four of these cases, the stations are relatively new and didn't receive a second interim channel for DTV.

[/quote]

Yep, I should have clarified that....I knew there were SOME Lowband DTVs after the sunset date..but would have thought the ones already on VHF Hi or UHF would have stayed there....and 4 going NEW to lowband?? ANy bets on how long they will stay there????

 

[w9wi]

Yep, I should have clarified that....I knew there were SOME Lowband DTVs after the sunset date..but would have thought the ones already on VHF Hi or UHF would have stayed there....

In five cases, the station didn't have the option of remaining on its interim UHF DTV channel; that channel is above 51 & will be deleted on transition. One would think they could have negotiated to obtain someone else's abandoned UHF channel though. With the possible exception of WPVI in Philadelphia - congestion in that area is such that I would not be surprised if no alternative channel was available.

Only two stations with a VHF-Hi interim DTV assignment are returning to their VHF-Lo analog channel. (WBKP-5 at the tip of Michigan's Upper Peninsula & KYUS in the nation's smallest market, Miles City, Montana) Why I have no idea. Quite possibly they expect nobody outside the station's (geographically tiny) city of license to actually watch the OTA signal, in which case the low-band channel may be quite adequate & will cost less to run.

and 4 going NEW to lowband?? ANy bets on how long they will stay there????

In three cases here there was no choice in the other direction - the station's old analog channel is outside core.

 

[Markxxx]

You can sometimes get NYC in Maryland. I lived there and had no trouble, during the summer getting Channel 12 from Richmond and Channel 17 from Philadelphia.

This poster was in NE Maryland, so it's possible with a high antenna to pick up NYC's channel 2. It's not a regular thing but it's do-able.

I know WWME-CA Channel 23 has applied to get a digital channel on Channel 39 in Chicago, so it seems as if the low power TV stations are going digital too. The bad thing is once the low power digital TV is up and running WCIU says it will stop carrying channel 23's programing on their subchannel. Which may make it hard for people who can get digital WCIU but will be too far to receive the low power TV WWME when it moves to Channel 39.