Looking at post-February 2009, some of my stations are moving their frequencies:

WPMT 43 is going to 47.
WBFF 45 is going to 46 (possible adjacent interference?)
WGCB 49 is going to 30.

Why? Why not just keep the same channel? Keep 43 on 43, 45 on 45, and 49 on 49. ----- It seems that, from an FCC bookkeeping perspective, it would be a lot easier to just assign DTV channels identical to the old ATV designations. "Randomly" moving channels without reason seems a great way for the FCC to make a mistake (in my humble opinion).

For example:

WBAL 11 and WBRE 28 were assigned by the FCC to the exact same digital frequency: 11. Ooops. Since they are 100 miles distant perhaps it won't matter, but why take the risk of same-channel interference? [Like I said, it seems easier for the FCC to just leave post-2009 channels in the same spot where they've always been.]

If you would post the call-signs of the stations, we could tell more about their particular situation. You keep posting channel #s, but that does not tell us very much. We can look up WMAR 2 or WBFF 45. The short answer to your question is that a majority of full power stations will stay on their current digital channel rather than spend $ to switch to their analog channel next year. But some 648 stations will be moving their assigned interim digital channel next year because they are moving to their analog channel, their digital channel is out of core at UHF 52 to 69 and they have to move, or they want to move to what they see as a better (or lower cost) channel for their location.

Read the upcoming final DTV table discussion thread at http://www.avsforum.com/avs-vb/showthread.php?t=823166 if you want some insight to this.

Looking at post-February 2009, some of my stations are moving their frequencies:

43 is going to 47.
45 is going to 46 (possible adjacent interference?)
49 is going to 30.

Why? Why not just keep the same channel? Keep 43 on 43, 45 on 45, and 49 on 49. -----
Adding to my answer, if 43 is WPMT Fox 43 in York, PA, the station is not "going" to UHF 47, it is currently digitally broadcasting on UHF 47 because 43 is occupied by the analog signal. WBFF-DT Fox 45 in Baltimore is digitally broadcasting on UHF 46 because 45 is occupied by the analog broadcast. They are are not "going to", they are on those channels. The PSIP header takes care of the channel mapping.

Both of these stations have selected to stay on UHF 47 and UHF 46 after February 17, 2009. But WGAL-DT NBC 8 in Lancaster, currently on UHF 58 which will be taken away from TV broadcasting next February, will move their digital broadcast to it's VHF 8 analog antenna.

Around here, the stations that are moving their digital signals to a different channel mostly fall into two categories: (a) they want to use the VHF channels that they're currently using for analog, mainly because VHF requires less power than UHF; (b) they must move because their current digital channels are above channel 51 and therefore must be vacated so the Feds can auction them off.

As far as I know, only one station is moving its digital signal from one UHF channel to another one without (apparently) being forced to do so: WGGS in Greenville SC, which currently has analog 16 and digital 35, and is going to move its digital signal to 16. IIRC they might even shut down their analog service early in order to do so.

Some stations will go back to their NTSC slots, others will stay where they are. It depends on a lot of factors. Low VHF for instance is not a desired location due to electrical noise. High VHF is a very desirable slot due to simpler transmitters and much lower power requirements. Also high UHF is not as easy to receive as a lower UHF spot.

As has already been mentioned there's lots of reasons.

For instance there's lots of broadcasters who are temporarily leasing spots on towers for their current digital broadcasts. So they'll be going back to their old tower location and old antenna and old Tx (and thus old channel assignment) after the shutdown.

And going back to their old antenna and Tx should give them the best chance of having the same coverage as the old analog station so that's a factor as well.

Here in Phoenix the only broadcasters that are NOT going back to their old channels are the two stations that are currently in the low vhf band. They're keeping their new UHF assignment.

This topic has been recently discussed.

1. Broadcasters were LOANED a 2nd channel to broadcast their digital signal simultaneously with their analog signal. When analog is turned off, one channel must be given back.

2. Current OTA TV in the USA is on channels 2-69. After 2/17/2009 only channels 2-51 will be used. The spectrum which currently makes up channels 52-69 is being "given" back to the government and will create the new 700 MHz band.

3. Most viewers will never see a virtual channel change. If a station was analog channel 3, it is labeled "3.1", etc on its digital channel. If/when the physical digital channel is changed, the station will still be called "3.1", etc.

4. Most stations do not want to broadcast digitally in channels 2-6. So those who can are moving to a higher channel.

5. Tower and antenna design of television broadcasters is highly complex (expensive & dangerous). There are logisitical reasons why stations may move their digital signal back to their analog channel or leave it at its current digital channel.

Also, you mentioned co-channel interference. Notice that cable companies ignored this issue and use every channel. The problem is mitigated with digital broadcasting, and any co-channel interference will be acceptable to new receivers.

Also, you mentioned co-channel interference. Notice that cable companies ignored this issue and use every channel. The problem is mitigated with digital broadcasting, and any co-channel interference will be acceptable to new receivers.
No, you can get adjacent channel interference with ATSC if one station is much stronger than the other. I'm sure someone here can quote the specs on this in terms of dB. The common setup with adjacent digital channels in the same market is to have the broadcast antennas at the same location (or on a nearby tower) so they have the same or close to the same coverage area. But if you are close to one DT station on UHF 46 (call it WBFF-DT) and are trying to pick up at distant DT 47 station (say WPMT-DT), you may have a problem locking onto DT 47. There is someone in Baltimore who has run into this trying to get WPMT-DT OTA so he can get the Eagles games, IIRC.

You will also see interference estimates for the primary and adjacent channels addressed in numerous recent filings with the FCC as the stations argue for increased power, or ask to use their current analog antenna so they don't have to buy an expensive new directional antenna, or for decreased power to meet the FCC maximum interference requirements. As an example, here is a engineering attachment from CBS for WJZ-DT CBS 13 in Baltimore which has asked to go to 28.8 kW on VHF 13 next year with a new directional antenna to maintain coverage of their market: http://fjallfoss.fcc.gov/prod/cdbs/forms/prod/getattachment_exh.cgi?exhibit_id=624669. Note the % interference issues with VHF 12 stations, especially WWPX-DT Ion 60 on VHF 12 to the west. I've have been keeping track of the stations in the Washington & Baltimore markets.

Cable transmission is a very different situation so there is not a adjacent channel concern there. For starters, each channel in theory should have close to the same signal strength at the tuner.

Some stations are making their permanent digital home on their current analog channels because they don't want the insanity of permanently mapping to a virtual channel that is different than their physical channel!

How can stations be allowed to keep virtual channels when that channel will soon be someone else's real channel?

Some stations are making their permanent digital home on their current analog channels because they don't want the insanity of permanently mapping to a virtual channel that is different than their physical channel!

That has nothing to do with it.

How can stations be allowed to keep virtual channels when that channel will soon be someone else's real channel?

Because the FCC has required it. If a post transition station begins broadcasting on a former analog channel and that channel number is in use in that market, the new station most pick an unused channel number and report it to the FCC. That is the law.

If you would post the call-signs of the stations, we could tell more about their particular situation. Fixed Post #1. I'm not sure why the call letters are relevant to my question? But I went ahead and added them anyway. The short answer to your question is that a majority of full power stations will stay on their current digital channel rather than spend $ to switch to their analog channel next year. Sounds like a mess for the FCC's bookkeeping to have all these stations moving-around (and error-prone). 5. Tower and antenna design of television broadcasters is highly complex (expensive & dangerous). There are logisitical reasons... Makes sense. Also, you mentioned co-channel interference. Notice that cable companies ignored this issue and use every channel. That's not co-channel interference. That's adjacent channel interference.

Co-channel interference is the case with WBAL 11 and WBRE 28, both broadcasting on digital channel 11, even though they are only ~100 miles apart. Like I said in post 1, it looks like that is a major error that the FCC made, and they would have been better off leaving WBRE on its previous 28 designation.

Not too bright IMHO.

if you are close to one DT station on UHF 46 (call it WBFF-DT) and are trying to pick up at distant DT 47 station (say WPMT-DT), you may have a problem locking onto DT 47. There is someone in Baltimore who has run into this trying to get WPMT-DT OTA so he can get the Eagles games, IIRC. That's my exact problem, but in the opposite direction (trying to watch Baltimore games but being over-powered by WPMT in Lancaster-York PA).

If these two stations had kept their old channels (45 and 43), then there'd be no problem with adjacent channel interference. That's been my whole "argument" behind creating this post. I could probably watch both! (And ditto your friend in Baltimore.) But with their new assignments, that's difficult to do. WJZ-DT CBS 13 in Baltimore which has asked to go to 28.8 kW on VHF 13 next year with a new directional antenna to maintain coverage of their market: http://fjallfoss.fcc.gov/prod/cdbs/forms/prod/getattachment_exh.cgi?exhibit_id=624669. Note the % interference issues with VHF 12 stations, especially WWPX-DT Ion 60 on VHF 12 to the west. I've have been keeping track of the stations in the Washington & Baltimore markets. Fascinating. WWPX-DT12 is ~55 miles away. You'd think that would be far enough not to cause issues with DT13, but apparently not! (Over 7,000 people will lose Martinsburg 12 due to increased power coming from Baltimore 13.)

And I see the Baltimore 13 overlaps with Scranton's 13. Another 7000 people will lose Scranton 13 due to the increased power at the Baltimore station.

Hmmm. What have you heard about WBRE-DT11 in Scranton interfering with WBAL-DT11 in Baltimore?

I think if you go back and check ALL the stations in your area for their Post D-Day plans (via their filed 387's) - you'll find that quite a bit of co- and adjacent channel interfernce will be going away, because most of the analog will be going away. I'd check in the last 5-10 pages of this thread http://www.avsforum.com/avs-vb/showthread.php?t=823166 for links to a more consolidated view of the entire post transition environment.

Post transition, some stations in my area are moving to hi-VHF, which requires less power to cover the same broadcast area. I'm not sure if that's their official reason for moving, but it's a practical one.

Most stations built full power digital transmitter facilities on their loaned frequencies. Unless there is a compelling reason for them to switch back to their analog frequency assignment, it would be needlessly expesive for them to do so. As mentioned earlier, those reasons would be - long term savings of using a more efficient VHF channel or the loss of an out of core (above ch. 51) digital channel.

Some analog transmitters already in use can be adjusted to work for digital transmission. This is going to be the case for two stations in my immediate area, and one station off into the market just west of me. In particular I'm talking about WCTI, WFXI and WTVD. These stations will go back to their analog VHF HI position. WCTI will give it's current digital frequency of 48 to WRAL which is on 53(analog 5). WTVD is on 52, so they have to find another spot and the obvious choice for them was their analog spot(11), since above 51 will not be used (as stated above). WFXI went with going back to their spot on 8 due to lower operating costs, and they will move their digital transmitter to the satellite WYDO's site which is operating digital on 21 but will go back to 14. (No idea why they chose to do that) Frequency 21 & 24 will vanish around here. WITN also in this market has a VHF on 7 that they were denied using due to interference with WFXI, (they will remain on UHF 32) so some have speculated that the Wilmington NC market may jump on this opening for it's weak signal WECT 44 which has lost more coverage with digital than any other station around. They broadcast analog on channel 6. WNCT in the market already was given channel 10 for digital originally, (they broadcast analog on 9) so they will not be doing anything.

As you can see there is a LOT of reasons why things happen the way they do and are going to happen.

While I think many or most stations who elected to stay on their current digital channel allocation post transistion did so because of the info Spwace posted ...

But Also, I suspect some number of stations may have returned to their analog assignment but the FCC's channel election rules were such that if they had they would have had to reduce coverage area(or negotiate NCE's with the involved station(s_)) to protect other stations service areas, stations which elected to stay on their current digital channel assignment.

In fact, several stations in my area originally elected in first round of channel election procedure to move to their analog channel assignment, but received interference conflict notices from FCC and then changed their election to their current digital channel assignment.

Basically, It was because, for the Channel election rules, The service areas for stations staying on their current digital channel allocations were protected on a "primary" basis, but with some "exceptions" for stations with out-of-core digital+analog channel assignments(and for those having only lo-VHF in-core assignment(s)), stations wanting to move their digital station to their analog channel had to protect nearby stations(who are staying where they are currently with digital) coverage areas.

While one might think that would not be a problem since the analog stations are already transmitting there, the interference protection criteria for DTV to DTV interference is a little different, and the interference protection critieria FCC used for channel election was especially "rigid", so to speak. That was probably a good thing, but I believe stations had originally been told they would have an equal choice between whether to use their current analog or digital channel assignment post transistion --- Which didn't turn out to be the case in some or many circumstances.

Those interested can find a more detailed and accurate explanation of all of this in the portion of FCC's 2nd DTV review Report and order which details the rules/procedures for Channel election, the entire text of 2nd DTV review R&O is currently availabe here (PDF format) :

http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-04-192A1.pdf

I have 4 stations currently broadcasting analog in hi-VHF. All of them are moving back next February. It should improve reception around the hills. I will have one adjacent channel, but in opposite directions.

If you want to see too close for comfort on channel 10's, take a look at this! WNCT DT kills WAVY's analog signal, and even cable companies couldn't fight the interference so I read a while back...

WAVY:
http://www.fcc.gov/ftp/Bureaus/MB/Databases/fm_tv_service_areas/maps/TV231273.gif

WNCT: (notice the overlap)
http://www.fcc.gov/ftp/Bureaus/MB/Databases/fm_tv_service_areas/maps/DT1005845.gif

Some analog transmitters already in use can be adjusted to work for digital transmission.

It's a lot more complicated than that. The exciter/modulator at the input to the transmitter and the filters on the output must be replaced. The exciter is an expensive but easy change out but the output filters are a different story. They are expensive and very large. If the station intends to keep it's analog signal up till the deadline the logistics become complex.

Some antennas used for analog are not suitable for digital and must be replaced, as well.

The price tag for all of this will be hundreds of thousands of dollars. So, you can see why a station would not want to through out a perfectly good digital transmission system.

Co-channel interference is the case with WBAL 11 and WBRE 28, both broadcasting on digital channel 11, even though they are only ~100 miles apart. Like I said in post 1, it looks like that is a major error that the FCC made, and they would have been better off leaving WBRE on its previous 28 designation.
WBAL-DT NBC 11 is currently broadcasting on UHF 59 at 513 kW, not on VHF 11. WBAL-DT will flash cut to VHF 11 next February 17. You need to look at the current digital channel, antena power and HAAT of the station in accessing why you are not getting it.

WBAL-DT 11 has applied for and been granted to broadcast at only 5 kW on VHF 11 next year - compared to the full monty of 316 kW for their current analog VHF 11 broadcast. WBRE-DT NBC 28 is at 30 kW on VHF 11 and will stay there, so WBRE-DT is putting out a fairly powerful signal for upper VHF. The WBAL-DT engineering attachment to their recent 301 application shows them to more concerned about interference with WVPT-DT PBS 51 in Staunton, VA also on VHF 11 to the SW. See http://fjallfoss.fcc.gov/prod/cdbs/forms/prod/getattachment_exh.cgi?exhibit_id=624629. They claim 0% expected interference with WBRE-DT. But there is no question that they are packing in the VHF 11 stations in the mid-Atlantic area.

Ah for the good old days of "bulletproof" tuners with real coils and slugs!

The newest generation two-chip/3 wire ATSC wonder-tuners have great "back-end" specs for decoding DTV, cancelling multipath, etc., but IMO they stink at "front end" specs. Let's face it, folks, even though the new modulation scheme is digital, RF is RF and the same kind of robust RF design as needed for NTSC would still be a big help. A nearby +50dBm ATSC signal will probably wipe out weaker DTV for several adjacent channels due to limited dynamic range and possibly overload/imtermodulation products.

On the other hand, ATSC has some built-in resistance to co-channel interference, somewhat like "capture effect" in FM demodulation, so closer spacing than present NTSC co-channels may work out just fine.

I think if you go back and check ALL the stations in your area for their Post D-Day plans (via their filed 387's) - you'll find that quite a bit of co- and adjacent channel interfernce will be going away. Can you do me a favor? Read post 1 again. Please note that channels 43 (DT47) and 45 (DT46) are adjacent and interfere. Please note that channels 11 (DT11) and 28 (DT11) in Baltimore/Scranton willb be cochannels post-2/2009, and they interfere.

The problem is NOT going away on February 18. That's not some magical fairy tale date where a witch will wave her wand & make everything perfect. The problems (for me at least) will still exist. WBAL-DT NBC 11 is currently broadcasting on UHF 59 at 513 kW, not on VHF 11. We're discussing the post February 2009 world, not the present conditions.

I reviewed your link. If I'm interpreting it correctly, channel 28 (DT11) in Scranton will lose 18,000 viewers due to interference from Baltimore. Staunton Virginia will only lose 1500. The impact to Scranton (and people living between these two stations) is greater.

The price tag for all of this will be hundreds of thousands of dollars. So, you can see why a station would not want to through out a perfectly good digital transmission system.

Ah, but some of us are.

Can you do me a favor? Read post 1 again. Please note that channels 43 (DT47) and 45 (DT46) are adjacent and interfere. Please note that channels 11 (DT11) and 28 (DT11) in Baltimore/Scranton willb be cochannels post-2/2009, and they interfere.

The problem is NOT going away on February 18. That's not some magical fairy tale date where a witch will wave her wand & make everything perfect. The problems (for me at least) will still exist. We're discussing the post February 2009 world, not the present conditions.

I reviewed your link. If I'm interpreting it correctly, channel 28 (DT11) in Scranton will lose 18,000 viewers due to interference from Baltimore. Staunton Virginia will only lose 1500. The impact to Scranton (and people living between these two stations) is greater.

I'll take this up later (re: your post transition situation).

Newbies...... they know it all.;)

Newbies...... they know it all.;)

I was tempted to say that early on.

Most people do not realize what an incredibly complex undertaking it was for the FCC to devise a new channel plan allocating the same number of broadcast licenses over at least seventeen fewer channels. There was a thread here a few years ago describing the technical obstacles that Baltimore WJLA-13 faces trying to maintain the western edge of its present contour in light of an adjacent channel problem that doing so would cause to reception of a channel 12 transmitter in Martinsburg which would not be obvious to any armchair pundits looking at the channel allocations.

The FCC has models calculating co-channel and adjacent channel interference that are about ten thousand times as complex as anything you can do in you head, so the only time the result will not tend to be optimal for the masses is when a station exercises its prerogative to keep its temporary assignment to incur a cost saving, be they capital costs or operating costs. Fortunately for me, I work and live in a large, lucrative television market (Washington/Baltimore), where only the MegaHertz stations are broke but have pulled off the transition anyway, so of the nineteen "full powered" analog stations stations we can normaly receive off-air, the only one whose reception will become "iffy" for a handful of the couple million people here might be the Baltimore analog MyTV-24, which broadcasts digitally on 41 and for some reason has been given really low power that will probably preclude people maybe ten to twenty miles south of Washington, DC from reliably receiving it.

We had similar threads in other DBS forums when DirecTV began operating its "Spot beams" for local-to-local carriage about five years ago. Everybody who was dissatisfied with some aspect of his own reception situation was sure he had a better way to do it, and everyone was wrong.

Fortunately for me, I work and live in a large, lucrative television market (Washington/Baltimore), where only the MegaHertz stations are broke but have pulled off the transition anyway, so of the nineteen "full powered" analog stations stations we can normaly receive off-air, the only one whose reception will become "iffy" for a handful of the couple million people here might be the Baltimore analog MyTV-24, which broadcasts digitally on 41 and for some reason has been given really low power that will probably preclude people maybe ten to twenty miles south of Washington, DC from reliably receiving it.
That would be the Fox owned WUTB-DT My 24 which is still at STA power of 530 watts at UHF 41. WUTB-DT is going to 200 kW, but with a new directional antenna with stronger power to the north. WUTB-DT was supposed to go full power last summer, but has been repeatedly delayed with reported build-out problems. The last report is that the hardware for full power operation is in place, but that they need to file license paperwork with the FCC first. The long drawn out process for WUTB is odd as it is a Fox owned station, they can't claim lack of money or resources for the delay in going full power on their digital channel.

I think this is a large part of what rrrrrroger is missing about the digital stations is that some are still at reduced power or currently operating from a side-mounted antenna that limits reception for people at the deep fringe. He needs to look up the situation with each station that he is not getting. And may have to go with a high mounted rooftop antenna setup.

I think this is a large part of what rrrrrroger is missing about the digital stations is that some are still at reduced power or currently operating from a side-mounted antenna that limits reception for people at the deep fringe. He needs to look up the situation with each station that he is not getting. And may have to go with a high mounted rooftop antenna setup.

Exactly right.

I've been posting online since 1988. I am hardly a "newbie". Most people do not realize what an incredibly complex undertaking it was for the FCC to devise a new channel plan allocating the same number of broadcast licenses over at least seventeen fewer channels. It would have been a lot easier if the FCC laid-down the rules very clearly:

- Analog stations will remain on their same assignments post-Feb 2009. (33 will be 33, 43 43, 45 45, et cetera.)
- Stations above 51 will be reassigned to lower "empty" slots.

The end. Then you'd have a "frequency map" identical to what had always existed, and had proven to be a working, real-world system. The FCC has models calculating co-channel and adjacent channel interference that are about ten thousand times as complex as anything you can do in you head, How do you know this? And may have to go with a high mounted rooftop antenna setup. Why should I spend $2-300 on an expensive roof setup, when ALL I'VE EVER USED it a cheap pair of rabbit ears for the last 35 years?

(Answer: Because the FCC picked a poor system to replace the superior easy-to-receive system.)

The FCC has models calculating co-channel and adjacent channel interference that are about ten thousand times as complex as anything you can do in you head, How do you know this?

Ok RRRRRoger - how do you know they DON'T !?!

Oh- would you be so kind as to post some tvfool.com pictures for your location ?
I'd suggest you do it as current analog, current digital, and post-transition digital, each as separate diagrams, since you get so many stations.

It would have been a lot easier if the FCC laid-down the rules very clearly:

- Analog stations will remain on their same assignments post-Feb 2009. (33 will be 33, 43 43, 45 45, et cetera.)
- Stations above 51 will be reassigned to lower "empty" slots.

The end. Then you'd have a "frequency map" identical to what had always existed, and had proven to be a working, real-world system. How do you know this? Why should I spend $2-300 on an expensive roof setup, when ALL I'VE EVER USED it a cheap pair of rabbit ears for the last 35 years?
Gee I guess we screwed up by not having you at the FCC:rolleyes: Do you really think that such a system would work? Fitting in a second channel for every TV station requires a great deal of coordination.

If you forced everyone to go back to their original channels you would be forcing every broadcaster to build something that they would be guaranteed to throw out after the transition.

You claim to be an engineer, but you've obviously never gotten past your rabbit ears. You should know that, while you may be content to watch a snowy picture, digital doesn't work that way. While you might be happy to pile up pennies on the pickup on you turntable, CDs don't work that way.

Many people on many different forum topics have tried to help you, but you always know better. Put your antenna outside (like many on this forum have tried to tell you) and quityerbitchin. Like that's ever going to happen....:(

How do you know this?
Read this.

http://www.fcc.gov/Bureaus/Engineering_Technology/Orders/1997/fc97115a.pdf

and

http://www.fcc.gov/Bureaus/Engineering_Technology/Orders/1997/fcc97115.pdf

The computer system is described on page 92. And read the footnotes.

So all digital will be on the UHF while VHF goes away? VHF is low power? I find it funny that ABC which has been VHF channel 7 is now UHF channel 38 for digital but the tv displays 07-01-02-03. Seams like all the digital stations below 9 are now high numbered UHF stations.

So all digital will be on the UHF while VHF goes away? VHF is low power? I find it funny that ABC which has been VHF channel 7 is now UHF channel 38 for digital but the tv displays 07-01-02-03. Seams like all the digital stations below 9 are now high numbered UHF stations.

No, VHF is not going away! Many stations will be in the VHF band after the transition as shown in the sticky thread at the top of the local reception forum. http://www.avsforum.com/avs-vb/showthread.php?t=823166

Info on DTV being on ch 2~51 post-transition is also included in the OTA reception FAQ sticky in this forum area :

http://www.avsforum.com/avs-vb/showthread.php?p=6650468&&#post6650468

---------

Roger "rabbit ears" might also want to read FCC's OET bulletin #69 available at following link as well as FCC's 2nd DTV review R&O(where the prodcedures/rulemaking for the channel election process for stations' post transition operation were described+put into place), which I posted a link to earlier in this thread :

http://www.fcc.gov/Bureaus/Engineering_Technology/Documents/bulletins/oet69/oet69.pdf

So all digital will be on the UHF while VHF goes away? VHF is low power? I find it funny that ABC which has been VHF channel 7 is now UHF channel 38 for digital but the tv displays 07-01-02-03. Seams like all the digital stations below 9 are now high numbered UHF stations.
Jeez...

All stations will brand themselves with their analog channel number, whether or not they use that physical channel for digital broadcasting.

Jeez...

All stations will brand themselves with their analog channel number, whether or not they use that physical channel for digital broadcasting.

Welcome to the tip of the ice berg! :)

Welcome to the tip of the ice berg! :)
OK, I'll bite. What's the rest of the story?

OK, I'll bite. What's the rest of the story?

We still have 9 months to go of questions!! ;)

If you forced everyone to go back to their original channels you would be forcing every broadcaster to build something that they would be guaranteed to throw out after the transition. Then what? Lots of stations are doing exactly that, and they don't seem to be bothered by it. 6, 8, 10,11, 12, 13, 15, 27..... all these stations in my local area are "throwing out" their temporarily assigned digital transmitters. Doesn't seem to bother them.


As for keeping all stations located in their present spots, it makes sense in a long-term perspective, because it means the frequency map post-2009 will be virtually identical to pre-1999. It would be neat & tidy.

We still have 9 months to go of questions!! ;)
:D
Hopefully some of the questioners will tire by that point. (I can dream, can't I?)

Then what? Lots of stations are doing exactly that, and they don't seem to be bothered by it. 6, 8, 10,11, 12, 13, 15, 27..... all these stations in my local area are "throwing out" their temporarily assigned digital transmitters. Doesn't seem to bother them.


As for keeping all stations located in their present spots, it makes sense in a long-term perspective, because it means the frequency map post-2009 will be virtually identical to pre-1999. It would be neat & tidy.

But it's not being forced on them. They have the option to keep their digital channel or change it based on a number of economic factors that you don't understand. Most of the reasons have been covered in this thread, so take your blinders off and read it again.

Then what? Lots of stations are doing exactly that, and they don't seem to be bothered by it. 6, 8, 10,11, 12, 13, 15, 27..... all these stations in my local area are "throwing out" their temporarily assigned digital transmitters. Doesn't seem to bother them.

Let me set ONE THING STRAIGHT. No station is "throwing out" anything as in they bought it new 3 years ago and it is now heading for the landfill. Many stations will be sending unused equipment to sister stations or they will sell it to other stations. The only thing headed to the landfill are analog transmitters that are at or beyond expected lifespan and there are many of those that stations have been nursing along for several years.

As for keeping all stations located in their present spots, it makes sense in a long-term perspective, because it means the frequency map post-2009 will be virtually identical to pre-1999. It would be neat & tidy.

You can't substitute apples for oranges and get the same taste. Analog and digital have different operating characteristics and therefore have different interference critia so unless a station would be willing to take a 50% coverage drop to maintain the same channel, something stations are not willing to do it didn't happen. It will NOT happen.

Time to move on to a new subject.

I don't understand why maintaining the pre-1999 frequency map would present any problems. Stations would have the same "problems" with neighboring stations they've always had.

But:

I know the post-2009 map certainly makes no sense. WBAL 11 in Baltimore has been forced to *reduce* coverage due to interference with a new channel 11 in Scranton PA that never exited before. (If that Scranton station had stayed on its old pre-99 frequency of 28, then the Baltimore station would not be having its current problems.)

I don't understand why maintaining the pre-1999 frequency map would present any problems. Stations would have the same "problems" with neighboring stations they've always had.

It has been explained several times to you. You don't get it. It appears you never will. Just accept it and move on. It is what it is.

I don't understand why maintaining the pre-1999 frequency map would present any problems. Stations would have the same "problems" with neighboring stations they've always had.

But:

I know the post-2009 map certainly makes no sense. WBAL 11 in Baltimore has been forced to *reduce* coverage due to interference with a new channel 11 in Scranton PA that never exited before. (If that Scranton station had stayed on its old pre-99 frequency of 28, then the Baltimore station would not be having its current problems.)

There's a thing called "interference agreement" that some stations have with one another. Sometimes there is just no other way to serve the public without it. There was interference before digital, and there will be interference after. We don't live in a "perfect world".;)

Perhaps but if I was the Baltimore 11 station manager, I'd be a lot happier if the Scranton station stayed on its old analog 28. That way I could maintain my same northward coverage that I've always had, rather than being forced to reduce it. I don't understand why maintaining the pre-1999 frequency map would present any problems.It has been explained several times to you. You don't get it. So far the only explanation I've received is "because", and that is not an explanation.

Perhaps but if I was the Baltimore 11 station manager, I'd be a lot happier if the Scranton station stayed on its old analog 28. That way I could maintain my same northward coverage that I've always had, rather than being forced to reduce it. So far the only explanation I've received is "because", and that is not an explanation.

That's because you refuse to read beyond "because". Your only argument seems to be to ignore the reasonable explanations that have been given here.

Perhaps but if I was the Baltimore 11 station manager, I'd be a lot happier if the Scranton station stayed on its old analog 28. That way I could maintain my same northward coverage that I've always had, rather than being forced to reduce it.

Based on their posted coverage areas, WBRE and WBAL never interfered with each other before, they don't now, and they will not interfere in the future. Stations are not "entitled" to any viewers that they happen to reach outside their coverage area. How did you determine that a Baltimore station will have to reduce its coverage because of a Scranton station?

Based on their posted coverage areas, WBRE and WBAL never interfered with each other before, they don't now, and they will not interfere in the future. Stations are not "entitled" to any viewers that they happen to reach outside their coverage area. How did you determine that a Baltimore station will have to reduce its coverage because of a Scranton station?
If I may provide a long answer. WBAL-DT NBC 11 is currently on UHF 52, but will move to VHF 11 next February after the analog shutdown. WBRE-DT NBC 28 is on VHF 11 at 30 kW ERP (Effective Radiated Power) and will stay there. So there is a possible co-channel interference, but WBRE-DT in Wilkes-Barre, PA which is well north of Baltimore (with a number of mountain ridges between them).

WBAL is currently at the maximum allowed power of 316 kW ERP for analog 11. To replicate that the coverage from the same height & antenna, the digital ERP should be somewhere in the range of 13.6 to 25 kW, give or take. However, so they can use their analog omni-directional antenna, WBAL-DT has filed and been granted approval to operate their DT 11 signal next year at 5 kW. See http://fjallfoss.fcc.gov/prod/cdbs/forms/prod/getattachment_exh.cgi?exhibit_id=624629 for their 301 attachment. Check pages 9 & 11. That document does show 0% interference with WBRE-DT, but 0.2% interference with WPVT-DT in Staunton, VA which is WBAL-DT's bigger interference concern. The filing shows WBAL's analog coverage as 8.11 million people but the proposed 5 kW DT 11 coverage as 7.45 million people. Unless WBAL-DT intends to file for increased power later this year when the FCC will revisit the issue, WBAL is one of the VHF stations that will have a reduced coverage area after the transition. So yes some of us have been looking at the nitty gritty details of what will happen next year, but unlike rrrroger, we are taking the time to understand the details. :D

Meanwhile, WJZ-DT CBS 13 will be at 28.8 kW on VHF 13 after they put up a new directional antenna with reduced power to the west.

WBAL is currently at the maximum allowed power of 316 kW ERP for analog 11. To replicate that the coverage from the same height & antenna, the digital ERP should be somewhere in the range of 13.6 to 25 kW, give or take. However, so they can use their analog omni-directional antenna, WBAL-DT has filed and been granted approval to operate their DT 11 signal next year at 5 kW. See http://fjallfoss.fcc.gov/prod/cdbs/forms/prod/getattachment_exh.cgi?exhibit_id=624629 for their 301 attachment. Check pages 9 & 11. That document does show 0% interference with WBRE-DT, but 0.2% interference with WPVT-DT in Staunton, VA which is WBAL-DT's bigger interference concern. The filing shows WBAL's analog coverage as 9.11 million people but the proposed 5 kW DT 11 coverage as 7.45 million people. Unless WBAL-DT intends to file for increased power later this year when the FCC will revisit the issue, WBAL is one of the VHF stations that will have a reduced coverage area after the transition. So yes some of us have been looking at the nitty gritty details of what will happen next year, but unlike rrrroger, we are taking the time to understand the details. :D
Thanks for the long answer. Always appreciated! I didn't know that WBAL requested reduced power to use their omni antenna.

It's amazing what a little thoroughness can dig up. So much for WBAL being "forced" to reduce power to avoid interference with Scranton.

Perhaps but if I was the Baltimore 11 station manager, I'd be a lot happier if the Scranton station stayed on its old analog 28. That way I could maintain my same northward coverage that I've always had, rather than being forced to reduce it. So far the only explanation I've received is "because", and that is not an explanation.

You need to go back up the thread where I explained how digital and analog are not an apples/oranges comparison and and there are different interference specifications that must be met for similar reception. You are just not listening because you don't want to. You don't understand, you are not trying to understand and there is your BECAUSE.

WBAL is currently at the maximum allowed power of 316 kW ERP for analog 11. To replicate that the coverage from the same height & antenna, the digital ERP should be somewhere in the range of 13.6 to 25 kW, give or take. However, so they can use their analog omni-directional antenna, WBAL-DT has filed and been granted approval to operate their DT 11 signal next year at 5 kW. See http://fjallfoss.fcc.gov/prod/cdbs/forms/prod/getattachment_exh.cgi?exhibit_id=624629 for their 301 attachment. Check pages 9 & 11. That document does show 0% interference with WBRE-DT, but 0.2% interference with WPVT-DT in Staunton, VA which is WBAL-DT's bigger interference concern. The filing shows WBAL's analog coverage as 8.11 million people but the proposed 5 kW DT 11 coverage as 7.45 million people. Unless WBAL-DT intends to file for increased power later this year when the FCC will revisit the issue, WBAL is one of the VHF stations that will have a reduced coverage area after the transition. So yes some of us have been looking at the nitty gritty details of what will happen next year, but unlike rrrroger, we are taking the time to understand the details. :D


Great answer, I definitely understand what is going on now, but one slight question, are we talking about Scranton, PA or Staunton, VA? Is there an interference issue between Staunton/Baltimore/Scranton? :D

Great answer, I definitely understand what is going on now, but one slight question, are we talking about Scranton, PA or Staunton, VA? Is there an interference issue between Staunton/Baltimore/Scranton? :D
I messed up the station call letters. The station is WVPT-DT PBS 51 in Staunton, VA in the Harrisonburg, VA DMA (#178) in the Shenandoah valley. WVPT-DT is currently on VHF 11 at 3.2 kW and will stay there post-transition.

The issue is that WBAL-DT is in between WVPT-DT at 165 miles to the SW and WBRE-DT at 134 miles to the north. Used the FCC TV Query website to look up distances from WBAL. The already crowded mid-Atlantic is just getting a little more packed.

That's because you refuse to read beyond "because". Your only argument seems to be to ignore the reasonable explanations that have been given here. "because digital is different from analog" is not an explanation. That's like when your kid asks, "Why is sky blue and grass green," and you answer "because sky is different from grass." That is a non-answer.

Try again please.

WHY can't post-2009 DTV channels be assigned the same frequency plan as existed with ATV channels pre-1999? Knowing that an antenna is an antenna, and does not care what kind of signal it's getting, it should not matter if the DTV frequency map was identical to the pre-1999 ATV map.

It would work.

It would be simpler.

How did you determine that a Baltimore station will have to reduce its coverage because of a Scranton station? The Baltimore station used to reach upto Harrisburg PA. And now, in order to avoid interference with Scranton, they've been forced to reduce power and can no longer be visible in Harrisburg after Feb 18, 2009.

Based on their posted coverage areas, WBRE and WBAL never interfered with each other before, they don't now, and they will not interfere in the future. Stations are not "entitled" to any viewers that they happen to reach outside their coverage area. How did you determine that a Baltimore station will have to reduce its coverage because of a Scranton station?

rrrrroger: Try reading this quote and answering this question first. See if it starts to sink in... WBAL was not "forced" to reduce power to avoid interference with WBRE. You haven't provided any source or reason for your conclusion other than your imagination.

Hint: The real reason is has already been given by afiggatt.

WHY can't post-2009 DTV channels be assigned the same frequency plan as existed with ATV channels pre-1999? Knowing that an antenna is an antenna, and does not care what kind of signal it's getting, it should not matter if the DTV frequency map was identical to the pre-1999 ATV map.

It would work.

It would be simpler.All the high UHF frequency stations whose frequencies are going away from the TV allocation would have to cease to exist.

WHY can't post-2009 DTV channels be assigned the same frequency plan as existed with ATV channels pre-1999?

There are at least three impediments that come to my mind, and people who are in the industry or who have studied the subject may well know even more:

1. (as MikeBiker beat me to posting) Channels with analog frequencies in the 52-69 range still have to relocate and their new locations have to be worked into the map.

2. The VHF-low band turned out not to carry digital signals so well, so many of the channels whose analog frequencies are on VHF-low want UHF or VHF-high frequencies for their DTV broadcasts.

3. Stations may balk at the effort and expense of moving their digital signals over to the former analog frequency when their digital broadcasts are already up and running on a different frequency.

As desirable as VHF-high frequencies seem to be, of the four VHF-high analog stations in Chicago, two are keeping their UHF digital frequencies, one is moving back to VHF-high (but that's partly because its current frequency is above 51, so it has to move, and the frequency it already has rights to is in VHF-high), and the other is still analog-only but will send its digital broadcasts, for reasons I don't understand, on a VHF-low frequency instead of the one it already has.

"because digital is different from analog" is not an explanation. That's like when your kid asks, "Why is sky blue and grass green," and you answer "because sky is different from grass." That is a non-answer.

Try again please.

WHY can't post-2009 DTV channels be assigned the same frequency plan as existed with ATV channels pre-1999? Knowing that an antenna is an antenna, and does not care what kind of signal it's getting, it should not matter if the DTV frequency map was identical to the pre-1999 ATV map.

It would work.

It would be simpler.

No, it wouldn't.

Do some reading in the Chicago OTA thread about the problems people have getting CBS (on channel 2 / 3). In general, ATSC and Low VHF do not work well together. You also got the spectrum auction - that reduced the channels available from 69 down to 51.

"because digital is different from analog" is not an explanation. That's like when your kid asks, "Why is sky blue and grass green," and you answer "because sky is different from grass." That is a non-answer.

Try again please.

WHY can't post-2009 DTV channels be assigned the same frequency plan as existed with ATV channels pre-1999? Knowing that an antenna is an antenna, and does not care what kind of signal it's getting, it should not matter if the DTV frequency map was identical to the pre-1999 ATV map.

It would work.

It would be simpler.

For starters, many of those channels are in the range above channel 52 which are going away, to be sold to telecom companies to improve your cell phone service, a major justification of the transition to digital.

Secondly, requiring a station to build a new facility to operate before the transition and then throw it out to convert to their original channel places an unnecessary financial burden on those stations. I work at station that is part of a large group. Our temporary assignment is above channel 52 and is going away We will go back to our original channel. All of the other stations in the group will remain at their new assignments. As a result our station has the highest conversion cost of the group, by far.

WHY can't post-2009 DTV channels be assigned the same frequency plan as existed with ATV channels pre-1999? Knowing that an antenna is an antenna, and does not care what kind of signal it's getting, it should not matter if the DTV frequency map was identical to the pre-1999 ATV map.

1) 52-69 is going away

2) 2-6 is the pits for DTV in urban areas

3) Stations that are happy to stay on their current DTV channel are not being forced to return to their analog channel, nor should they be.

4) Some stations moving back to analog channels are not able to replicate analog contours due to new interference projected on existing stations.

If DTV hadn't been running for the past 9 years and if DTV did not have any issues with Low-VHF and if our spectrum wasn't being raided, then maybe your solution would work. However, TV reception has always been a moving target and always will be.

rrrrroger: Try reading this quote and answering this question first. See if it starts to sink in... WBAL was not "forced" to reduce power to avoid interference with WBRE. They were forced by the FCC to have a smaller coverage area (analog 11 versus digital 11), thus making a station that was once visible in Harrisburg..... no longer visible post-2/18/2009.

WHY can't post-2009 DTV channels be assigned the same frequency plan as existed with ATV channels pre-1999? Knowing that an antenna is an antenna, and does not care what kind of signal it's getting, it should not matter if the DTV frequency map was identical to the pre-1999 ATV map.

It would work.

It would be simpler.All the high UHF frequency stations whose frequencies are going away from the TV allocation would have to cease to exist. As I explained previously, those stations above 51 would be reassigned to channels "in-between" the current allocations. So for example, there's space between channels 43 and 45 in the Baltimore-Philadelphia region. Channel 57 could be reassigned to 44 (while the other channels remain where they are).

That certainly makes more sense than the current arrangement where 45 is reassigned 46 and 43 becomes 47, while 57 becomes who knows what.

The FCC has just created a gigantic mess.

They were forced by the FCC to have a smaller coverage area (analog 11 versus digital 11), thus making a station that was once visible in Harrisburg..... no longer visible post-2/18/2009.
BULL$HIT! Just read the posts in this topic and you will find the reason. Of course, you won't believe it. You know everything.

As I explained previously, those stations above 51 would be reassigned to channels "in-between" the current allocations. So for example, there's space between channels 43 and 45 in the Baltimore-Philadelphia region. Channel 57 could be reassigned to 44 (while the other channels remain where they are).

What about WMCN-DT, which is already broadcasting on channel 44 in the Philadelphia area? Forgot about them?

That certainly makes more sense than the current arrangement where 45 is reassigned 46 and 43 becomes 47, while 57 becomes who knows what.

Channel 32, where they are already broadcasting DTV.


The FCC has just created a gigantic mess.
Yours would be worse. I Guar-on-tee it.

The FCC has just created a gigantic mess.

No. You're making a "gigantic mess" with filling these threads with comments that have been answered for you time and again, and you just won't accept the facts for what they are. Stop beating a DEAD HORSE!

What about WMCN-DT, which is already broadcasting on channel 44 in the Philadelphia area? Forgot about them? Nope. They would be returning to their original channel, thus making 44 open for use by analog-57 after 2009.

Nope. They would be returning to their original channel, thus making 44 open for use by analog-57 after 2009.

WMCN started out analog on channel 53 in Atlantic City, increased their DTV power and moved their antenna closer to Phili and then ceased analog broadcasting around 2002 because they now had cable coverage of the Phili market, something they had wanted to do for years but unable to as an analog station. After Feb 18, 2009 TV will only go from channel 2-51. There will be NO channel 53 for them to move back to. It is channel 44 for them or they go off the air.

The entire channel 52-69 block of frequencies have already been auctioned off to other spectrum users like public service and commercial WIFI companies who want use of those frequencies as soon as possible.