Whats going to happen with the old analog TV transmitters after feb 17-2009.

[CW]

So the question begs, if you were to put an IBOC type signal on a VHF or UHF frequency, without an analog compliment, and up to 4 streams of stereo content ... a) how much bandwidth would you need, b) how much separation would you need between stations on the same frequency, and c) how many channels separation would you reasonably need between local stations?

The RF bandwidth for an IBOC signal doesn't change whether hybrid or full-digital; they support more data payload by stuffing more carriers in the middle where the analog used to be. Looks to me like you could use alternate channels - 76.1, 76.5, 76.9, etc... I would figure 12MHz of bandwidth (two TV channels) would support 120 IBOC channels (actually I guess it wouldn't be "OC" anymore with the analog gone!) of which 60 could be used at any given site.

I've suggested elsewhere that TV channels 2-6 should be authorized for digital radio on a secondary basis to full-power DTV. Can't think of any market where you couldn't get at least two channels worth of radio spectrum and would imagine that in most, you could get all five. Butte, Montana is the only place where more than one low-band channel will be used for DTV after transition.

However, a lot of other folks forget the ANALOG LPs still left on lowband......I did a search on the FCC site...831 records for 2-6 LP analog....but some are dupes or weird (like a CP issued for Dallas and another issued for Arlington just west toward Ft Worth!!! AND to top it off, there are LD apps for 6 in Dallas and Mesquite (SE side of Dallas)!!!(
I can see 6 being used but I doubt 2-6 will be available totally...unless the FCC orders the LPs off the air...and that wont happen...(I can hearing the screaming now!)....

 

[WPPCProductions]

Thanks for all the info,Its a complete new learning experience on dtv now as it starting to sink into my head, ok as I was reading on the post-transition table of allotments list for here in Connecticut in New Haven Ch 6 Ch10 and ch39, I know ch10 is WTNH ch8 ch39 is ch59 replacement channel , ok now who is ch 6.

WEDY-DT, CPB, currently on 65 analog....Their CP was modified in 2002 for the DT6 and supposed to expire in 2005; guess it got extended....a whopping 400watts ERP but better coverage than the 7KW on 65!!! (More hams can generate more than 400w ERP on UHF amateur TV in the 420-440 ham band!)

Here is their proposed coverage on Channel 6 DT:
http://www.fcc.gov/fcc-bin/FMTV-service-area?x=DT596819.html

They get close to covering the Hamptons in NY....good for fund raising

thanks. I forgot about ch65.Wow 400watt erp, less power on the low band and gain
coverage and save on the electric bill too.

 

[w9wi]

However, a lot of other folks forget the ANALOG LPs still left on lowband......I did a search on the FCC site...831 records for

Looking at the top 10 markets, for LP stations analog or digital within 200km and FP DTVs within 400km:

NYC: channels 2 and 4 completely clear. Channels 3 and 6 used locally. Channel 5 has a CP for a 20-watt digital station 69km away. 2, 4, and probably 5 useful for radio.

LA: Channel 2: 3 LPTVs none closer than 135km. Nearest FPDTV in Las Vegas at 375km.
Channel 3: CP for local -LP with DTV app for same channel.
Channel 4: 3 LPTVs none closer than 123km.
Channel 5: 38-watt LPTV at 187km. App for a 500-watter at 142km. Low-power DTV app at 106km.
Channel 6: Many LPTV licenses, CPs, and apps analog and digital. Most more than 100km distant but one at 34km.

Channels 2, 4, and 5 probably useful for radio.

Chicago: Channels 2 and 3 completely open. Local LP-DTV apps on channels 4 and 6. FP-DTV on channel 5 176km away. 2 and 3 definitely useful; 5 might be useful for directional radio - and the null would be over Lake Michigan.

Philadelphia: channel 2 completely open. Channels 3, 4, and 5 have -LPs but none closer than 128km. 6 will be used by full-power local DTV. 2, 3, 4, and 5 should be useful for radio.

Dallas: channel 2 with LP licenses, CPs and apps but none closer than 121km. Channels 4 and 5 completely open. Local -LPs on 3 and 6. 2, 4, and 5 should be useful for radio.

San Francisco: Channel 4 completely open; 2, 3, 5, and 6 have -LPs but none closer than 136km. All five low-band channels should be useful for radio in San Francisco.

Boston: 4 and 5 completely open. 2 occupied by a -LP, but it's only four watts and 185km away. WEDY in Connecticut is only 193km away but it's also only 400 watts. Local -LP on channel 3. 2, 4, 5, and 6 should be useful for radio.

Atlanta: 2 completely open. 3 has an app for a 45kw FP-DTV but it's 389km away on the Florida Gulf Coast. Local -LPs on 4 and 6. Nearest 5 is a 14-watt translator 151km away. 2, 3, and 5 useful for radio.

Washignton: FP-DTVs on 3 (338km), 5 (295km), and 6 (194km). 60-watt LPTV on 4 at 162km. 2 completely open. 2 and 4 definitely useful for radio, probably 5 too because of the mountainous path to the FP-DTV.

Houston: Apps for LPTVs on 2, 4, and 6 all 180km away. 3 and 5 completely open. All five low-band channels should be useful for radio in Houston.

Looks to me like at least three low-band channels should be useful for digital radio in all top-ten markets. That's enough to give each existing analog FM station its own second channel for full-digital IBOC operation.

 

[FredRichards]

The only thing that bothers me about using 2-6 for radio services is that it can be prone to skip, as we both know, W9WI.

I was basing my channel 14-18 or so reasoning on the fact that most radio station owners care only for their grade A and partial B. So if you take, for example, any of the Nashville stations, most would be happy with a 40-45 mile contour around the city.

Perhaps the only complaint would be WSM which might want a larger profile. But from an engineering standpoint you could provide a fairly decent signal in that coverage to receivers, mobile and portable. Yet, you could also put another station on the same frequency 150-175 miles away.

The bottom line is making a service which would be spectrum efficient, yet deliver the content to the ears in the community with reasonable reliability. I think the low bands would be subjected to interference at certain parts of the year. In fact, it's going to be interesting to see what the results will be for any of the DTV stations on low band.

Of course this is all a dream since it seems that Ibiquity is wrecking the band before saving it, so this discussion might be moot. Oh well.

 

[w9wi]

The only thing that bothers me about using 2-6 for radio services is that it can be prone to skip, as we both know, W9WI.

Not as prone as 530-1710

I was basing my channel 14-18 or so reasoning on the fact that most radio station owners care only for their grade A and partial B. So if you take, for example, any of the Nashville stations, most would be happy with a 40-45 mile contour around the city.

Perhaps the only complaint would be WSM which might want a larger profile. But from an engineering standpoint you could provide a fairly decent signal in that coverage to receivers, mobile and portable. Yet, you could also put another station on the same frequency 150-175 miles away.

14-18, however, are not available in many (all?) Top 10 markets. They were reallotted for public-safety years ago.

I don't think anyone else would want 530-1710 (with the possible exception of hams) and even if such a new band were created tomorrow, there'd still be a BUNCH of 530-1710 receivers for years to come. So stations like WSM that want a large coverage area could leave their analog AM transmitters on for as long as desired. (indeed, pretty much *all* AM stations would probably leave their analog transmitters on for years to come)

the year. In fact, it's going to be interesting to see what the results will be for any of the DTV stations on low band.

Yes, it will. Our local CBS station just filed their permanent DTV facility: 10kw on channel 5. Time (a bit less than a year!) will tell.