AM IBOC at Night

[mgpt6]

It should be this month that nighttime IBOC for AM is turned on. Dont think that Disney 1260 or WXKS -AM 1430 will have much affect in Boston. However , WBZ 1030 turning IBOC on , will mean no more night time reception of KDKA 1020. Also , not sure if 1010 WINS or 1050 from NYC will be received at night any more. Also, what affect will WCBS 880 NYC have on ESPN890 here in Boston?

 

[Neggy]

I don't know how many of you "DX", but when I am on my way to work in the pre sunrise hours, I will punch up and down the AM dial and listen to radio from far away places, and imagine this is what was done back in the days before TV, coast to coast feeds, satellites, and the internet made the world a smaller place.

I listen to WINS out of NYC on 1010 which will probably get burried by BZ's IBOC.
I listen to WABC sometimes too. WBAL out of Baltimore comes in like a local on 1090.

There are other stations that I will stop and listen to until I hear a legal ID or a spot that will give me an idea where the station is.

Back in the early 70's, I made a 5 tube super-hetrodyne radio from scratch. From the aluminum box, tube sockets, coils, cans, caps and assorted other components I made a nice radio with a great RF section. I took that radio with me to 48 states where I would sit outside at night with a length of wire as my antenna and my tuning coil adjustment tool I would search for distant signals,especially WBZ. If I could get BZ I could get local news from home. This was 20 years before Boston.com. I miss those days.

 

[pqgeorge]

It should be this month that nighttime IBOC for AM is turned on. Dont think that Disney 1260 or WXKS -AM 1430 will have much affect in Boston. However , WBZ 1030 turning IBOC on , will mean no more night time reception of KDKA 1020. Also , not sure if 1010 WINS or 1050 from NYC will be received at night any more. Also, what affect will WCBS 880 NYC have on ESPN890 here in Boston?

Once the IBOC is on at night, it will have a cumulative effect with interference. For example, if a full analog station is abutted with two IBOC stations, you can bet that the analog station will be in the mud (or shall I say, quicksand) with skywave interference. You more than likely won't hear it again. I, too, am a regular listener to 1010/WINS, not specifically because it's a DX station, but because I find them to be very concise with the news. It's a great station. And I love listening to "Dr. Knowledge" on KDKA/1020 on the weekends as well, on my way home from New Hampshire. But alas, the IBOC will effectively kill that. There will be some interference with ESPN/890 from WCBS during nighttime due to skywave's propagation characteristics. Unfortunately, it's the nature of the beast. I actually have a Boston Acoustics HD Radio. On the FM, it's pretty good. On the AM, it's numb..... even with a longwire antenna. I don't even bother with the AM side of it, anymore (and I'm in WBZ's backyard). They say that this is "progress". I don't think that will be the case with AM IBOC. I guarantee, the day the IBOC goes 24/7, the FCC and the AM stations are going to be deluged with interference complaints. And these will not all be from DX'ers. (Soapbox mode off.)

 

[webcastboy]

Peter - don't judge AM IBOC by the Boston Acoustics Receptor HD alone...it's well-known to be rather "deaf" on AM. Conventional wisdom is that the plasma display generates interference to itself, especially on AM. I have had my hands on a half-dozen different IBOC tuners now, and there are units out there that get AM much better.

I don't really DX much, although I do think it's cool when I catch a distant station. But I think y'all are forgetting something about IBOC, especially on AM: the signal reception is FAR more consistent across the local service area. If you haven't had a chance, I highly recommend finding the articles Michael LeClair has done for Radio World Engineering Extra about his experiences with AM IBOC on WBUR 1240 down on the Cape. He's reporting that where their analog signal could be considered "solid" until perhaps the 2.5 or 3 mV/m range...the IBOC signal is "solid" out to 0.75 to 1mV/m range. That's a GIGANTIC improvement. So while the DX'ing opportunities will fade...the improvements for LOCAL reception will improve significantly.

Plus, it's hard to overstate the difference in what "solid" is on IBOC...once you get used to the audio just being hiss, click, fade and pop free...it's quite jarring to go back to analog. That's not something that'll sell receivers...but it will make listeners happy that they bought the receivers, after the fact.

And this is ignoring the inherent improvements in audio quality for AM IBOC, too.

Granted, since the digital signals are still carriers on the analog wave, the signal is still susceptible to interference sources...overhead power transmission lines (the big ones, not the local street wires) are a good example. But typically the interference is there for a few seconds as you drive past and then it's gone. Ironically while the time spent listening to interference is probably less...I'd wager it's more noticeable because you're not used to unconsciously filtering out the noise.

BTW Peter, I'll challenge that guarantee...I know several engineers that braced for listener complaints when they turned on their AM IBOC's for daytime only, and many of them got ZERO complaints. A few got a handful (less than five) complaints, and perhaps one or two got a rash of griping (more than ten complainers). If it didn't happen when AM IBOC first showed up, I seriously doubt it's going to get markedly worse when nighttime IBOC comes around.

I'll also add that it's only a matter of time before you see distant stations renting multicast channels on local FM signals...so perhaps you'll hear WINS 1010 without the hassle of DX'ing!

 

[pqgeorge]

Peter - don't judge AM IBOC by the Boston Acoustics Receptor HD alone...it's well-known to be rather "deaf" on AM. Conventional wisdom is that the plasma display generates interference to itself, especially on AM. I have had my hands on a half-dozen different IBOC tuners now, and there are units out there that get AM much better.

I don't really DX much, although I do think it's cool when I catch a distant station. But I think y'all are forgetting something about IBOC, especially on AM: the signal reception is FAR more consistent across the local service area. If you haven't had a chance, I highly recommend finding the articles Michael LeClair has done for Radio World Engineering Extra about his experiences with AM IBOC on WBUR 1240 down on the Cape. He's reporting that where their analog signal could be considered "solid" until perhaps the 2.5 or 3 mV/m range...the IBOC signal is "solid" out to 0.75 to 1mV/m range. That's a GIGANTIC improvement. So while the DX'ing opportunities will fade...the improvements for LOCAL reception will improve significantly.

I think for the time being, that may be the case. But, when other stations on 1240 (a "Graveyarder", mind you) go IBOC, that extended coverage will be lost due to the eventual umpteen stations on 1240 with IBOC at night that will pretty much put the WBUR/1240 back into the mud and limit the local reception.

Plus, it's hard to overstate the difference in what "solid" is on IBOC...once you get used to the audio just being hiss, click, fade and pop free...it's quite jarring to go back to analog. That's not something that'll sell receivers...but it will make listeners happy that they bought the receivers, after the fact.

And this is ignoring the inherent improvements in audio quality for AM IBOC, too.

I don't know. IMHO: The sound of AM-IBOC seems a little brash to me, kind of "tinny".

Granted, since the digital signals are still carriers on the analog wave, the signal is still susceptible to interference sources...overhead power transmission lines (the big ones, not the local street wires) are a good example. But typically the interference is there for a few seconds as you drive past and then it's gone. Ironically while the time spent listening to interference is probably less...I'd wager it's more noticeable because you're not used to unconsciously filtering out the noise.

BTW Peter, I'll challenge that guarantee...I know several engineers that braced for listener complaints when they turned on their AM IBOC's for daytime only, and many of them got ZERO complaints. A few got a handful (less than five) complaints, and perhaps one or two got a rash of griping (more than ten complainers). If it didn't happen when AM IBOC first showed up, I seriously doubt it's going to get markedly worse when nighttime IBOC comes around.

No problem, challenge accepted (of course on a gentleman's bet). Drop me a line and let's shake on it.

I'll also add that it's only a matter of time before you see distant stations renting multicast channels on local FM signals...so perhaps you'll hear WINS 1010 without the hassle of DX'ing!

I don't consider listening to a DX station to be a hassle for me. On the contrary, it adds a certain flavor to the reception of that station. I know, it's the DX'er in me. Oh, well..... I still think analog audio will always have that certain "warmth" that digital could never touch.

 

[webcastboy]

I don't know. IMHO: The sound of AM-IBOC seems a little brash to me, kind of "tinny".

No arguments here, I just find the expanded auditory bandwidth (and stereo sound) to been "better sounding" than analog AM...but that's me. I don't deny that AM IBOC does have some digital compression crunchiness, although a lot of that can be compensated for by the station using the right audio processing. The pre-correction that can happen these days is amazing.

Of course, there's also the irony that the HDC codec for IBOC is better for music than voice at low bitrates, so while analog AM has survived mostly on talk/voice, IBOC AM will survive better with music.

I think for the time being, that may be the case. But, when other stations on 1240 (a "Graveyarder", mind you) go IBOC, that extended coverage will be lost due to the eventual umpteen stations on 1240 with IBOC at night that will pretty much put the WBUR/1240 back into the mud and limit the local reception.

I won't talk in absolutes, but based on the research I've seen...I am reasonably confident that this will not be the case. It might be true if there are skywave issues on adjacent channel stations, but AFAIK those cases will be fairly rare. Don't discount how robust the IBOC signal is, the difference is not unlike analog vs. digital cellphones (for those of you who remember how awful analog cellphones were).

FWIW, I do think that we may see a rash of problems at the beginning if the receivers aren't up to snuff and you have a much higher noise floor coupled with a lousy tuner. That I would almost categorize as "likely"...but again, we'll see that problem fixed relatively quickly as the OEM's adapt.

Meh, either way we'll find out pretty soon. There were a LOT of station owners that were waiting for nighttime authorization before they invested in IBOC...with that coming, there's suddenly a lot of AM IBOC plans being "spun up" as we speak.

 

[Eli Polonsky]

I'll also add that it's only a matter of time before you see distant stations renting multicast channels on local FM signals...so perhaps you'll hear WINS 1010 without the hassle of DX'ing!

In these days of tight budgets, what would make it worth the money for an out-of-market station to do that? Unless WINS gets their sales staff to solicit advertisers in the Boston area, I don't see why they would want to spend money to rent a multicast channel out here.

 

[w9wi]

It should be this month that nighttime IBOC for AM is turned on.

Best I can tell the IBOC rules have NOT yet been published in the Federal Register, which means blanket nighttime IBOC will NOT happen this month.

(I am quite surprised how long it seems to be taking to finish the formalities on this)

 

[Neggy]

this morning I was DXing just before 5 AM on 93 south at the NH line, and as I was bumping up from 680 heading to 770 to listen to WABC NYC I caught 760 WJR out of Detroit loud and clear.

I guess this won't be happening for much longer.

 

[DG02816]

A more interesting scenario will happen here in Philly when KYW 1060 lights up night IBOC. I think Scott Fybush spoke to this in a recent NERW; he mentions that KYW's transmitter site is 79 miles from WEPN's. Should be interesting what wall-to-wall digital hiss will do...WNYH 740 on Long Island is trying to slam its audio to the wall to be heard over the hiss from WOR 710 and WABC 770.

Dave Gardiner

WVCH 740/WNWR 1540

Philadelphia

 

[webcastboy]

In these days of tight budgets, what would make it worth the money for an out-of-market station to do that? Unless WINS gets their sales staff to solicit advertisers in the Boston area, I don't see why they would want to spend money to rent a multicast channel out here.

Admittedly WINS is a bad example. I'm thinking more along the lines of rimshot stations, or daytimer AM's, looking to get more solid coverage. It's already happening...for example, WXXI-FM HD3 is simulcasting WXXI-AM's NPR news/talk offerings to compensate for WXXI-AM's restricted nighttime pattern.

I could also see an enterprising owner trying to set up a regional network, or perhaps a strategic coverage of a corridor, like New Jersey between Philly and NYC, or along I-95 through Connecticut.