New to the board

[Tom_Ray]

Two issues that I continue to wonder about:

(1) Why do stations that format primarity talk or sports need digital at all? Neither format can benefit from increased bandwidth or stereo. Unless the occasional musical bed and / or stereo commercial is considered. Yet the HD radio I heard was playing a talk show, and it sounded most like medium-high bandwidth streaming. My ears are particularly sensitive to group delay / phase distortion, and I got listener fatigue in minutes and had to quit.

>>>> I use my father in law as an example. He has nerve damage from an on the job accident that resulted in his requiring rather extensive digitally controlled hearing aids. He has a hell of a time listening to AM radio in particular - he can't fully understand what is being said. And his favorite station is an AM talker (interestingly, he can understand FM stations quite well). The station went HD, so I got him an HD radio. This is the first time in ages he can understand the programming - I think it has something to do with the increased audio bandwidth and the sybillance sounds. And with the music bumpers and the amount of Broadway show spots WOR has, it really sounds much better than regular AM. RE the streaming quality - that is partially dependent on how the HD processing is set up (you need to be careful processing for codecs) and is a result of the data errors in the HD signal. One group I know has developed their own method of adjusting the HD equipment, and I think they are incorrect. they claim they can better determine data errors in the far field rather than measured at the transmitter monitor port. These stations tend to sound "streamy" to me.


(2) Why do people in the industry persist in saying most AM radios are limited bandwidth. I've done a reverse engineer on everything I have bought in the last five to seven years, and there is not a 3 to 4 kHz bandwidth AM to be found. They all are based on single IC's and have at most one very poor quality ceramic filter, that is wide as a barn door. If they even bother at all - I have found a few of them that just bypass the IF out - IF in connection with a capacitor, relying completely on the Q of the antenna and oscillator coil for their selectivity. I'd hardly call them superheterodynes. I had to go to a 20 year old radio to find one with three IF cans and 3 to 4 kHz bandwidth. Everything else is super wide bandwidth, horrible selectivity, and passes IBOC sidebands like high frequency rushing wind. Add the little 1 inch speaker which is a terrifically good tweeter, and very poor mechanical lash on the tuning dial, and you have a recipe for IBOC self-jamming. I was frankly apalled I spent up to $70 on these cheap, junky radios. Wideband - not for high fidelity, but because they are built shoddy. Yet - I continue to hear over and over again - that most AM radios are narrow bandwidth. Not true - I'd challenge anybody to go to Walmart and find an AM radio based on that antique reference design any more. Manufacturing costs and Chinese reference designs have won the market. A recipe for IBOC self jamming because its hard to get on frequency, and once you are, the 10 to 15 kHz sidebands scream at you like a thousand angry crickets.

>>>> Yet, I haven't experienced what you have described. I've put numerous radios on the bench, and if they don't cut off at 3.5-4K, the distortion figures are so high I find them unlistenable. Most of the radios I've tested have been car radios.


Tom Ray

 

[Tom_Ray]

Welcome to the board Tom. Good luck in the trenches

>>>>I brought my broom and fire hose - things should be just fine!

Tom Ray

 

[Chuck]

>>>>I brought my broom and fire hose - things should be just fine!

Tom Ray

Let me welcome you too. It is nice to get some real world experience reports. I've found that asbestos Jockey Shorts are very helpful. The Broom and fire hose will help too!

 

[radiopilot]

Welcome Tom,

As you can see the name calling has already started by the pro-HD crowd without benefit of your comments to those that replied to your post.

>>>> As long as it's somewhat good natured.....

Now that being said, you mentioned that you've been broadcasting HD on your AM station for five years... that would put that date to about 2002, if HD radios only came out as Mike has mentioned a year ago(which he's wrong) who then were you broadcasting to?

>>>> We were participating in testing with iBiquity at the time. We uncovered some issues with the codec, and proved that the system would work through a rather funky antenna system.


Was it experimental set-up of the transmitter and it's broadcasting scheme on the new HD system, were you broadcasting music, etc. What type of proof did you obtain by those listening that the signal was on par with the results you expected i.e.: who with an HD reciever called you on the status of the signal, what about people with analog receivers did they call your station to complain about noise and buzzing of their analog radios, and what did your staff do about any complaints?

>>>> The exciter we used was an exciter provided by iBiquity, along with their test radio, which was essentially a computer with the proper DSP boards installed. The testing was done with one of these radios in a specially outfitted van that was iBiquity's. The radio would output all types of data - audio frequency response of the analog and digital channels, data error rate, etc, and correlate this with a spectrum analyzer display. The data was quite complex and complete. We actually had 2 of the iBiquity radios - one at the transmitter, one at the studio. We only had a couple of complaints. One was from a guy who repaired analog radios from the 1930's - he called to tell us we had a hiss, and maybe we didn't know about it. We had another guy with a wideband radio in his 1980's era Jeep that was hearing hiss. These were the "normal" listeners who complained. When told what was going on, these listeners seemed satisfied that we were experimenting and thanked us for the explanation. The DX hobbyist complaints were another story.


Tom Ray

Tom

Thanks for the cordial reply...

You mentioned that the test radio was simply a computer with the dsp boards installed, would you actually say this is equivalent to today's HD radios being manufactured, and why only two radios? Shouldn't there have been many more test radios to get an accurate reading?

The persons you mentioned that complained about the hiss, isn't this what alot of people on these boards are complaining about when they say they are expeiencing hiss, almost like taking a shower with a mike being broadcast along with the carrier on the existing AM radios?

My co-worker where I work has a Sangean HDT-1 radio and he listens to FM-HD and I asked him to set it to AM -HD and as expected it sounds awful, why do some actually say this sounds great and others complain, I know this is asking too much of you since you can't really gaze into a crystal ball to figure this out?

Of course when they called the station to complain your staff told them you were doing experimental testing but they assumed the testing experimentation would either have corrected the hiss or stopped experimentation altogether to prevent further hiss... what did you do to take the hiss away?

I'm sure the DX'rs are coiled up and ready to blast HD proponents but they deserve at least some attention, they buy radios and tuners no different than the stations local listeners and they also listen to the advertisements as well so in essense they are 'captives' of the same broadcast as any listener in the protected area of the station, true or false?

Thanks for taking the time out... the trenches aren't as bad as you think!

Radiopilot

 

[davideduardo]

I'm sure the DX'rs are coiled up and ready to blast HD proponents but they deserve at least some attention, they buy radios and tuners no different than the stations local listeners and they also listen to the advertisements as well so in essense they are 'captives' of the same broadcast as any listener in the protected area of the station, true or false?

DXers are not, and have not been for 40 to 50 years, a significant part of the audience of any station. And even back in the 40's and early 50's, DX listening was only important to the 1-A clear channels and a few of the 1-Bs that put a good signal over a land area (many shoot over the ocean) like KOMA. So that means maybe 100 stations out of several thousand back then, and maybe a dozen today.

Otherwise, DXers listen mostly at night (where AM mostly is either not running spots or running bonus or barter spaots) and listen outside the metro area where 100% of station business comes from. The average listener to a "favorite" staiton spends 6 to 10 hours a week with it. How much time does a DXer spend with any one station? How many local merchants does that DXer patronize?

The DXing community is increasingly small (many good DX quality receivers have been discontinued of recent) but horribly noisy. They have become increasingly nasty in their dealings with stations to the point of wearing out their welcome at many stations; they oppose any change that affects their tiny hobby group to selfishly protect a hobby with a few thousand active participants, at most.

In other words, to answer your question, DXers deserve zero attention. And their attitude towards radio has changed so much that it makes me ashamed to have been a DXer for 45 years (the number of years I was a member of the National Radio Club, as well as several others).

 

[PocketRadio]

DXers are not, and have not been for 40 to 50 years, a significant part of the audience of any station.They have become increasingly nasty in their dealings with stations to the point of wearing out their welcome at many stations; they oppose any change that affects their tiny hobby group to selfishly protect a hobby with a few thousand active participants, at most. In other words, to answer your question, DXers deserve zero attention. And their attitude towards radio has changed so much that it makes me ashamed to have been a DXer for 45 years (the number of years I was a member of the National Radio Club, as well as several others).

"WSM-AM Tower Is Tall Symbol of History"

“When it was built, that was the time we upgraded our power to 50,000 watts, Allen says. And at that time, back in the ’30s, the station was picked up in Mexico, and almost two-thirds of the United States could pick up WSM. Today, it’s still huge. We cover 38 states from that tower... It’s just as effective – there really is no better technology than what we’re using now. And it’s 80-year-old technology.”

http://www.imagesbrentwood.com/culture/WSM-AM_Tower_Is_Tall_Symbol_of_History.php

You dismiss AM Dx'ers, but when AM-HD is turned on at night, you will see how many listeners are lost outside of protected contours. The broadscast industry, which has been stagnent for the past six years, in its rightous indignation, is trying to please Wall Street with this farce called HD Radio. I hope, that your rightous attitude is not typical of your industry, for if it is, I would be ashamed of being associated with it - it is no wonder, why TSL has dropped so dramatically, and that consumers have moved on to other technologies.

BTW, this is just a sampling of 50KW AM stations either ranked #1, or in the top-5:

WHO-AM News Talk Information 9.7 7.2 9.9 10.6
WLW-AM News Talk Information 8.9 9.9 11.2 9.8
WSB-AM News Talk Information 9.3 8.7 9.2 8.2
WGN-AM News Talk Information 5.3 5.5 5.8 5.4
WBBM-AM All News 4.2 4.1 4.4 4.6
WLS-AM News Talk Information 4.1 3.7 3.7 3.8
WTAM-AM News Talk Information 7.3 8.0 6.5 7.3
WJR-AM News Talk Information 4.8 4.9 5.3 5.3
KMOX-AM News Talk Information 8.4 7.7 8.2 8.4
KSL-AM News Talk Information 5.9 6.7 8.6 7.7

http://www.arbitron.com/radio_stations/home.htm

Good luck, with AM-HD.

 

[clouseau]

BTW, this is just a sampling of 50KW AM stations either ranked #1, or in the top-5:

WHO-AM News Talk Information 9.7 7.2 9.9 10.6
WLW-AM News Talk Information 8.9 9.9 11.2 9.8
WSB-AM News Talk Information 9.3 8.7 9.2 8.2
WGN-AM News Talk Information 5.3 5.5 5.8 5.4
WBBM-AM All News 4.2 4.1 4.4 4.6
WLS-AM News Talk Information 4.1 3.7 3.7 3.8
WTAM-AM News Talk Information 7.3 8.0 6.5 7.3
WJR-AM News Talk Information 4.8 4.9 5.3 5.3
KMOX-AM News Talk Information 8.4 7.7 8.2 8.4
KSL-AM News Talk Information 5.9 6.7 8.6 7.7

http://www.arbitron.com/radio_stations/home.htm

You do understand that these percentages are based on the metro areas and not nationally, right?

You understand when you post this, you MAKE a case for HD, right?

You understand that Cinncinatti stations get a 0.0 share in Washington DC , right?

Or are you asserting that these respectable numbers are improved by DX listening?

What exactly are you saying?

Clouseau

 

[R.F. Burns]

BTW, this is just a sampling of 50KW AM stations either ranked #1, or in the top-5:

WHO-AM News Talk Information 9.7 7.2 9.9 10.6
WLW-AM News Talk Information 8.9 9.9 11.2 9.8
WSB-AM News Talk Information 9.3 8.7 9.2 8.2
WGN-AM News Talk Information 5.3 5.5 5.8 5.4
WBBM-AM All News 4.2 4.1 4.4 4.6
WLS-AM News Talk Information 4.1 3.7 3.7 3.8
WTAM-AM News Talk Information 7.3 8.0 6.5 7.3
WJR-AM News Talk Information 4.8 4.9 5.3 5.3
KMOX-AM News Talk Information 8.4 7.7 8.2 8.4
KSL-AM News Talk Information 5.9 6.7 8.6 7.7

http://www.arbitron.com/radio_stations/home.htm

You do understand that these percentages are based on the metro areas and not nationally, right?

You understand when you post this, you MAKE a case for HD, right?

You understand that Cinncinatti stations get a 0.0 share in Washington DC , right?

Or are you asserting that these respectable numbers are improved by DX listening?

What exactly are you saying?

Clouseau

And are these 12+ numbers which mean nothing? A station doesn't sell 12+ numbers. What are the demographics? How does it do 18 to 24 or 24 to 54? Are the numbers tilted 55+? There's so much that these numbers don 't say. If for instance the audience is in one of the higher demographics that means that first the rate you charge per minute will be lower and second that your audience is dying off. THAT is why stations are moving towards digital. It's an attempt to improve the sound and make it acceptable to that younger demographic. You say who needs high fidelity talk, I say by going IBOC you'll have options outside of talk down the road.

 

[davideduardo]

BTW, this is just a sampling of 50KW AM stations either ranked #1, or in the top-5:

WHO-AM News Talk Information 9.7 7.2 9.9 10.6
WLW-AM News Talk Information 8.9 9.9 11.2 9.8
WSB-AM News Talk Information 9.3 8.7 9.2 8.2
WGN-AM News Talk Information 5.3 5.5 5.8 5.4
WBBM-AM All News 4.2 4.1 4.4 4.6
WLS-AM News Talk Information 4.1 3.7 3.7 3.8
WTAM-AM News Talk Information 7.3 8.0 6.5 7.3
WJR-AM News Talk Information 4.8 4.9 5.3 5.3
KMOX-AM News Talk Information 8.4 7.7 8.2 8.4
KSL-AM News Talk Information 5.9 6.7 8.6 7.7

Why do you keep posting 12+ listening estimates? Ratings (actually, shares) in 12+ is given away free on the web because it is valueless, meaningless and of no significance to the industry except for "photo op" bragging.

A station must have good ratings in the age span of 18 to 54 to get ad sales. One of the stations you mention, WGN, is not even in the top 20 stations in the sales demos.

Nearly every one of the stations you list is declining in revenue, some very fast.

The one that is not, KSL, is moving up. This is because of the fact you have conveniently omitted that KSL simulcasts on FM, and since they started doing that, they have increased the 18-54 (mostly 35-54) audience tremendously. At some point, like other Bonneville news talk stations WTOP and KTAR, they may move entirely to FM because analog AM does not attract many listeners in the sales demos. Of course, HD may offer hope to fidelity-challenged AM, and allow it to survive.

 

[davideduardo]

You dismiss AM Dx'ers, but when AM-HD is turned on at night, you will see how many listeners are lost outside of protected contours. The broadscast industry, which has been stagnent for the past six years, in its rightous indignation, is trying to please Wall Street with this farce called HD Radio. I hope, that your rightous attitude is not typical of your industry, for if it is, I would be ashamed of being associated with it - it is no wonder, why TSL has dropped so dramatically, and that consumers have moved on to other technologies.

Two or three or four more facts you conveniently ignore.

1. Radio sales is entirely in the local metro today. Nobody cares about listeners outside the metro.
2. Skywave reception takes place only at night, when AM radio listening is about 1/4 the daytime level.
3. Nearly all ad sales are in the 6 AM to 7 PM hours, by client instructions.
4. Only a few stations today benefit at all from skywave, due to the horrible interference on every channel from both domestic and foreign stations.

Night skywave is irrelevant today. It's the buggy whip of radio.

 

[PocketRadio]

The one that is not, KSL, is moving up. This is because of the fact you have conveniently omitted that KSL simulcasts on FM, and since they started doing that, they have increased the 18-54 (mostly 35-54) audience tremendously. At some point, like other Bonneville news talk stations WTOP and KTAR, they may move entirely to FM because analog AM does not attract many listeners in the sales demos. Of course, HD may offer hope to fidelity-challenged AM, and allow it to survive.

"KSL still No. 1 in ratings, but lead is dwindling"

"Remember the huge lead KSL (AM-1160/FM-102.7) had after simulcasting on FM? That's gone, and although the station holds No. 1 firmly, its outrageous advantage has vanished."

http://findarticles.com/p/articles/mi_qn4188/is_20060127/ai_n16039849

So much for simulcasting !

 

[radionekkid]

The trouble is you cant separate the physical properties of skywave effects from ground wave. It not so much about how much interference it causes, but how it is affected by interference coming in. You see, am digital radio works fine in the middle of the day. But as critical hours advance, digital reception begins to blend back and forth until it is not tolerable by average radio listener and average radio listener will not tolerate much today. The bar is set too high now and attention span too short. Clear channel radio stations are more tolerant of it because there is relatively low rss from other stations in critical hours and night hours. Regional stations, what they now call class b is much worse because rss is as much as an order of magnitude worse than clear channel station. 50kw station adjacent channel power is about 1200 watts on each side with digital in operation. At night and in critical hours, this will have an impact and will also vary from station to station depending on soil conductivity and geographic area of the specific market. Rss is root sum square of interfering skywave signals impacting a specific contour or signal level of subject station. This parameter vary widely from station to station on class b.

In my observation, these radios have issues even in moderate selective fades or phase cancellation where part of bandwidth is cancelled and spectrum becomes unbalanced. On channel background hiss gets worse during this condition and is function of this condition this is very evident on radios in analog caused by selective fade and in null structure of directional antenna where sidbands aree not balanced. This may be able to be helped to some degree in the radio by attempting to balance it out, but will drive up cost of radio causing other problems with marketing of them.

That’s the problem, is how much interference it can tolerate from reception standpoint. As to if it will be successful, the market place will ultimately and decisively decide this question. Yes, there are problems as there were problems from the beginning of broadcasting, time will resolve this and life will go on as usual as technology will catch up. I enjoy the lively discussion, but not the bombastic replies.

Thank you.

Old time, long retired engineer.

 

[davideduardo]

"KSL still No. 1 in ratings, but lead is dwindling"

"Remember the huge lead KSL (AM-1160/FM-102.7) had after simulcasting on FM? That's gone, and although the station holds No. 1 firmly, its outrageous advantage has vanished."

So much for simulcasting !

Who cares who leades in 12+, the only numbers you have access to. KSL has grown significantly in 25-54, mostly due to the FM addition and the simulcast. In 12+, Winter, the last published book, had the second highest ratings of the last 10 years, and Summer of '06 the third highest. In fact, on a 4 book average, KSL has never been higer than now... they have increased share immensely, and increased 25-54 dramatically. Who cares if the difference between them and other stations diminishes as long as KSL's CPP remains the same or gets better? That article is stupid and misses the entire purñpose of ratings... to create value for your airtime sales.


It would not surprise me if they eventually move KSL entirely to FM, and maybe do sports on AM, like they did in Phoenix.

 

[Tom_Ray]

You mentioned that the test radio was simply a computer with the dsp boards installed, would you actually say this is equivalent to today's HD radios being manufactured, and why only two radios? Shouldn't there have been many more test radios to get an accurate reading?

>>>> I'd say the radio was an ancestor of what you have today. These radios were far more complex than what you can buy in Walmart, and output a ton of data about the signal. We had two radios at WOR - one at the transmitter, one at the studio - for monitoring purposes. The iBiquity test van had several of these radios installed, in addition to numerous "normal" radios, both of the car and home/portable variety. All of the radios had been modified, and numerous parameters were logged, in addition to audio recordings made off of all the radios simultaneously, in addition to spectrum analyzer data that was being recorded. It was quite the site. Funny story: I drove around in the van with iBiquity for a week when we did overnight testing. We would usually hit the Queens/Midtown tunnel around shift change at midnight, so we'd have to wait at the toll booth for the shifts to change. So here were two guys, after midnight, in a non-descript, unmarked van, with an ungodly glow from all the computer monitors in the back and several antennas on the roof. And not one person at the toll plazas - cops included - asked what we were up to. And this was after 9/11. Go figure.


The persons you mentioned that complained about the hiss, isn't this what alot of people on these boards are complaining about when they say they are expeiencing hiss, almost like taking a shower with a mike being broadcast along with the carrier on the existing AM radios?

>>>> I believe so. And here's the issue. I've played with many "standard" AM radios, and have yet to get one to hiss on any of the NYC HD AM's. So I don't know if we're doing something right and other stations are doing something wrong, or what.

My co-worker where I work has a Sangean HDT-1 radio and he listens to FM-HD and I asked him to set it to AM -HD and as expected it sounds awful, why do some actually say this sounds great and others complain, I know this is asking too much of you since you can't really gaze into a crystal ball to figure this out?

>>>>> Right now, there tends to be a great difference in performance from station to station. I think part of it has to do with the audio processing on the HD channel - processing for codecs is considerably different than an uncompressed analog channel. Additionally, some of these stations may not have all the setup adjustments correct. I've been able to get WOR to "gargle" if I offset certain parameters, as the transmitted data errors in the signal increase and the codec in the radio has a hard time maintaining lock.


Of course when they called the station to complain your staff told them you were doing experimental testing but they assumed the testing experimentation would either have corrected the hiss or stopped experimentation altogether to prevent further hiss... what did you do to take the hiss away?

>>>>> All the complaints we had involved either wideband radios or analog tuned radios (ie, slug tuned, capacitor tuned, but not digitally tuned). In the case of the wideband radios, there wasn't much we could do about that. In the case of the manually tuned radios, tuning to the exact center of the frequency minimizes or eliminates the hiss. The persons involved generally went away happy - they either had a somewhat fix, or knew what was going on, and that's all they wanted.

I'm sure the DX'rs are coiled up and ready to blast HD proponents but they deserve at least some attention, they buy radios and tuners no different than the stations local listeners and they also listen to the advertisements as well so in essense they are 'captives' of the same broadcast as any listener in the protected area of the station, true or false?

>>>>> Since we sell to the local market - how many of those DXers are going to come to NYC and go to a Broadway show we advertise? How many are going to come in and go to Trattoria Dopo Teatro on 43rd? How many will have lunch at Sardi's? Probably not a one. When we sell the station, telling the guy at Trattoria about the number of listeners and potential listeners in the NY/NJ/Connecticut area that will hear his spot means a lot. He couldn't care less about someone in Ohio hearing his spot - they won't be inclined to hop the next train into town and possibly stop by his establishment because they heard the spot and our Food guy talk about them. From the station's standpoint, it's all about the local area. That's where our paychecks come from.

Tom Ray

 

[raydofan]

Hi Tom-

What would the impact be on AM radio to switch to digital completely (with a schedule as with HD-TV-so we're told), with the digital information placed where the analog currently rides on the carrier? Would it sound as good as FM? What are the DX implications?

(not sure if you can answer this, but...)

Is there any plan to move AM stations to any of the vacated VHF frequencies once TV moves to a strictly digital platform?

 

[dbdigital]

Hi Tom,

Things getting a little quiet over at the AMS board?

This talk by iBiquity of eventually splitting HD-AM into two digital program streams, have you looked into this at all? Can this be done and still fit an analog channel and data streams into the narrow bandwidth of an AM channel or would this spill over into the first adjacents and by how much? What kind of audio quality are we looking at for the digital channels?

Thanks.

db

 

[Mike Walker]

My guess would be that AM can never sound QUITE as good as the FM system, because AM stations will still be 10khz apart, vs. the 200khz for FM stations! FM will ALWAYS have more available bandwidth, whether there's an analog component or not. And there WILL be analog for the rest of most of our lives. These transitions take a long, long time.

 

[radiopilot]

You mentioned that the test radio was simply a computer with the dsp boards installed, would you actually say this is equivalent to today's HD radios being manufactured, and why only two radios? Shouldn't there have been many more test radios to get an accurate reading?

>>>> I'd say the radio was an ancestor of what you have today. These radios were far more complex than what you can buy in Walmart, and output a ton of data about the signal. We had two radios at WOR - one at the transmitter, one at the studio - for monitoring purposes. The iBiquity test van had several of these radios installed, in addition to numerous "normal" radios, both of the car and home/portable variety. All of the radios had been modified, and numerous parameters were logged, in addition to audio recordings made off of all the radios simultaneously, in addition to spectrum analyzer data that was being recorded. It was quite the site. Funny story: I drove around in the van with iBiquity for a week when we did overnight testing. We would usually hit the Queens/Midtown tunnel around shift change at midnight, so we'd have to wait at the toll booth for the shifts to change. So here were two guys, after midnight, in a non-descript, unmarked van, with an ungodly glow from all the computer monitors in the back and several antennas on the roof. And not one person at the toll plazas - cops included - asked what we were up to. And this was after 9/11. Go figure.


The persons you mentioned that complained about the hiss, isn't this what alot of people on these boards are complaining about when they say they are expeiencing hiss, almost like taking a shower with a mike being broadcast along with the carrier on the existing AM radios?

>>>> I believe so. And here's the issue. I've played with many "standard" AM radios, and have yet to get one to hiss on any of the NYC HD AM's. So I don't know if we're doing something right and other stations are doing something wrong, or what.

My co-worker where I work has a Sangean HDT-1 radio and he listens to FM-HD and I asked him to set it to AM -HD and as expected it sounds awful, why do some actually say this sounds great and others complain, I know this is asking too much of you since you can't really gaze into a crystal ball to figure this out?

>>>>> Right now, there tends to be a great difference in performance from station to station. I think part of it has to do with the audio processing on the HD channel - processing for codecs is considerably different than an uncompressed analog channel. Additionally, some of these stations may not have all the setup adjustments correct. I've been able to get WOR to "gargle" if I offset certain parameters, as the transmitted data errors in the signal increase and the codec in the radio has a hard time maintaining lock.


Of course when they called the station to complain your staff told them you were doing experimental testing but they assumed the testing experimentation would either have corrected the hiss or stopped experimentation altogether to prevent further hiss... what did you do to take the hiss away?

>>>>> All the complaints we had involved either wideband radios or analog tuned radios (ie, slug tuned, capacitor tuned, but not digitally tuned). In the case of the wideband radios, there wasn't much we could do about that. In the case of the manually tuned radios, tuning to the exact center of the frequency minimizes or eliminates the hiss. The persons involved generally went away happy - they either had a somewhat fix, or knew what was going on, and that's all they wanted.

I'm sure the DX'rs are coiled up and ready to blast HD proponents but they deserve at least some attention, they buy radios and tuners no different than the stations local listeners and they also listen to the advertisements as well so in essense they are 'captives' of the same broadcast as any listener in the protected area of the station, true or false?

>>>>> Since we sell to the local market - how many of those DXers are going to come to NYC and go to a Broadway show we advertise? How many are going to come in and go to Trattoria Dopo Teatro on 43rd? How many will have lunch at Sardi's? Probably not a one. When we sell the station, telling the guy at Trattoria about the number of listeners and potential listeners in the NY/NJ/Connecticut area that will hear his spot means a lot. He couldn't care less about someone in Ohio hearing his spot - they won't be inclined to hop the next train into town and possibly stop by his establishment because they heard the spot and our Food guy talk about them. From the station's standpoint, it's all about the local area. That's where our paychecks come from.

Tom Ray

Tom,

Thanks for your excellent response...

Sounds like you did some very good testing and looks like the results were in line with what I've or any engineer would have done. Funny you should mention the 'van with antennas' and how suspicious that must have looked after 9/11, when I worked for Pratt & Whitney back in the 1980's we were sent to 5 countries in Europe (U.S. Air force installations and NATO countries that bought the F-16 and F-15 aircraft) on the F100 engine's 'Full Authority Digital Electronic Control - FADEC system' and it consisted of a van full of test equipment to monitor and set the fuel control for the engine, well when we crossed the border from France to Spain on our next assignment we were met with the Basque Resistance and they arrested all of us (5 in our group and I was the Spanish speaking one) for being 'spies' and took us into their jail under machine gun point, we stood in their jails with $50,000 ransom until I was able to get a Spanish lawyer to call our American Consulate and have United Technologies Company (Pratt & Whitney mother corporation) lawyers settle the situation that we were not spies and that our equipment and mission was to monitor the FADEC system on the F-16 airplanes... It was horrible and the thought that these Basque's could have executed us as spies went through all our heads for 5 days we stood in their jail. Lo and behold we were freed and on our way to Barcelona.

You mentioned that all the standard radios you've used in the NYC area don't have the hiss, could this be a result of you being in a very good proximity to the broadcast signal and thereby would never experience the hiss while someone with a standard radio say 5-15 miles away in a different location may experience so much hiss that it's unbearable to the point of either changing the station or going off the band altogether?

I think you are right about the stations all processing their equipment differently and the reasons many experience different listening results as I have and surely many others across the U.S. So as you say one small setting and the codec turns to hash, could it be that maybe Ibiquity needs to have a seminar for the broadcast engineers on the proper setup and use of the equipment and problems expected with the transmission of the HD signals... I'm sure they already have such seminars and classes.

All the complaints you said were from 'wideband' or analog tuned radios, but isn't perhaps millions of these radios out there being used daily? The manually tuned radios constantly do go out of tune so there would be constant hissing as my Grundig radio does... doesn't mean I'm de-commissioning that radio in favor of another... Digitally synthesized radios are another matter as they stay locked into the signal and stay locked on so in this sense they are better at preventing hiss, I agree with you.

Funny you should say that... Do you know of a 'Mars Restaurant' in NYC?
This advertisement was heard by me when I was in Fredericksburg, Virginia during one of my assignments on a NYC station and I vowed to visit this restaurant on my next trip to NYC, YES I did go... and to many other places I've DX'd on the radio, how else would anyone know about anything going on in other cities? I'm not saying this is the norm but many DX'rs do this.

I'll agree with you on the 'paychecks coming in from the locals' but you really can't discount the other 'outside' the contour listening for increased sales to these businesses.

Tom, once again you've given us some good insight and we all appreciate your honesty and experience...


Radiopilot

 

[Tom_Ray]

Hi Tom-

What would the impact be on AM radio to switch to digital completely (with a schedule as with HD-TV-so we're told), with the digital information placed where the analog currently rides on the carrier? Would it sound as good as FM? What are the DX implications?

(not sure if you can answer this, but...)

Is there any plan to move AM stations to any of the vacated VHF frequencies once TV moves to a strictly digital platform?

What would the impact be on AM radio to switch to digital completely (with a schedule as with HD-TV-so we're told), with the digital information placed where the analog currently rides on the carrier? Would it sound as good as FM? What are the DX implications?

>>>> The major impact is that, obviously, the analog goes away. Moving the digital carriers into the analog area would allow the transmitted power levels of the digital components to be increased dramatically, resulting in a more robust signal, with increased coverage. The data rate, to my knowlege, would still be 36KB for the AM signal, as there isn't that much room. When you say "would it sound as good as FM", I assume you are referring to analog FM? In my opinion, if the processing is done correctly and the system is installed correctly, at present it sounds as good as FM. I think many normal listeners would also agree. While it may be possible to DX an HD signal (and I have had a couple of people do that with our signal), this tends to be a crap shoot, as the components of the HD signal tend to get jumbled by phase distortion under skywave conditions and therefore won't decode properly.

Is there any plan to move AM stations to any of the vacated VHF frequencies once TV moves to a strictly digital platform?

>>>>> The soon to be vacated VHF frequencies are not up for grabs by AM broadcasters or any broadcaster for that matter. They are being reallocated for "other services" and public service frequencies (ie, the cops, etc).

Tom Ray

 

[Tom_Ray]

Hi Tom,

Things getting a little quiet over at the AMS board?

This talk by iBiquity of eventually splitting HD-AM into two digital program streams, have you looked into this at all? Can this be done and still fit an analog channel and data streams into the narrow bandwidth of an AM channel or would this spill over into the first adjacents and by how much? What kind of audio quality are we looking at for the digital channels?

Thanks.

db

Things getting a little quiet over at the AMS board?

>>>>> I don't know....I haven't had the time to peruse it for several months :-0

This talk by iBiquity of eventually splitting HD-AM into two digital program streams, have you looked into this at all? Can this be done and still fit an analog channel and data streams into the narrow bandwidth of an AM channel or would this spill over into the first adjacents and by how much? What kind of audio quality are we looking at for the digital channels?

>>>>> 36KB is still 36KB, so yes, it will still fit in the allocated space. However, the main HD channel would then become 50-15kHz mono, 20KB, with the remaining channel to be 12-16KB. It would be good for a voice channel, ie, reading for the blind or something like that. Of course, as things progress and codecs continue to improve, someone will figure out a way to cram a higher quality signal into that 12-16KB space.

Tom Ray