AM HD TURNOFF PACE ACCELERATES

[davideduardo]

Does iBiquity get royalty fees when someone sells a car with an HD receiver? Are these enough to keep iBiquity solvent if terrestrial HD dries up?

iBiquity gets a royalty for each HD enabled chip sold.

HD terrestrial is apparently more solid than ever. The HD channels are being leased out for data, such as real time traffic reports, as well as all manner of ethnic and specialty programming.

The use of an HD-2 and beyond as a source to allow a major market translator is a very real benefit of HD; HD's don't count against the ownership cap, even with "big" translators such as several that are 250 watts at 1000 feet or more.

AM HD is not viable and looks like it will eventually disappear or only be used on the very big non-directional signals. But FM HD is very viable and is expanding.

 

[landtuna]

Ah. It seems reports of HD's death (on FM at least) are very premature.

 

[rbrucecarter5]

Ah. It seems reports of HD's death (on FM at least) are very premature.

If the secondary services are as unreliable as HD-2 is, I think those services will eventually disappear as well. The biggest problem I am seeing is LO jamming from radios as much as 100 feet away. Traffic can stand dropouts - my garmin uses HD for traffic - the traffic information is outdated and tells me why I am stuck in traffic. But ethnic listeners will get sick of dropouts, and dropouts on data services could be catastrophic to users of those services. To make matters worse - I think I am finding dropouts due to undertones of the LO as well as the LO itself - that - or low side injection is being used on some car radios. Either way, stations across the dial are subject to LO jamming from nearby cars, whether they have HD radios or not.

HD isn't ready for prime time. It never was. Bad engineering that forgot that first adjacent frequencies are already occupied - by fleeting reception of local oscillators in nearby radios. There is protection at 10.6 and 10.8 MHz difference in frequency. But HD, to be reliable, also needs protection at 10.4 and 11.0 MHz. Without it - HD drops. Unfortunately for me, there are popular stations that jam the HD-2's I like. Its not the radio, either, I observed an LO jamming event in another HD equipped vehicle just last night. This time is was from a neighbor, whose radio in their house tuned to 93.7 jammed HD on 104.1.

 

[Kelly A]

But ethnic listeners will get sick of dropouts, and dropouts on data services could be catastrophic to users of those services.

So now you're speaking on behalf of other cultural backgrounds Bruce? I get traffic updates via HD Radio on my GPS here in the DC area. It works quite well. In fact, I'd say the traffic info I get via HD to my GPS is more timely and accurate than waiting for WTOP's useless aural traffic reports.

To make matters worse - I think I am finding dropouts due to undertones of the LO as well as the LO itself - that - or low side injection is being used on some car radios. Either way, stations across the dial are subject to LO jamming from nearby cars, whether they have HD radios or not.

Here you go with the old school unsubstantiated observations and claims again. Local Oscillator issues between modern radios isn't a problem in a real world and for any practical measure. And I'd bet you have no backup for your statement, so I'm not going to bother asking how you arrived at that conclusion.

HD isn't ready for prime time. It never was. Bad engineering that forgot that first adjacent frequencies are already occupied - by fleeting reception of local oscillators in nearby radios. There is protection at 10.6 and 10.8 MHz difference in frequency. But HD, to be reliable, also needs protection at 10.4 and 11.0 MHz. Without it - HD drops. Unfortunately for me, there are popular stations that jam the HD-2's I like. Its not the radio, either, I observed an LO jamming event in another HD equipped vehicle just last night. This time is was from a neighbor, whose radio in their house tuned to 93.7 jammed HD on 104.1.

You might want to try catching up on modern HD Radio transmission techniques Bruce. Starting back in 2009, many stations running HD including NPR stations, are using asymmetrical IBOC. The reason is where a station may have first adjacent station concerns within their coverage area. Here is a link to how it works:
http://www.nautel.com/solutions/advanced-solutions/14db-10db/

Finally, your comments about IF protections for HD radio, is complete gibberish.

 

[landtuna]

If the secondary services are as unreliable as HD-2 is, I think those services will eventually disappear as well. HD isn't ready for prime time. It never was.

I don't know under what conditions you have problems with HD-FM but I have had exactly two. In the Phoenix metro area (a very large metro area) I lose my HD signal for a few seconds in the middle of a tunnel but it comes back again within seconds. I also lose it at a specific intersection which is adjacent to Scottsdale airpark. I suspect it is being killed by something emitting from the airpark. Other than that the signals are reliable and consistent to a distance of 50+ miles from Phoenix in multiple directions, two of which are mountainous.

I won't speculate on what is causing your problems but they are clearly not HD-wide.

 

[rbrucecarter5]

So now you're speaking on behalf of other cultural backgrounds Bruce? I get traffic updates via HD Radio on my GPS here in the DC area. It works quite well. In fact, I'd say the traffic info I get via HD to my GPS is more timely and accurate than waiting for WTOP's useless aural traffic reports.




Here you go with the old school unsubstantiated observations and claims again. Local Oscillator issues between modern radios isn't a problem in a real world and for any practical measure. And I'd bet you have no backup for your statement, so I'm not going to bother asking how you arrived at that conclusion.



You might want to try catching up on modern HD Radio transmission techniques Bruce. Starting back in 2009, many stations running HD including NPR stations, are using asymmetrical IBOC. The reason is where a station may have first adjacent station concerns within their coverage area. Here is a link to how it works:
http://www.nautel.com/solutions/advanced-solutions/14db-10db/

Finally, your comments about IF protections for HD radio, is complete gibberish.

Glad the HD traffic is working for you on Garmin, I would have assumed DC would have even less coverage because East Coast stations are relatively limited.

I will let you substantiate the claims. I assume you have a car with an HD radio, and a second car. Park them side by side and turn on an HD FM station on the upper half of the band. Turn on the radio in the other car and tune to a station anywhere from 10.4 to 11.0 MHz lower. HD absolutely WILL DROP. If you have someone who can drive the other car, or you can drive your HD equipped car while the other car's radio is left on - do a range test. You will find the LO jamming is from 30 to 100 feet. I've done this simple test half a dozen times - it works every time, and it will work for you.

LO protections are not gibberish. The existing ones are in place to give spacing between stations separated by 10.6 to 10.8 MHz. A good example is WWIA in Palm Bay on 88.5 - they got a protest from a station on 99.3 less than 20 miles away. They had to go way down on power before the FCC would sign off on the waiver of spacing rules. Now - with HD adding sidebands on adjacent frequencies, you have a whole host of new problems based on local oscillator images. If you haven't done the test I suggested - please don't call this unsubstantiated and gibberish because it is not. It is a very real problem - one not anticipated by iBiquity when they introduced the system.

 

[davideduardo]

If the secondary services are as unreliable as HD-2 is, I think those services will eventually disappear as well.

HD is one "signal" which can carry a single content stream (only the legally required stream of the underlying analog station) or add an HD-2 channel or even HD-3 and HD-4. But with each additional stream on the "signal" the bandwidth allocation has to be adjusted. An HD (1) only uses all the bandwidth. Add an HD-2 and you have to take away fromt he HD (1). And so on.

But the individual streams on the HD signal are all received in relation to the strength of that signal.

The biggest problem I am seeing is LO jamming from radios as much as 100 feet away. Traffic can stand dropouts - my garmin uses HD for traffic - the traffic information is outdated and tells me why I am stuck in traffic.

And you know this is an HD signal dropout how? You don't suppose it is the reporting service that has not yet updated the data?

But ethnic listeners will get sick of dropouts, and dropouts on data services could be catastrophic to users of those services. To make matters worse - I think I am finding dropouts due to undertones of the LO as well as the LO itself - that - or low side injection is being used on some car radios. Either way, stations across the dial are subject to LO jamming from nearby cars, whether they have HD radios or not.

First, you are assuming all use of HD (or, maybe, and equally in error) is in the car. The ethnic services heavily promote stationary (not in-car) radios and some, I am told, actually sell them at cost to potential listeners.

Kelly addressed the LO issue. As he said, in most any radio made in "modern" times the matter is irrelevant. Ditto the IF issues.

 

[Kelly A]

Glad the HD traffic is working for you on Garmin, I would have assumed DC would have even less coverage because East Coast stations are relatively limited.

The GPS in my car isn't a Garmin, but an Alpine. East Coast stations are limited? In what, coverage? Compared to where? Seems like a pretty vague statement.

LO protections are not gibberish. The existing ones are in place to give spacing between stations separated by 10.6 to 10.8 MHz. A good example is WWIA in Palm Bay on 88.5 - they got a protest from a station on 99.3 less than 20 miles away. They had to go way down on power before the FCC would sign off on the waiver of spacing rules. Now - with HD adding sidebands on adjacent frequencies, you have a whole host of new problems based on local oscillator images. If you haven't done the test I suggested - please don't call this unsubstantiated and gibberish because it is not. It is a very real problem - one not anticipated by iBiquity when they introduced the system.

The IF is 10.7Mhz. Second, you're talking about an issue that existed back in the 60's or 70's and has zero relevance to HD radio and it's reception. To claim this is a major problem now, is like saying that souvenir buggy whips made in China are a major detriment to the transportation industry today.

 

[rbrucecarter5]

The GPS in my car isn't a Garmin, but an Alpine. East Coast stations are limited? In what, coverage? Compared to where? Seems like a pretty vague statement.





The IF is 10.7Mhz. Second, you're talking about an issue that existed back in the 60's or 70's and has zero relevance to HD radio and it's reception. To claim this is a major problem now, is like saying that souvenir buggy whips made in China are a major detriment to the transportation industry today.

So ---- you didn't run the test. Why am I not surprised? Ignoring a problem or saying it doesn't exist won't fix it. If the FCC recognizes and provides protection for LO images - they recognize that the problem exists. I guess your confusion is not knowing how superheterodyne receivers work. IF may be 10.7 MHz, but to get it, each radio contains a local oscillator (LO) that operates 10.7 MHz above the received station's frequency. That LO can leak outside the radio and jam nearby radios.

East Coast stations are generally limited to 50 kW and shorter towers than full class C in the West, which can go to 100 kW and 2000 foot towers. 75 miles is about the limit on HD reception from a full class C over flat terrain. Reports I read on the board from people listening in the East give less range on HD, probably due to lower broadcast power and shorter towers.

 

[Kelly A]

So ---- you didn't run the test. Why am I not surprised?

Actually I did a test last evening when my wife drove her Audi S6 (factory radio) with HD into the garage. Parking in her usual spot about 5 feet from my car, I asked her to change her radio to WAMU HD-1 Class B 88.5Mhz. Note that we live in the stations non-city grade contour, 63 miles from the transmitter site, but never had issues receiving their HD signal. I then changed my HD radio to WAMU HD-1. As expected, there was absolutely no HD reception reduction or difference on either radio. Next I started scanning up the dial to other DC area stations which broadcast HD while my wife left her radio on 88.5Mhz. Again as expected, there was no change in her ability to receive WAMU, nor did I have any issues receiving other HD-transmitting stations all the way to 107.7Mhz. So let's review actual test results that (surprisingly yet again) disprove your claims:

1. Test location: Stafford Virginia, not in the 60db coverage area of WAMU (class B). In fact, the test was done in an enclosed garage with the door closed, attenuating even the <50db signal to far less than what it would be outside the garage. One could argue that this test was done well outside the city grade contour of all the HD stations received in this test.
2. We used two different models of modern HD-capable FM car receivers. One factory from Audi, one aftermarket from Alpine (in my car).
3. Vehicle antennas were approximately spaced ten feet apart, or 1/2 wavelength at 100Mhz. Short of touching antennas, I don't think one could come up with a better- worst case location. Final results: Absolutely no reduced HD radio reception from the Class B FM stations located outside their city grade contour with vehicle antennas located roughly 1/2 wave from each other.

So, unlike your assumption Bruce, I did a non industry standard real-world test and even bothered to document the results here. Care to divulge your particular test criteria and results which stoked your claims in this thread?

 

[davideduardo]

East Coast stations are generally limited to 50 kW and shorter towers than full class C in the West, which can go to 100 kW and 2000 foot towers. 75 miles is about the limit on HD reception from a full class C over flat terrain. Reports I read on the board from people listening in the East give less range on HD, probably due to lower broadcast power and shorter towers.

No, certain zones of the Northeast and Southwest are limited to Class B maximums, while other zones allow Class C facilities. And one zone even allows "Super" B's with 50 kw at 1000 feet and 6 kw A's at 300 meters.

It's not as simple as "East and West". There are even some states with both B and C zones. As far as the "East" the B zone ends on the NC / VA border, which is why the Norfolk / Portsmouth / Newport News market has some B's and some C's.

 

[rbrucecarter5]

Actually I did a test last evening when my wife drove her Audi S6 (factory radio) with HD into the garage. Parking in her usual spot about 5 feet from my car, I asked her to change her radio to WAMU HD-1 Class B 88.5Mhz. Note that we live in the stations non-city grade contour, 63 miles from the transmitter site, but never had issues receiving their HD signal. I then changed my HD radio to WAMU HD-1. As expected, there was absolutely no HD reception reduction or difference on either radio. Next I started scanning up the dial to other DC area stations which broadcast HD while my wife left her radio on 88.5Mhz. Again as expected, there was no change in her ability to receive WAMU, nor did I have any issues receiving other HD-transmitting stations all the way to 107.7Mhz. So let's review actual test results that (surprisingly yet again) disprove your claims:

1. Test location: Stafford Virginia, not in the 60db coverage area of WAMU (class B). In fact, the test was done in an enclosed garage with the door closed, attenuating even the <50db signal to far less than what it would be outside the garage. One could argue that this test was done well outside the city grade contour of all the HD stations received in this test.
2. We used two different models of modern HD-capable FM car receivers. One factory from Audi, one aftermarket from Alpine (in my car).
3. Vehicle antennas were approximately spaced ten feet apart, or 1/2 wavelength at 100Mhz. Short of touching antennas, I don't think one could come up with a better- worst case location. Final results: Absolutely no reduced HD radio reception from the Class B FM stations located outside their city grade contour with vehicle antennas located roughly 1/2 wave from each other.

So, unlike your assumption Bruce, I did a non industry standard real-world test and even bothered to document the results here. Care to divulge your particular test criteria and results which stoked your claims in this thread?

Love to when I get the time - but it was very similar to what you did - the only difference is the vehicles and the radio brands. I got jamming, you didn't. That is very interesting - and points to a different cause of HD dropout in my case. I love a mystery - that is how I learn things, so I am going to repeat the test with a camera running for youtube or something. I know I am not imagining the dropout. The last time I did the test, it was way before I had a problem with a bad charger. I also remember hearing 93.7 booming out of the car next to me when 104.1 HD dropped - and I caught up to the same car at three consecutive lights with HD dropping each time. I've had numerous similar experiences with different cars and different stations - all with the same result. So my observation is HD dropping in the vicinity of cars tuned 10.4 to 11.0 MHz below is a valid observation, but the conclusion it is Local Oscillator jamming seems to be flawed. I really can't think of another mechanism - but perhaps I should get an RF generator instead of relying on another radio - and see just how signal it takes to drop HD reception.

One thing is for sure, and we can probably agree - modern radio design, especially stock radios in cars - is as cheap cheap cheap as they can make it. Gone are the days of shielding, RF suppression, etc. All that matters now to automakers is squeezing a few pennies out, making sure the console shows GPS, backup camera, and that the radio gets local stations and satellite. So some local osciallator leakage is probably inevitable. Maybe it is because I am dealing with cars that have real whip antennas - back feeding of the LO out a whip antenna or something. Shark fins, nubs, windshield - most of them need a pre-amp right at the antenna to be effective. That is one more stage preventing back leakage. That could be it. I don't remember HD dropping in rental cars equipped with shark fins or nubs. So - maybe shark fins or nubs have some sort of use after all.

I think you have sold me on a different model of GPS. All Garmin does is tell me - too late - why I am hopelessy snared in traffic.

I did notice a very useful HD enhancement in the new truck my daughter's boyfriend bought. Instead of tuning up a step to get HD - you touch the HD logo to get the sub-channels. That is really intuitive - why didn't somebody do this years ago? If you know what HD is, you can use it, if not the radio works like it has for years. I didn't notice if it went into HD-1 automatically, the speaker system is kind of muffled and bassy in that truck. I don't think it did, but touching the HD logo on the touchscreen once brought it in clearer - again for HD-2, again for HD-3. Tuning off the station returned the radio to analog only until I touched the HD logo again. REALLY nice innovation!

I actually love HD because I get formats I don't get on regular analog. But that - suspected - LO dropout problem is annoying because the music goes silent for several seconds. You have put me on the path of more investigation - that's for sure. I was certain you would get the same result. But thanks for running the test!

 

[Kelly A]

I think the reason for your confusion is based on what used to be a concern when traditional Local Oscillators used in conventional receivers, verses modern SDR tuners. Most modern receivers have switched over to Phase Quadrature LO's, which cover a broad frequency range and with filtering (GSM blocker). It relies on essentially a lowpass-highpass network with amplitude stabilization being effected through feedback. I've seen graphs for these chips where image suppression caused by amplitude imbalance exceeds -60db. Much better than traditional radios where you were lucky to see -20db.

 

[rbrucecarter5]

I think the reason for your confusion is based on what used to be a concern when traditional Local Oscillators used in conventional receivers, verses modern SDR tuners. Most modern receivers have switched over to Phase Quadrature LO's, which cover a broad frequency range and with filtering (GSM blocker). It relies on essentially a lowpass-highpass network with amplitude stabilization being effected through feedback. I've seen graphs for these chips where image suppression caused by amplitude imbalance exceeds -60db. Much better than traditional radios where you were lucky to see -20db.

It doesn't have to be software defined, you are describing an architecture similar to that in the Sony CXA-1129 IC, used in the highly regarded SRF-59. Quite a departure from the traditional superheterodyne - they implement an IF that is essentially DC to 150 kHz in a nine pole low pass filter. Very slick - it is too bad the performance is wasted on a cheap tuning mechanism with bad mechanical lash. Obviously any departure from the traditional superhet architecture renders the FCC 10.6 and 10.8 MHz protections obsolete. This might open some frequencies for use in crowded metro areas. But rule changes in a politically charged FCC are slow and few.

I did a quick sanity check yesterday. Since 104.1 HD appears to be rather tenuous at best, I parked my wife's 2006 Terraza, stock GM radio beside my car - equipped with a Pioneer Supertuner 3D HD radio. Turned on the wife's radio to 93.7 - HD dropped completely. No HD-2 - no HD-1. I tried frequencies below, 93.5, HD returned. 93.3, HD worked. 93.1 - surprisingly HD worked. So what is going on here? Both radios are traditional superhet - not SDR. I was surprised 93.1 didn't cause a drop. But there is no local station on 93.1 - there is a rim shot on 93.3, and a strong local at the same antenna farm on 93.7. So perhaps it has to be a strong local to cause the jamming. I didn't have but a couple of minutes - I definitely need to document this with a video and do research on more stations - see what combinations cause the dropouts and what don't (is it 10.4 MHz and not 11.0 MHz? Why do 10.6 and 10.8 MHz seem to not matter?) A lot of unanswered questions. A moot point - because for better or worse the system is adopted, but understanding the exact nature of the problem might lead to workarounds and fixes for experienced users.

Another REALLY interesting point - 103.5 from San Marcos is a regular DX target. Before a local LPFM, it was strong enough to be on my presets. With moderate skip the last couple of mornings, I have been able to get it in HD, even to be able to decode their HD-2. That is in spite of the LPFM on the same frequency, and a strong rim shot on 103.7 that should be wrecking the upper sideband. Obviously - 103.5 has very robust HD, they are doing something better than local 104.1. Understanding what is different between the two implementations might lead to a fix - but I'd have to get inside both stations and compare equipment and firmware to see exactly what the difference is.

 

[diymedia]

Ah. It seems reports of HD's death (on FM at least) are very premature.

Death really isn't the issue. Viability and sustainability, as one of many digital platforms for radio from today onward, is. FM-HD has a hold primarily through convolutions or ancillary services—were translators not wholly reconfigured into a multimillion dollar business over the last decade-plus one huge leg of FM-HD would not be here. And that still results in an analog end-user experience. In the end, it would seem, it's not so much what you do with your spectrum as much as it is that you've got some.

 

[TheBigA]

In the end, it would seem, it's not so much what you do with your spectrum as much as it is that you've got some.

But what you do with it determines if you have the finances to continue, no?

And the FCC seems committed to using FM translators for a wide variety of services, including assisting AM and LPFM. So translators will be a life raft for many platforms. So no one has an exclusive on them.

 

[Wimmmex]

FM-HD has a hold primarily through convolutions or ancillary services—were translators not wholly reconfigured into a multimillion dollar business over the last decade-plus one huge leg of FM-HD would not be here.

Then how do you account for all the HD stations that have no translators attached to them?

In Boston, and most major markets, HD Programming is very available, and (because they won't/can't fit any more signals in the city), are not rebroadcast on translators.

I think your premise is flawed. FM-HD is here to stay, because broadcasters like the ability to have additional streams of programming (and more real estate). They are not going to give that up.

 

[TheBigA]

I think your premise is flawed. FM-HD is here to stay, because broadcasters like the ability to have additional streams of programming (and more real estate).

Technically it's the same amount of real estate.

 

[diymedia]

But what you do with it determines if you have the finances to continue, no?

And the FCC seems committed to using FM translators for a wide variety of services, including assisting AM and LPFM. So translators will be a life raft for many platforms. So no one has an exclusive on them.

Couldn't agree more! That's up to you in the industry to figure out now. But, one major plank of FM-HD's success wouldn't have happened for the wholesale warping of an analog service. Relative to what AM/LPFM get, the net benefit for HD using translators is not completely comparable.

(This is when DavidEduardo steps in to correct me.)

 

[diymedia]

Technically it's the same amount of real estate.

Only because the FCC redefined what a "channel" means during the IBOC rulemaking.

(This is when jhardis steps in to correct me.)