SPACING BETWEEN FM STATIONS

[OldChicago]

Perhaps this is not the perfect group to ask this in, but I know that there
are lost of frequency planning experts on ere.

I heard that in Mexico, they were talking about having just 400-kh'z spacing between stations in the same area. Did this ever happen? Could they try this here in the USA.

Old Chicago

 

[rbrucecarter5]

From a practical standpoint, with today's FM radio designs - even the ones with a single IF filter - 400k spacing would be fine. I've used such a radio on first adjacents about the same strength and you can still separate the stations with virtually no problem, even on a small analog tuned radio. You would get howls of complaints from station owners, though, concerned about new stations competing with them if the FCC proposed 400 k spacing in the US. So it probably won't happen. The FCC is much too busy with more important matters - taking kickbacks from iBiquity. Making sure minorities control the airwaves. Seeing to it that interference is maximized on FM as well as AM by allowing interference producing devices to proliferate freely.

 

[radiogooroo]

The FCC is much too busy with more important matters - taking kickbacks from iBiquity. Making sure minorities control the airwaves. Seeing to it that interference is maximized on FM as well as AM by allowing interference producing devices to proliferate freely.

You anti-IBOC guys are aware that you look absolutely nuts when you write stuff like this, aren't you?

 

[stan]

400 kHz spacing should be the standard. Just think of how many more broadcast choices we could have!

 

[rbrucecarter5]

The FCC is much too busy with more important matters - taking kickbacks from iBiquity. Making sure minorities control the airwaves. Seeing to it that interference is maximized on FM as well as AM by allowing interference producing devices to proliferate freely.

You anti-IBOC guys are aware that you look absolutely nuts when you write stuff like this, aren't you?

You have to admit it looks really bad. One company's system adopted with inadequate testing, a whole lot of technical problems, adds interference to the dial, has severe coverage issues. No engineer in their right mind would have adopted it as a standard. So either the FCC is totally incompetent, or taking kickbacks from iBiquity. Whatever it is - its technical problems doomed it with consumers from day one. Nobody is willing to pay a dime extra to get it in a radio, unless they are fanatical about a niche format on HD-2. And there aren't enough of those to make the product successful. This is the biggest flop since AM stereo, new coke, the PC Junior, Microsoft Bob, the Que Cat, etc. Besides iBiquity, the only ones gung-ho about it are station owners wanting to make a dime off of HD-2 ads, unload an uncomfortable format on HD-2, or they are so heavily invested in it they have too much pride to admit that the system has flopped.

 

[radiogooroo]

HD will be in 140+ models of new cars by the end of 2013.

It's not "flopped." It's just beginning.

Suggesting the Commission is taking bribes is ridiculous.

 

[landtuna]

HD will be in 140+ models of new cars by the end of 2013.

Perhaps, but as in my 2011 vehicle which came with a non-optional XM/Sirius radio, not used because of the technical problems and/or sound quality. Didn't BMW learn a costly lesson about HD radio a few years ago?

 

[rbrucecarter5]

HD will be in 140+ models of new cars by the end of 2013.

It's not "flopped." It's just beginning.

Suggesting the Commission is taking bribes is ridiculous.

Do consumers even know it is there? Do auto dealers? Last time I checked, they did not. They either think it is satellite radio or give you a blank stare. Same thing as AM stereo. Most people didn't even know it was in the car. Given a choice, they will select satellite, pandora, bluetooth, auxilary, DVD, MP3, USB, iPod interfaces over HD. It may be in 140 models of car as a option - that doesn't mean its actually available in dealerships, nor does it mean the dealer has ordered vehicles with it installed for their inventory. They go with more popular options.

 

[rbrucecarter5]

HD will be in 140+ models of new cars by the end of 2013.

It's not "flopped." It's just beginning.

Suggesting the Commission is taking bribes is ridiculous.

And YES, I'll accuse the FCC of taking bribes. Any time - to their face. Bribes don't have to be money, they can be suggestions of political favor if you support one digital system over another. There were competing systems, that were technically much better. Why did we end up with iBiquity? Because Clear Channel is big and powerful. If they didn't bribe their defective system into law, they sure applied high pressure to the right people in high places to get it enacted. Something is really wrong when a critically flawed system like iBiquity ends up being adopted. I'd love to find out exactly how it happened, and blow the whistle on it - because it is the American public who is now stuck with a defective system that has poor robustness, and splatters all over adjacent frequencies. On the AM side, it doesn't work at night unless you are on top of the tower. And it splatters on not just first adjacents, but second adjacents as well. There were some real programming options on some of those second adjacents - so I even suspect some broadcasters are intentionally jamming competitors with HD. There have been some complaints by broadcasters to that effect. Corruption, incompetence, and money often go together. I wish I had proof, but I don't.

We needed a robust, low cost, low power system that had the potential to really revolutionize the dial. It should have been enacted on a new band, with existing broadcasters given spectrum there. With careful selection of the system and the new frequency band, we could right now have fully digital three band receivers in cars, with extremely good coverage, interfering with nobody, allocations done intelligently instead of the current state of both AM and FM bands. Consumers would more readily adopt it because it would actually WORK when they tried it out intead of drop out and not lock like iBiquity. The best case scenario - the FCC didn't know what the heck they were signing off on - they trusted iBiquity, who did bad engineering and inadequate testing on the system. When and if they discovered problems - instead of going back to the lab and re-designing until the problems were solved, they covered them up, glossed them over, misrepresented facts to fit their cherished assumptions - the essence of bad science and bad engineering. A little example is when they said the GE Superadio 3 is not a broadband receiver, then published an IF bandwidth spec for wideband that clearly matched the narrow setting of the bandwidth switch. They further said that all radios are narrowband, when the old tired "3 IF can" reference design had not been manufactured in 20 years. All new AM sections now consist of an IC and one really sloppy wideband ceramic filter. Little misrepresentation of facts like that all through their published material completely erases their credibility with serious engineers such as myself. And cries out of cover up after cover up of engineering blunders and deficiencies, sloppy test techniques, tests designed specifically to make their system look good. Take your choice: bad engineering, cover ups, money, influence peddling. The big losers - the American public, iBiquity's investors who are going to take a financial hit, and ultimately broadcasters who did not get the digital upgrade they deserved.

 

[radiogooroo]

Perhaps, but as in my 2011 vehicle which came with a non-optional XM/Sirius radio, not used because of the technical problems and/or sound quality. Didn't BMW learn a costly lesson about HD radio a few years ago?

I have no idea what BMW learned or didn't learn about HD radio. I don't obsess over this stuff.

When people come totally unhinged like rbrucecarter is right now, accusing the FCC of taking bribes, etc. it just makes the anti-IBOC guys look nuts. If any of you had any valid points, they're totally lost in the insanity.

It doesn't matter anyway. Good, bad or indifferent, the system is in place. It's not going away. According to the little update I got in my email inbox a few days ago, it's going to be in 140+ models of new cars by the end of 2013. It's in place on virtually every FM in every major market. The capital expenditure has been made, and it's here to stay whether anyone likes it or not.

 

[Kent]

Do consumers even know it is there? Do auto dealers? Last time I checked, they did not. They either think it is satellite radio or give you a blank stare. Same thing as AM stereo. Most people didn't even know it was in the car. Given a choice, they will select satellite, pandora, bluetooth, auxilary, DVD, MP3, USB, iPod interfaces over HD. It may be in 140 models of car as a option - that doesn't mean its actually available in dealerships, nor does it mean the dealer has ordered vehicles with it installed for their inventory. They go with more popular options.

The press release clearly states these will be OEM radios. That implies, to me anyway, that you get HD Radio if you buy one of those cars. It also clearly states HD Radio is "standard equipment."

Assuming it really is standard equipment, you don't have to know if HD Radio is in your car. I can't imagine there will be any choosing HD. They'll simply choose AM or FM, and they'll get HD if they can receive it on the station they want to hear. So, it won't likely be a matter of selecting these other forms of entertainment over HD. It will be whether they want radio or something else.

 

[landtuna]

I have no idea what BMW learned or didn't learn about HD radio. I don't obsess over this stuff.

To quote a popular expression "it wasn't ready for prime time". BMW offered HD in their cars but suffered major warranty losses when buyers kept bringing their cars back because "the radio doesn't work". Intrinsic technical failures (insufficient range and loss of lock primarily) meant that, while the HD sound quality was good the signal wasn't reliable and unfortunately the problem is in the technology and not the individual radio units.

All this has been covered in great detail in earlier posts in this forum.

When people come totally unhinged like rbrucecarter is right now, accusing the FCC of taking bribes, etc. it just makes the anti-IBOC guys look nuts. If any of you had any valid points, they're totally lost in the insanity.

I can't defend 'rbrucecarter' but I can suggest you read historical posts if you need oodles of issues regarding HD radio.

It doesn't matter anyway. Good, bad or indifferent, the system is in place. It's not going away. According to the little update I got in my email inbox a few days ago, it's going to be in 140+ models of new cars by the end of 2013. It's in place on virtually every FM in every major market. The capital expenditure has been made, and it's here to stay whether anyone likes it or not.

The main issues with HD obviously concern the broadcast industry itself because, quite frankly, the man on the street doesn't give it a second thought and that is assuming he knows what it is in the first place. Sooner or later those capital expenditures are going to need upgrading, licensing or replacement and then we'll see just how popular HD radio is.

And one last problem area for HD radio that has nothing to do with the technology itself. You have almost two generations of listeners who have become accustomed to compressed audio through tinny earbuds. The very slight audio quality advantage of HD is going to be indecipherable to them and they will care even less than the very small number of listeners do today. And that is assuming there is HD content that attracts them in the first place. I doubt rap sounds any better on HD.

 

[radiogooroo]

I have no idea what BMW learned or didn't learn about HD radio. I don't obsess over this stuff.

To quote a popular expression "it wasn't ready for prime time". BMW offered HD in their cars but suffered major warranty losses when buyers kept bringing their cars back because "the radio doesn't work". Intrinsic technical failures (insufficient range and loss of lock primarily) meant that, while the HD sound quality was good the signal wasn't reliable and unfortunately the problem is in the technology and not the individual radio units.

All this has been covered in great detail in earlier posts in this forum.

When people come totally unhinged like rbrucecarter is right now, accusing the FCC of taking bribes, etc. it just makes the anti-IBOC guys look nuts. If any of you had any valid points, they're totally lost in the insanity.

I can't defend 'rbrucecarter' but I can suggest you read historical posts if you need oodles of issues regarding HD radio.

It doesn't matter anyway. Good, bad or indifferent, the system is in place. It's not going away. According to the little update I got in my email inbox a few days ago, it's going to be in 140+ models of new cars by the end of 2013. It's in place on virtually every FM in every major market. The capital expenditure has been made, and it's here to stay whether anyone likes it or not.

The main issues with HD obviously concern the broadcast industry itself because, quite frankly, the man on the street doesn't give it a second thought and that is assuming he knows what it is in the first place. Sooner or later those capital expenditures are going to need upgrading, licensing or replacement and then we'll see just how popular HD radio is.

And one last problem area for HD radio that has nothing to do with the technology itself. You have almost two generations of listeners who have become accustomed to compressed audio through tinny earbuds. The very slight audio quality advantage of HD is going to be indecipherable to them and they will care even less than the very small number of listeners do today. And that is assuming there is HD content that attracts them in the first place. I doubt rap sounds any better on HD.

Yeah, you guys have been preaching this stuff for years, but it's still here.

Given the fact that HD is now being monetized in big ways through translators, and in lesser ways through various data feeds like traffic info to HD enabled GPS devices by every one of the major broadcast companies, I suspect they'll pony up for repairs, etc. I don't see any of them doing anything to undermine these new revenue streams.

But preach on brother, preach on. Don't forget to complete the look with a tin foil hat. Lol...

 

[davideduardo]

To quote a popular expression "it wasn't ready for prime time". BMW offered HD in their cars but suffered major warranty losses when buyers kept bringing their cars back because "the radio doesn't work".

No, that is not true. An ambulance-chasing law firm either looked into or actually sued BMW in a class action. This action was based on a couple of reports and a lot of garbage from some HD-hating folks.

I asked the service managers at the two BMW dealers I go to, one of them a top-10 dealer nationally. Both said that they had never had such complaints.

I have or have had 4 BMWs with HD in them, and the radios work fine, and the HD works very well, particularly on AM in noisy metro areas.

Intrinsic technical failures (insufficient range and loss of lock primarily) meant that, while the HD sound quality was good the signal wasn't reliable and unfortunately the problem is in the technology and not the individual radio units.

Again, using my car HD radios as examples, in areas outside metro LA, such as Redlands, San Bernardino or Oceanside, where the KFI and KNX analog signals are beginning to be noisy, the HD signal is fully locked and clear and interference free. On FM, I've carried Phoenix FMs like KNIX and KMLE almost to Quartsite on HD.

Whether there is an economic reason to have HD is different... and I believe that for AM it's a non-productive effort.

AM is fading, and irrelevant to most Americans. And in the top 100 metro areas, the average is less than 2 viable AM facilities per market, so most stations can't benefit from HD because they are horrible facilities anyway.

On FM, the real benefit other than FM translators is in the HD2 and HD3 channels. While commercial FMs have been stopped from making any significant contribution on Hd due to the recession, the NPR stations are examples of providing valuable new services on HD channels.

 

[davideduardo]

Making sure minorities control the airwaves.

Wow. Please elaborate.

 

[stan]

I'm curious about HD, and it's robustness. Would it work with 400 khz spacing? 200 KHz spacing?

 

[landtuna]

To quote a popular expression "it wasn't ready for prime time". BMW offered HD in their cars but suffered major warranty losses when buyers kept bringing their cars back because "the radio doesn't work".

No, that is not true.

It was a serious enough problem that required BMW to issue several service bulletins - the first in March of 2007 with a follow-up in August.

 

[davideduardo]

It was a serious enough problem that required BMW to issue several service bulletins - the first in March of 2007 with a follow-up in August.

BMW can issue several service bulletins a day. Everything that might help another dealer reduce warranty repair cost, which BMW pays, is documented for reference.

The fact that a couple of morons could not tune their radio does not indicate a real problem.

There are literally thousands of bulletins about the iDrive, but BMW's still have iDrives.

 

[rbrucecarter5]

I'm curious about HD, and it's robustness. Would it work with 400 khz spacing? 200 KHz spacing?

Robustness on HD FM - I have done a careful survey 70 miles from the Dallas towers with a dipole held at one meter off of the ground. All Dallas HD FMs locked. I'd call that robust enough for just about any purpose, especially since my listening site was a rural area surrounded by ranches and livestock. Not much audience potential when houses are spaced a mile or more apart. Another observer has done tests 84 miles from the Houston towers and reported reliable HD lock with a dipole at ceiling level.

HD would work with 400 kHz spacing, but barely. If both stations were running HD, theoretically the sidebands would clear each other. In reality, though, you would need close to a brick wall IF filter. The only FM tuner ever manufactured with an IF sharp enough is the Marantz 10-B, but I don't know if it could be retrofitted with an HD decoder.

HD would not work with 200 kHz spacing. Before HD, the deviation from carrier was +/- 75 kHz, meaning FM stations fit neatly within the 200 kHz channels. Because most of the deviation was considerably less than +/-75 kHz, first adjacent reception on equal powered stations was relatively easy, even on inexpensive receivers. HD, however, increases the deviation to the point that it overlays first adjacent channels. Two HD stations, spaced at 200 kHz, with equal signal strength would interfere destructively with each other. HD is especially sensitive to interference, so neither station could be received in HD. There have been tests with asymmetrical sidebands that might give the scenario a chance if both stations used the sideband away from the other, but I doubt such a test has been run. iBiquity obviously did not test their system adequately prior to its introduction.

Going back to the Dallas scenario, there is one important exception to the HD robustness scenario. Listeners in the DFW area who are less than ten miles from the towers, but on the approach path to DFW airport, report that HD lock is unreliable. The planes cause fades in the 60 dB range, causing HD to drop out of lock. Given that the airplane flutter is fractions of a second and the lock time is several seconds, HD reception near airports or along approach paths is not practical. Proposals to increase sideband power by a paltry 6 to 10 dB will do nothing to combat 60 dB signal fluctuations.

 

[rbrucecarter5]

When people come totally unhinged like rbrucecarter is right now, accusing the FCC of taking bribes, etc. it just makes the anti-IBOC guys look nuts. If any of you had any valid points, they're totally lost in the insanity.

Thank you for allowing me to win the debate. How you ask? Debate 101 - if you attack or insult your opponent, they win by default. So - I win! You lose. I guess HD radio is indefensible for you to resort to such desperate tactics.

By the way, because I am a Christian believer, any insult or curse you hurl my way automatically returns on you. I am protected by the blood of Christ from such things. So think twice before you mess with one of Christ's followers. You cannot win.