HD Radio’s History of Innovation and Future of Growth

[Kevin]

The smaller the city or market, and the less band clutter, the better, with translators. In large markets, the frequencies may be duplicated two or more times in the same market. Those translators are just about useless, unless there is a concentration of unique demographics within a few miles of the translators.

Really, the FM band is getting much more cluttered than AM ever was with all the translators and IBOC sidebands. Really, there should have been separate bands for digital and translators. A small number of MHz, even two, could accommodate 1000 or more translators at 1 kW/100 meters. I figured it out. I came up with a set of rules. I'm sure no one at the FCC would listen.

I totally agree with you. In Detroit we have some frequencies that have triplicate translators on them not only the translators but we have at least a half a dozen Windsor stations as well. 96.7 has an LPFM a translator and a Windsor full power, 105.5 has a Windsor station 2 translators in the Detroit metro area and 107.1 has 2 translators a full power station in Ann Arbor and a full power in Port Huron. That’s just a few examples and there will be more translators in the next couple of months. It’s turning into an over crowded broadcast band for sure.

 

[TheBigA]

Manufacturers don't want to offer products that only work in one country.

Although it was a whole lot easier when electronics were made in the USA and several of the biggest manufacturers also owned radio stations.

 

[davideduardo]

I totally agree with you. In Detroit we have some frequencies that have triplicate translators on them not only the translators but we have at least a half a dozen Windsor stations as well. 96.7 has an LPFM a translator and a Windsor full power, 105.5 has a Windsor station 2 translators in the Detroit metro area and 107.1 has 2 translators a full power station in Ann Arbor and a full power in Port Huron. That’s just a few examples and there will be more translators in the next couple of months. It’s turning into an over crowded broadcast band for sure.

Saying that having stations in Windsor crowding the dial is like saying that having stations in Minneapolis crowd the St. Paul dial... or Dallas and Ft. Worth or Austin and San Antonio and so on. All population centers get as many stations as will fit on the dial within the technical standards.

San Diego and Tijuana, both huge cities divided by a jurisdictional line, share the band so that some available channels are in one and some in another.

In the cases of translators, they are put on channels where no station has the minimum protected contour.

 

[davideduardo]

Although it was a whole lot easier when electronics were made in the USA and several of the biggest manufacturers also owned radio stations.

Yet look at how RCA kept FM from prospering for over two decades just to prevent it from interfering with the development of TV and then out of spite against Maj. Armstrong!

At one point, they even got the FCC to move the whole band to make things harder!

 

[Schroedingers Cat]

Well, in the Windsor Area, you have stations or boosters on many second adjacent frequencies to Detroit Area stations. In the US, stations in the largest cities occupy every fourth channel, and second adjacent channel stations are generally 40 plus miles away. However, those same second adjacent frequencies are now occupied by translators the US, which are cochannel to the Canadian stations just across the border. You can talk about contour protection all you like, but in reality there are many interference areas.

As far as the old FM band, it only went from 42-50 MHz, or only 40 channels, and those frequencies are frequently affected by Sporadic E interference compared to 88-108 MHz. The AM BC Band has always had close to 100 channels, at least going back to 1930, 96-117 since then.

 

[KeithE4]

At one point, they even got the FCC to move the whole band to make things harder!

Which was the smartest decision they could make at the time. 8 MHz just wasn't enough for FM broadacst. As we're seeing now, 20 MHz isn't enough but there's nowhere else for FM to go. It's "landlocked" on both sides of its spectrum.

Not only that, but 42-50 MHz is much more susceptible to skip than 88-108 MHz (which is bad enough). They should have gone even higher, above 150 MHz, but other services' needs plus mid 1940s technology just wouldn't allow for it.

 

[davideduardo]

Which was the smartest decision they could make at the time. 8 MHz just wasn't enough for FM broadacst. As we're seeing now, 20 MHz isn't enough but there's nowhere else for FM to go. It's "landlocked" on both sides of its spectrum.

Not only that, but 42-50 MHz is much more susceptible to skip than 88-108 MHz (which is bad enough). They should have gone even higher, above 150 MHz, but other services' needs plus mid 1940s technology just wouldn't allow for it.

All those were logical reasons to move FM. But the reason RCA pushed for it was to slow down any possible development of the "new" band as their interests were in television and Sarnoff believed that any reason to divert consumer money to another product was a threat.

 

[KeithE4]

All those were logical reasons to move FM. But the reason RCA pushed for it was to slow down any possible development of the "new" band as their interests were in television and Sarnoff believed that any reason to divert consumer money to another product was a threat.

Yep. Pushing for the right solution but for the wrong reasons.

 

[Ralph Martin]

So in case any of you think I'm an anti-analog/HD Radio advocate, I thought you'd get a kick out of this:

My recent infamous final exam for my beginning middle school radio operations class was one question:

1. What is the correct answer to this question? _________

The answer was random, so I needed to tell them what to write on the test.

I encoded the answer to the test into the electrical wiring of the building by injecting an amplitude modulated carrier. I then gave each student these items:

-- some copper wire
-- a roll of toilet paper
-- a safety pin
-- a razor blade
-- a broken pencil
-- some thumbtacks

The students' task was to design and build a device using only those items to decode the message and hear the answer the question.

Here is an example of a student's working solution:

Some of you probably recognize this as a carrier current AM injection and a Crystal (foxhole) radio circuit.

Radio, at its basic level, is both simple and fascinating. Can't do stuff like this with HD Radio.

Happy New Year everyone!

 

[Schroedingers Cat]

Did people actually get those Foxhole radios to work? I tried with a Cat's Whisker, I tried with a 1N34, still never heard anything but the weakest audio, with a similar setup, even with several signals in the 50-100 mV/m range, and 50 or more feet of antenna wire. My Hearever Rocket Radio worked great, several stations heard with the clip hooked up to a pole lamp switch, one down to 25 mV/m at Night. With 125 feet of wire, you could hear WCFL and WOWO though, intermittently, quickly in and out.

 

[Ralph Martin]

Did people actually get those Foxhole radios to work?

In the video, you're hearing the audio coming from the crystal radio. These radios are extremely basic , not very sensitive and not very selective . You either need a piezoelectric earphone or you can hook it up to an amp to hear the audio without one. There are still crystal radio enthusiasts who create some very interesting and elaborate takes on the foxhole radio. The Crystal Radio Club site has some unique sets. With a good outside antenna - decent ground, especially with a strong local station, they can work fairly well. In our case, I was transmitting in the room's electrical wiring so the signal was plenty strong enough to power their radios if they built them correctly. They all did.

The razor/pencil detector requires that the razor be heated (blued). I had a torch handy

 

[Kevin]

It's another option.

It’s another opinion on another device. People do love more options, but on one device their smartphone and that’s where everything is headed. Everything will eventually be done on our smartphones. During this Covid nightmare people are more dependent on their smartphone, from banking, business meetings to entertainment all done over the phone or computer. The bottom line is, more options not more devices but more options one device.

 

[Kevin]

I meant to say option not opinion, my bad, love that spellcheck feature.

 

[TheBigA]

The bottom line is, more options not more devices but more options one device.

What that does is it puts the phone companies in control of what options you'll get on those devices.

 

[Kevin]

I find it interesting that Bose has yet to manufacture a Bose HD Radio. Of course it probably would retail for about $800.00 for one. That could change in 2023 after that patent runs out.

 

[Don CT]

I find it interesting that Bose has yet to manufacture a Bose HD Radio. Of course it probably would retail for about $800.00 for one. That could change in 2023 after that patent runs out.

If you want mass adoption you need alarm clocks with HD Radio.

 

[Kevin]

Another interesting fact is Bose does have an internet receiver. I believe it’s The Bose Wave Sound Touch IV. And yes great point Don, HD Radio alarm clocks.

 

[TheBigA]

Another interesting fact is Bose does have an internet receiver

HD Radio is a trademarked and copyrighted technology, owned by DTS and Xperi. The internet is freeware.

Anyone can make internet radios, just as anyone can make AM/FM radios.

 

[Kevin]

HD Radio is a trademarked and copyrighted technology, owned by DTS and Xperi. The internet is freeware.

Anyone can make internet radios, just as anyone can make AM/FM radios.

I get that, as you have said the patent runs out in 2023 but Bose could have had HD Radio Receivers but choose not too. Instead they do have internet receivers.

 

[TheBigA]

Bose could have had HD Radio Receivers but choose not too. Instead they do have internet receivers.

HD stations are usually streamed on the internet, so it serves the same purpose.

Bose also makes a smart speaker and HD stations can be heard on smart speakers.