AM HD TURNOFF PACE ACCELERATES

[Kelly A]

The reason why AM is left off is because engineers designing radios don't know how to do their jobs, and the digital stuff in the radios causes interference to AM,

All newer radios (10 years or less) are Software Defined Radios (SDR). There are no new designs being made and no engineers designing them for the Medium Wave (AM) broadcast band. Now engineers at Delphi and alike, are working on in-car connectivity and user experience functions. Higher-end vehicle entertainment systems are rapidly becoming devoid of AM tuners anyway. Like it or not, that is the trend.

and they don't know how to isolate ground places and decouple. Analog design is a vanishing art, and the engineers don't know it.

Maybe the "engineers" you speak about don't know it, because they aren't being assigned to work on a solution that's run it's course? Analog-anything is vanishing, period.

i-Anything is not going to work well on AM or FM.

As David correctly points out, that's because most people who rely on their IPhone, or other 'smartphone' for information and entertainment, can care less about AM or FM radio. They get what they need on a single device that fits in their pocket or purse.

 

[landtuna]

Analog-anything is vanishing, period.

Except in automobile speedometers. For some reason even the luxo-rides come with analog speedos now. I know I prefer analog.

 

[davideduardo]

As David correctly points out, that's because most people who rely on their IPhone, or other 'smartphone' for information and entertainment, can care less about AM or FM radio. They get what they need on a single device that fits in their pocket or purse.

And the great advantage is that all the stored content travels with the smart device and is accessible in the car, at home, at work or in the park or wherever. You learn the "controls" for a singe device and have apps for each function you want, from traffic and weather to music and video. For members of the Internet generation (and many of the rest of us, too) it is easier to find our "radio" sources on the smartphone than on separate radios that all seem to have strange and counter-intuitive controls and buttons.

 

[landtuna]

My smartphone has a working FM chip and it works great except it requires earphones to be plugged in as that is the antenna (FM only). You can play the audio through the smartphone speakers but you still need to have earphones plugged in. Weird design.

I have a pair of old earphones that only works with one earpiece so I'm thinking of cutting off both earpieces and using that for the FM antenna. As soon as I can find the damn earphones I will give it a try.

 

[davideduardo]

Weird design.

Not weird at all. An antenna works most efficiently at the wavelength of the transmitted signal. Anything less than a full wavelength will be progressively less efficient. For FM, a good antenna is somewhere in the size range of the old 30 inch wire whips.

Antennas in glass windshields approach those lengths, but are directional to some extent. And the shark fins have less efficiency and depend on amplification and sometimes folded elements. A cellphone is too small for a good FM antenna, and a near impossibility for a good AM one. So they use exterior antennas such as the headphone leads. This is similar to the table, clock and kitchen FM radios that use the power cord for an antenna.

 

[Kelly A]

Except in automobile speedometers. For some reason even the luxo-rides come with analog speedos now. I know I prefer analog.

Even in the case of that analog-appearing speedometer or gauges, they are all technically digital. The entire dashboard of modern cars is fed by a single network (data) and cable that is part of your vehicles nervous system called the CANBUS. The brain which tells the gauges what to display is called the BCM, or Body Control Module.

 

[landtuna]

Even in the case of that analog-appearing speedometer or gauges, they are all technically digital. The entire dashboard of modern cars is fed by a single network (data) and cable that is part of your vehicles nervous system called the CANBUS. The brain which tells the gauges what to display is called the BCM, or Body Control Module.

Right. I was talking about the display.

 

[rbrucecarter5]

Even in the case of that analog-appearing speedometer or gauges, they are all technically digital. The entire dashboard of modern cars is fed by a single network (data) and cable that is part of your vehicles nervous system called the CANBUS. The brain which tells the gauges what to display is called the BCM, or Body Control Module.

Somewhere in the system, though, is an analog to digital converter, usually a functional block inside a microcontroller. It interfaces to sensors that are analog. If something analog is being controlled by a microcontroller, it is coming from some form of digital to analog conversion - whether it is an automatic braking system engaging a solenoid, or phase switching in a class G amplifier. The real world is analog. The only digital thing in the real world is DNA.

Ugh - I hate CAN bus! It has a failure mode where one transceiver can be stuck in the "transmit" mode jamming the rest of the nodes. My daughter's first car had that. It caused the emission control system to dump five gallons of gas into the engine at once, causing it to stall, putting . Replacing the transceiver chip didn't help - it was the firmware in the car. Several calls to Detroit later, their firmware engineer acknowledged the problem, but they refused to do a safety recall. We sold the car at a loss and got something else.

 

[rbrucecarter5]

All newer radios (10 years or less) are Software Defined Radios (SDR). There are no new designs being made and no engineers designing them for the Medium Wave (AM) broadcast band. Now engineers at Delphi and alike, are working on in-car connectivity and user experience functions. Higher-end vehicle entertainment systems are rapidly becoming devoid of AM tuners anyway. Like it or not, that is the trend.

As David correctly points out, that's because most people who rely on their IPhone, or other 'smartphone' for information and entertainment, can care less about AM or FM radio. They get what they need on a single device that fits in their pocket or purse.

Clock rates on DSP microcontrollers are not fast enough to implement SDR on FM, and probably won't be for a long time, if ever. SDR AM is in my Pioneer aftermarket radio, and is quite good. Almost as sensitive as a Delco from the 60's with a long whip. I suspect they did that in an attempt to make HD-AM work. The drawback with SDR AM is it is prone to overload because the core of the microcontroller is operating at something between 1.5 to 3.3V, not a lot of room for voltage swing when the station varies greatly in amplitude. On the plus side - it saves your ears when driving under power lines.

David, I think, overestimates the willingness of people to spend money on data plan overages just to stream radio on their phones. I am grandfathered in at unlimited, but most people have to pay and pay. It makes satellite downright cheap by comparison.

 

[Kelly A]

Clock rates on DSP microcontrollers are not fast enough to implement SDR on FM, and probably won't be for a long time, if ever.

You mean like this one from NXP that's been put in radios since 2005? http://www.nxp.com/products/media-a...utions/dsp-based-radio-tuner-one-chip:TEF665X

 

[rbrucecarter5]

You mean like this one from NXP that's been put in radios since 2005? http://www.nxp.com/products/media-a...utions/dsp-based-radio-tuner-one-chip:TEF665X

Read the data sheet carefully. Nowhere does it state that the front end is digital (Data sheet figure 1 - good old fashioned analog front end! There is an ADC after the front end. And since DSP's are not fast enough yet to reach the Nyquist point of a 10.7 MHz IF filter, and sure weren't back in 2005 - they are doing the same thing as Sony in the CXA1129 - using a lower FM IF frequency. They would have to. And - look at the output. Good old fashioned stereo DAC, just like I said.

Nice chip, though. I'll order a couple to experiment with and see if I can deduce the FM IF frequency. I bet it has great selectivity!

 

[rbrucecarter5]

And the patient is AM radio. AM HD is just a treatment that was applied to late and didn't work.

I would submit that even C-Quam was too late. It didn't matter that it worked. Music had moved to FM, the window of opportunity lost.

 

[JohnnyElectron]

Sorry to dig-up this thread, but Sangean has 3 new HD radios- BUT, my guess is that it was subsidized by iBiquity as their top of the line stereo tuner DELETES all the wonderful features that they added to their HDT-1X tuner, like the HD time lag mode, CQUAM AM stereo, forced analog. I contacted their contract engineer and he confirmed that they 'de-contented' these items, even though it cost next to nothing to program the features- sad, could have made a nicer, newer tuner for analog AM at least, but all they want to do is showcase the HD and screw the analog section. Sad

 

[davideduardo]

Sorry to dig-up this thread, but Sangean has 3 new HD radios- BUT, my guess is that it was subsidized by iBiquity as their top of the line stereo tuner DELETES all the wonderful features that they added to their HDT-1X tuner, like the HD time lag mode, CQUAM AM stereo, forced analog. I contacted their contract engineer and he confirmed that they 'de-contented' these items, even though it cost next to nothing to program the features- sad, could have made a nicer, newer tuner for analog AM at least, but all they want to do is showcase the HD and screw the analog section. Sad

iBiquity is not going to subsidize any receivers since its only significant source of revenue is the sale and licensing of HD chipsets for receivers.

Unlike Sirius / XM which makes its money off subscriptions and can afford to incentivize car manufacturers and dealers, iBiquity makes no money off the back end and thus can not pay to have chips put in radios.

 

[davideduardo]

I would submit that even C-Quam was too late. It didn't matter that it worked. Music had moved to FM, the window of opportunity lost.

And that all was due to a legal battle initiated by the inventor of one of the five competing AM stereo systems. It held up adoption of a standard (which turned out to be no standard at all) for about 5 years. So instead of getting AM stereo in 1977-78, we got it in 1982.

In 1977, more than half of all listening was still on AM. There was a platform for AM stereo to launch from. By 1982, as you say, the window had closed; not only had most music listening moved to FM but many of the AMs that played music in '77 had already moved to talk or other more niche formats by the early 80's.

 

[Kelly A]

First, Kudos to Bruce for his correct comment regarding AM stereo. Second, David is being respectful, but I'll go out on a limb and say it: Leonard Kahn and his litigious ways, was a major factor as to why AM stereo failed.

 

[davideduardo]

First, Kudos to Bruce for his correct comment regarding AM stereo. Second, David is being respectful, but I'll go out on a limb and say it: Leonard Kahn and his litigious ways, was a major factor as to why AM stereo failed.

In my opinion, he was the sole assassin of all AM radio.

 

[mimo]

I'm not even sure AM stereo helped the situation in Canada, where music on AM survived well into the 1990's. Most of that had to do with format and music regulations, AM was for the hits, FM for the album cuts. We did see a lot of promotion of AM stereo up here, and receivers were actually findable in stores. I saw my first AM stereo radio back in 1983 in Calgary when we didn't even have an AM stereo station locally, but we were able to easily hear 630 CHED from Edmonton who went stereo back in July of that year. Calgary wouldn't get an AM stereo station until January of 1984 when 2 stations added it and a 3rd AM went on the air that year, broadcasting in Stereo from the beginning. We also chose a standard several years before the U.S. did. Now we're licensing HD on FM stations, and using the HD 2's and 3's for simulcast of AM stations. The CRTC has said that there are no plans to license it on AM.

 

[MarioMania]

Leonard Kahn didn't get his way, So he threw a hissy fit when his Standard didn't get approved for AM Stereo

 

[Kelly A]

In my opinion, he was the sole assassin of all AM radio.

I'd say fifty percent was also related to the Commission lack of choosing a standard and sticking to it, as they did in the 60's with choosing the method of modulating FM stereo.

The FCC announces their selection of Magnavox as being the approved standard for AM stereo, then totally sold out when several broadcasters complained. After choosing a standard, then announcing they would let the marketplace decide was completely a chicken-sh*t move. Leonard's ongoing lawsuits were the nail in the AM stereo coffin.

Fortunately the Commission learned from that experience when it came to a broadcast band digital standard. Like it or not, for right or wrong, in choosing Ibquity as the digital IBOC standard for the US, at least the FCC made a decision and stuck with it.