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Congress wants to force AM into every new car for emergency alerts.
The fight over the future of AM radio got a little more heated this week as organizations representing the auto and technology industries told Congress that its plan to mandate this mode of radio wave reception is poorly conceived and will hinder progress.
AM radio has seen almost every other in-car entertainment option come and go—vinyl, 8-tracks, cassettes, CDs—and it might predate just about everything other than playing "I Spy," but time is catching up with this old broadcast technology. It is starting to get left behind as new models—many of which are electric vehicles—drive off into the sunset, streaming their audio instead of modulating its amplitude.
[...] "As more and more Americans adopt electric vehicles, we must ensure that they are equipped with AM radio. AM radio is—and will remain—an essential communications channel for emergency alerts and for disseminating news and other important information to residents of our district and communities across our country. I am proud to co-lead this bipartisan legislation which would ensure that EVs continue to be equipped with this basic but critical capability," said Rep. Bob Menendez (D-N.J.), another co-sponsor.
(Score: 4, Insightful) by owl on Wednesday May 24 2023, @03:10PM (12 children)
All of which is already occurring today in any car where the driver has tuned to an AM station. At least in markets with a higher level of Tesla (and the like) purchases than most. Around me I see Tesla's all the time. So anyone tuning AM is already hearing static caused by Tesla's.
And, of course, this is nothing new. I remember late 1970's cars, with only AM radios, and the reception was already full of static and pops and glitches anyway (and, if you knew what you were listening for, you could estimate engine RPM by the tone of the alternator whine). AM and static have been a pairing for as long as AM has existed.
Why the sudden desire on the part of car makers to drop AM (other than possibly to "ape teslla") none of us know -- but static and interference on AM stations has been a constant forever, so 'static' alone is not likely the real reason why.
(Score: 2) by JoeMerchant on Wednesday May 24 2023, @03:28PM (11 children)
I think the situation is: while AM static of the 1970s was annoying, AM static of the 2030s is likely to render the band unusable, unintelligible, absolutely worthless.
Being able to drop "AM compatibility" from their list of design criteria will enable future automakers to make even more profit on the cars they will be selling. You can't claim AM compatibility when your own vehicle is rendering the radio output useless any time the vehicle is moving.
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(Score: 3, Interesting) by RS3 on Wednesday May 24 2023, @03:31PM (10 children)
AFAIK FCC required spark-ignition engines to use resistor plugs and plug wires to reduce EMI. Is this whole thing about EVs not complying with RF emissions, and EV makers and industry groups fighting RF shielding and general RF noise reduction?
(Score: 2) by owl on Wednesday May 24 2023, @03:45PM (1 child)
That's what it sounds like. They don't want to adequately shield/filter their noise, and the FCC's not on the ball to force the issue.
(Score: 2) by RS3 on Wednesday May 24 2023, @04:16PM
So who's in charge of FCC? Who should be holding their feet to the fire?
If my hunch is right, that EV makers (and others) don't want to bother with fixing RFI problems, it's obviously not just AM radio that suffers. CB radio, HAM, and probably many others I haven't thought of yet.
My fear is: if this problem isn't clamped down on soon, by the time various people groups collaborate and demand action, it will be too late- too many electrically noisy cars out there, too expensive to fix.
This feels far too much like the whole FAA / Boeing / MCAS / many deaths problem. Govt. agencies not doing their jobs but still raking in pay and great benefits including long-term pensions.
(Score: 2) by JoeMerchant on Wednesday May 24 2023, @04:15PM (7 children)
I believe that's it, and I believe this go-around they have some legitimate concerns about the costs involved to shield a "modern, efficient" EV powertrain from causing AM interference.
Anything is possible, I'm sure they can make an EV that's absolutely radio-silent on the whole AM band, but that would eat into profits because nobody is actually going to pay extra just because they can listen to AM radio.
🌻🌻 [google.com]
(Score: 3, Interesting) by RS3 on Wednesday May 24 2023, @04:32PM (3 children)
"FCC": Feckless Communications Commission. Our tax dollars at work.
It's not just shielding- there are many electronic techniques to reduce RFI, including snubbers. It requires an impetus toward RFI reduction from the start of the design process.
(I'm sure you and others know this- I'm just writing, as often, for those who might not know). In industry / factories, and more and more places, we're using 3-phase motor controllers. Most new clothes washing machines use them, water well pumps, EV motors, on and on. As many of you know, the controllers employ semiconductor switching, which is great, but that fast current switch dI/dt makes big RF noise.
One great way to reduce the noise: by interesting properties of electromagnetism, you can twist wires and they'll mutually shield themselves- against emitting RFI, and they'll also be better at rejecting incoming electrical noise. Ethernet wire is a great example of this- balanced signal pair (one is an inverted signal of the other's signal), and this works with 3-phase. I've installed motor controller (sometimes called "drives", VFD, etc.) to motor wires that were 3 conductor, twisted and shielded. The main reason in a factory: the RFI can mess with sensors, which are everywhere in most factories.
Point is, there are fairly easy solutions and it would be great if they'd put more effort into solutions and less effort into PR BS and lobbying.
(Score: 2) by JoeMerchant on Wednesday May 24 2023, @05:05PM (2 children)
I agree, there are techniques that _help_, but a 300hp drive motor is a slightly bigger problem than a washing machine.
In my field we have to comply with pretty strict emissions standards for in-hospital use. Oftentimes we'll employ all those "simple tricks" and go to testing just to find out that we're 3 or 5 dB over limit somewhere on the band, so we apply some "simple tricks" to push down that peak, and another one pops up... and there we are at $1000 per day at the testing facility that we have to reserve months in advance, playing whack-a-mole with emissions spectra.
The most impressive "design for compliance" I have seen in action is spread spectrum clocks. Instead of having a "ringer" 96MHz oscillator driving your microprocessor's input, use a 92-100MHz spread spectrum oscillator - the peaks, and importantly: their harmonics, just disappear behind the background noise - even in an RF shielded room. Of course, we were using our 96MHz oscillator as the basis of a very precise difference measurement clock, so spread spectrum didn't work for us, and the 3rd harmonic of 96MHz comes in just below the 300MHz "step" in the allowable emissions spectrum, below 300MHz there are much stricter limits than above, and our 288MHz emissions spike would have met the limits if it were at 301MHz... I briefly considered bumping our base clock up to 101MHz to be done with it, but instead a 2nd ferrite clamped on to the accessory cables did the trick. Fun thing was: the device without the accessory cables passed first try, adding a couple of 2 meter antennas outside the shielded box, even if they are shielded and coupled to the box and don't carry any intentional 288MHz content, still doesn't do anything good for radiated power.
🌻🌻 [google.com]
(Score: 2) by RS3 on Wednesday May 24 2023, @05:36PM (1 child)
I've had PCs that had BIOS settings to spread the master clock a bit. Maybe Award BIOS on Gigabyte MB? I forget now...
Regarding testing: it's pretty easy and cheap to do your own testing before you take stuff to the test lab. Years ago I worked in EEG and we had to get some stuff qualified. I used several techniques to pre-test the stuff. What we didn't do was test with a patient connected, but knowing a little about HAM and RFI, I don't think the patient inputs would have radiated much RF as sample rates were pretty low; I forget- and it wasn't my area (but should have been) but maybe 20 Hz? IIRC the PC cases were all metal and had the various beryllium copper things everywhere to "seal" up the cases. We passed with flying colors anyway.
RF is fun stuff. As a kid I used to read the ARRL handbook (still refer to it occasionally) and I was fascinated with (and slightly disturbed by) the sections on RF "leakage" out of fairly well closed up boxes. I think one factor is: like most of life, EEs and system designers are specialized and just don't understand RF stuff much if at all. Companies don't want to hire RF EEs, and those EEs might not understand motor harmonics (but probably would figure it out pretty quickly).
Yes, ferrite beads do great things. They're everywhere. I always wonder why one thing will have them molded into the cable, but another similar product doesn't have one. I fully understand, but I have to wonder if the one devoid of ferrite ferrule should have had one?
(Score: 2) by JoeMerchant on Wednesday May 24 2023, @05:56PM
>Regarding testing: it's pretty easy and cheap to do your own testing before you take stuff to the test lab.
Yes... ish. (After a couple of spectacular failures involving cross country travel) We built our own metal room, sealed the seams with conductive adhesive copper tape, installed a wall of RF anechoic cones, bought some decent gear and did a great deal of pre-testing before going to the certified house to obtain our compliance certificates. Our devices contained intentional oscillators for the purposes of making precise measurements, so we never really cleared the limits by wide margins. Our pre-testing did help, but even if we had calibrated our gear, I doubt it would have correlated 1:1 with what got observed at the certified labs.
>BIOS settings to spread the master clock a bit.
Yeah, first time I tested anything with a spread spectrum clock was a Palm Pilot in the (obviously) late 1990s - you couldn't tell if that thing was on or off by the RF emissions in a shielded room.
>Companies don't want to hire RF EEs
Small ones don't. Brash young startups (cough Tesla cough) probably don't. Once you get big and mature enough, you eventually end up building your own calibrated anechoic chambers and whether your EEs studied RF in school or not, you'll have a couple on staff who know enough to make stuff compliant.
>I have to wonder if the one devoid of ferrite ferrule should have had one?
Look to the certifications. Of course, I have never, ever, seen any practical enforcement channels that would realistically catch whether we put those two beads on our accessory cables or not. I suppose basic ISO-9001 style compliance audits _might_ look at the finished product vs the design on file from compliance testing, but in reality - especially smaller company reality - I'd bet it would average 20 years or more (maybe 200 years or more) before such an audit would catch such a non-compliance. More likely would be, if the emissions were truly grievous, that an end-user would complain about the interference and it would bubble up through channels that way - audit of complaints logs is the most common audit activity. Thing about our two ferrite design was: we were only a couple of dB over without them, nothing anybody would notice in practice, particularly when our peak was at 288MHz and compliant with 300MHz+ limits. But, non-conformance is risk and as a business we'd rather not risk our reputation over a couple of bucks per copy on a device we barely sell 100 copies a year of, on a good year! Now, an offshore manufacturer of something like power tools sold in big box home improvement stores? Hell yeah, I bet a lot of them cut that corner.
🌻🌻 [google.com]
(Score: 2) by owl on Wednesday May 24 2023, @04:34PM (2 children)
Thing is, EM noise such as this is not often isolated to a single band (other than the base frequency of the switching PSU that is). This kind of EM noise is most often wideband interference. AM radios may not be the only thing impacted. A lot of other RF might also be impacted (think CB, or police/fire/rescue bands or other RF bands). AM here may just be the "canary in the coal mine" that is actually warning of a far larger amount of interference that will happen. And as another poster here pointed out, after a certain tipping point of enough EV's without proper shielding/suppression installed on the road, it will be so expensive to turn back that no one in a position to do so will likely be willing to make that call.
(Score: 0) by Anonymous Coward on Wednesday May 24 2023, @05:04PM (1 child)
> A lot of other RF might also be impacted ...
Also think electronic medical devices - insulin pumps, pacemakers, the list keeps on growing.
If cars produce RF that kills someone, the FCC and the car maker will get a wake up call!
(Score: 3, Interesting) by JoeMerchant on Wednesday May 24 2023, @05:10PM
First: it will have to be proven, and that can take expensive years when someone the size of Ford is fighting the other side in our adversarial system.
By the time that proof comes through, there should be dozens to hundreds of additional deaths, if the proof was really true.
Such is our system.
Want to find some nasty RF interference for your implantable medical device? Look no further than the theft prevention tags / deactivation pads / sensors at store entrances and exits. They ring around 80-125KHz, which is a very common frequency range for pacemakers and other implantable devices to run their wireless control interfaces.
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