Yup. And because it's a serious and well-known issue, just about all cars sold in the US go through aggressive EMI testing. If only they would test other consumer products as well.
Toyota is actually better about that than most manufacturers, although they issue a whole lot of warnings about not installing high power radio equipment in their cars and they won't provide support if you do. Contrast that with Ford, which has a whole support organization to help folks putting high power radio gear into fleet vehicles (mostly due to the police market).
And I have sadly seen Alabama Pillboxes in the 6KW range. Really nasty output waveform too. And yes, they require a seperate alternator and aren't normally run off a 12V system.
Hams (amateur radio operators) can legally run 1500 watts in the US. And many do so using homebrew mobile installations. At this power level if the installation is not done correctly the car electronics can not only malfunction but be damaged.
But RF can be unpredictable and cause problems at low power also. I have had my cruise control affected with as little as 5 watts when using a VHF or UHF frequency (144, 220 or 440 MHz). Rerouting of cables and/or better grounding usually fixed it.
Nope, that's just part 15 which really just applies to unlicensed radiators that aren't covered under any other service. The old "Class D Citizens Band" is licensed under Part 95 subpart D.
Take a look at section 95.410, and 95.411. If you need more information, take a look at Part 95 subart E regarding the power rules.
The friendly people at the FCC say four watts carrier power on AM, or 12 watts PeP on SSB. This means multi-kilowatt linears are not legal. This means using modified 10M ham radio equipment on the CB band is not legal (also due to the type acceptance requirements). Oh yes, "freebanders" transmitting on the broadcast auxiliary frequencies and in the amateur radio band with modified high power CBs are also illegal.
Now, there was a time many years ago when the FCC was actually operated by engineers, and they had people who would come to your home or your vehicle and take your radio equipment away and leave you with a very large fine for illegal operation. However, we now live in an era when the FCC is run by lawyers who are more interested in using radio services as a profit center and they don't actually have many people who have the skills required for enforcement. But this does NOT mean it is legal.
Absolutely. And presumably hams have the skill required to make sure that they are doing this properly and safely.
K4UMI used to have a 1KW CW rig in his pickup truck which he called his "electronic brake" because it substantially slowed the vehicle when he put the key down.
It's perfectly predictable.... and some car manufacturers will tell you specifically what to do and what shielding and leakage current issues will exist. It's not always easy to predict for the end user who may not know where every ground connection in the vehicle is, but the car manufacturers have RF guys who have that information.
You're wrong Scott, part fifteen covers intentional, unintentional and incidental radiators, which includes everything.
The FCC never came to your home and confiscated any equipment without due process, (court action). That includes monetary forfeiture. It still happens to this very day. More so to small companies who operate illegal transmitting equipment and those who import non certified crap from the far East. Go to the FCC web site, look up enforcement actions and read.
I've installed likely hundreds of aftermarket cruise controls - and on front drive vehicles - and particularly with automatic transmissions, there were a LOT that used engine RPM to sense speed.. Compucruise had that option for sure, as did ARA if I remember correctly, and at least one other major manufacturer that I cannot remember right now.. If the transmission downshifted the cruise control immediately shut down, the same as on a standard shift car. ANYTHING that allowed the engine speed to climb quickly disengages the cruise on these units - without requiring a clutch switch if installed on a standard.
I do remember at least one GM X-Car installation that didn't like a HAM radio installation - and another - can't remember what right off hand - that didn't like the old mobile telephone system installation.
Not necessarily - you don't know what the amplitude of the transmission is. It might not be 12 volts..Also the efficiency of the transmitter. The output of an Icom 2200 is 65 watts. It runs on 13.8 volts and draws 15 amps during transmit and .8 on standby - so 14.2 amps at 13.8 volts - or 196 watts for about 30% efficiency......
All in your experience mabee - but there were a whole LOT that used magnets on the driveshaft instead of tapping into the speedo - and quite a few that used the engine tachometer signal.
I've installed hundreds of them. Likely 50 or more with the engine tach input - and those from at least 3 manufacturers. Compu-Cruise was one, ARA and Dayna I THINK were two others - I know we installed a fair number of each of them.
Actually on a standard transmission it worked just great.. On an automatic it wasn't any worse than a lot of today's OEM systems which also "fall out" on a downshift. Only drawback was the "resume" was no good after a shift.
It would work just as well as the setup on my car (a standard), at least until the clutch starts to go. But the cool thing is that my car will maintain the same speed if I upshift and reengage the cruise control (although I why I would want to be in 3rd gear at 65 mph is another question).
did you notice the 1979 LTD ad? haha, brought back memories of my silver 1985 crown victoria 2-door ... my first car ;)... only 2 door around that i remember seeing
Part 15 is a catchall. It coveres everything that isn't already covered in some other section.
It also has some wording about how products are required to accept interference from legal sources, which is where it becomes important when talking about EMI issues.
Yup, there are a few here and there, mostly due to do with pirate broadcasters and most of the rest of them are in cases where some third party actually tracked the interfering source down.
There are actually fewer enforcement actions on the part of the radio folks than there were in 1975. Needless to say there is also a lot more illegal activity today than there was back then also.
You'll notice that if you go to the FCC web site and look up enforcement actions, you won't see a single illegal CB operator. You'll notice also that if you turn to the third harmonic of channel 19 any evening, you can hear lots of folks talking with their clip-o-matic "linyers." Welcome to the wasteland.
The AM limit is measured as carrier power, so if you're doing a nice 100% modulation then the peak envelope power is actually eight watts because the positive signal peaks are twice the carrier level and the negative peaks are zero.
The SSB limit is actually calculated as peak envelope power directly since there's no carrier with SSB.
So comparing the two is really sort of comparing apples and oranges anyway. But most of the big illegal CB users are on AM... this may change in a couple years when the sunspot peak hits and the skip on 11M gets up to the level where it was in 1978... the CB DX craze may start up again. I hope not...
To sum, p.15 deals with cable, power lines, motors, switching supplies, TV's, wireless products, computers, industrial devices and related interferences to licensed services.
I never mentioned legal or illegal CB operations of which I am not involved with.
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