Consultants say interference in vehicle electronics is possible

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.

Over 100 watts of output from the linear amps on a LOT of highway rigs.

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.

Boy, that's one sucky setup. Useless from any practical standpoint.

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.

MY bad. The 12 W limit is for SSB transmissions.

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).

Jeff

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

hehe, page 19, datsum, civic corolla among the top recomended used cars even back in 1979.

I kindda want a winston or camel too...

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.

--scott

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...

--scott

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.

I did, as did the person whom I was replying to in the message that you flamed. That was the whole point of the message you were replying to.

--scott

That's not true, SSB is suppressed carrier. Carrier wave is present, but suppressed.

It may or may not internally generated, but it's not being transmitted. if it _were_ transmitted, it would create an annoying beat note on playback unless the receiver BFO was right on the mark.

But, more importantly, it counts against your total output power... any residual carrier leakage is wasted power. That's bad, especially when the legal limit is so low you want as much as possible of your signal to actually be carrying information.

Type acceptance requirements for aircraft, marine, and commercial SSB gear have limits for how much residual carrier leakage is allowed, and it's very little. Amateur radio operators don't have any such requirements but they are expected to know what they are doing. I don't know what the CB type acceptance requirements are like.

--scott

That also is not true. The suppressed carrier wave is being transmitted, but numerous decibels down from the maximum power being radiated. You might hear a carrier wave if the transmitter was physically close, transmitted signal very strong, but at some distance you may not hear it, signal weaker. This is just academic because all SSB transmitters today have superior carrier suppression. That was not the case years ago.