Consultants say interference in vehicle electronics is possible

dbu'' > wrote:
>Go here to read about the FCC rules which might apply to the situation
>you mentioned. I don't believe there is such a rule regarding "three
>orders of magnitude"
>
><http://www.access.gpo.gov/nara/cfr/waisidx_09/47cfr15_09.html>
>
>Check back when you find it and cite the paragraph so that I can learn
>too.

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.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

AJL > wrote:
>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.

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.

>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.

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.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On 25 Mar 2010 21:06:13 -0400, (Scott Dorsey) wrote:

>In article >, TE Cheah > wrote:
>>15 yr ago I read of 1 car in USA using auto cruise control drtve
>>past a truck using CB radio, this car @ once got unintended
>>acceleration, this driver switched off his auto cruise & ended this
>>problem. He told medias to warn users of auto cruise control
>>against CB radios.
>
>It's not just cruise control... there are a huge number of trucks out on
>the road that are violating the FCC emission regulations by three orders
>of magnitude. Consequently anything that isn't very carefully shielded
>with proper grounding design can have serious problems.
>--scott
Over 100 watts of output from the linear amps on a LOT of highway
rigs.

On Thu, 25 Mar 2010 21:52:28 -0400, dr_jeff > wrote:

wrote:
>> On Thu, 25 Mar 2010 17:28:15 -0500, dbu'' >
>> wrote:
>>
>>> In article >, "TE Cheah" >
>>> wrote:
>>>
>>>> 15 yr ago I read of 1 car in USA using auto cruise control drtve
>>>> past a truck using CB radio, this car @ once got unintended
>>>> acceleration, this driver switched off his auto cruise & ended this
>>>> problem. He told medias to warn users of auto cruise control
>>>> against CB radios.
>>> Maybe fifteen years ago, but EMI suppression has advanced since then in
>>> the automotive industry and many other industries too.
>> There was ONE model of cruise control I heard about that was
>> extra-fussy about CB Radio interference and IIRC it was OK with a 4
>> watt unit installed in the vehicle, but a 100 watt Linear amp in a
>> vehicle within a couple hundred feet could "jam" it.
>>
>> Those cruise control units were VERY primitive compared to anything on
>> the market today. The affected unit was made by ARA if I remember
>> correctly and the problem only occurred if using the engine speed
>> sensor option instead of the magnets on the driveshaft - and that was
>> closer to 20 or 25 years ago (very early 1980s - early Chevy Citation
>> comes to mind.
>
>Cruise control usually used vehicle speed rather than engine speed. If
>the car kicks in a lower gear (e.g., when going up hill), then the car
>would slow down to keep the engine speed constant.
>
>I am not saying that there weren't any cars that used engine speed
>rather than vehicle speed, but I would think that there are few.
>
>Jeff


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.

On Thu, 25 Mar 2010 22:27:52 -0400, dr_jeff > wrote:

>Obveeus wrote:
>> "Scott Dorsey" > wrote in message
>> ...
>>> In article >, TE Cheah > wrote:
>>>> 15 yr ago I read of 1 car in USA using auto cruise control drtve
>>>> past a truck using CB radio, this car @ once got unintended
>>>> acceleration, this driver switched off his auto cruise & ended this
>>>> problem. He told medias to warn users of auto cruise control
>>>> against CB radios.
>>> It's not just cruise control... there are a huge number of trucks out on
>>> the road that are violating the FCC emission regulations by three orders
>>> of magnitude. Consequently anything that isn't very carefully shielded
>>> with proper grounding design can have serious problems.
>>
>> But if this was the real issue it would be much more easily detected and
>> repeatable.
>
>Wow! People are using CB radios with 12,000 W of power. That would
>require a 1000 AMP alternator just for the radio (12 V x 1000 A = 12,000
>W). Note: the FCC limit is 12 W and 3 orders of magnitude is 1000 (10 x
>10 x 10).
>
>Jeff

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......

On Fri, 26 Mar 2010 08:36:04 -0500, "E. Meyer" >
wrote:

>On 3/26/10 8:06 AM, in article ,
>"Mark Olson" > wrote:
>
>> E. Meyer wrote:
>>> On 3/25/10 8:52 PM, in article
>>> , "dr_jeff" >
>>> wrote:
>>
>>>> I am not saying that there weren't any cars that used engine speed
>>>> rather than vehicle speed, but I would think that there are few.
>>
>>> Every car I have owned, starting with the 1960 Chrysler Imperial, has been
>>> equiped with cruise control. They are/were all designed to regulate vehicle
>>> speed, not engine speed. I can't remember any instance of a system that
>>> attempted to regulate engine speed, though I do remember some aftermarket
>>> kits in the 60's & 70's that were simple mechanical throttle controls.
>>
>> No one was claiming any factory cruise control worked by keeping engine
>> speed fixed. Aftermarket cruise controls had that option though, and for
>> cars with standard transmission it was a reasonable choice to tap off the
>> coil signal rather than affix magnets to the driveshaft. The only down-
>> side was if you set the cruise to 60 in 5th gear, and resumed in 4th you'd
>> be doing 70 or so, depending on gear ratios.
>>
>All the aftermarket kits (as well as factory add-on kits) I encountered for
>manual shift cars all passed the speedometer cable through the unit for
>speed sensing and added a second cut off to the clutch pedal (along with the
>brake pedal cut off present on automatic trans units).
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.

On 3/26/10 2:51 PM, in article ,
" > wrote:

> On Thu, 25 Mar 2010 21:52:28 -0400, dr_jeff > wrote:
>
>> wrote:
>>> On Thu, 25 Mar 2010 17:28:15 -0500, dbu'' >
>>> wrote:
>>>
>>>> In article >, "TE Cheah" >
>>>> wrote:
>>>>
>>>>> 15 yr ago I read of 1 car in USA using auto cruise control drtve
>>>>> past a truck using CB radio, this car @ once got unintended
>>>>> acceleration, this driver switched off his auto cruise & ended this
>>>>> problem. He told medias to warn users of auto cruise control
>>>>> against CB radios.
>>>> Maybe fifteen years ago, but EMI suppression has advanced since then in
>>>> the automotive industry and many other industries too.
>>> There was ONE model of cruise control I heard about that was
>>> extra-fussy about CB Radio interference and IIRC it was OK with a 4
>>> watt unit installed in the vehicle, but a 100 watt Linear amp in a
>>> vehicle within a couple hundred feet could "jam" it.
>>>
>>> Those cruise control units were VERY primitive compared to anything on
>>> the market today. The affected unit was made by ARA if I remember
>>> correctly and the problem only occurred if using the engine speed
>>> sensor option instead of the magnets on the driveshaft - and that was
>>> closer to 20 or 25 years ago (very early 1980s - early Chevy Citation
>>> comes to mind.
>>
>> Cruise control usually used vehicle speed rather than engine speed. If
>> the car kicks in a lower gear (e.g., when going up hill), then the car
>> would slow down to keep the engine speed constant.
>>
>> I am not saying that there weren't any cars that used engine speed
>> rather than vehicle speed, but I would think that there are few.
>>
>> Jeff
>
>
> 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.
>

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

> 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.

On Fri, 26 Mar 2010 15:43:02 -0500, "E. Meyer" >
wrote:

>On 3/26/10 2:51 PM, in article ,
" > wrote:
>
>> On Thu, 25 Mar 2010 21:52:28 -0400, dr_jeff > wrote:
>>
>>> wrote:
>>>> On Thu, 25 Mar 2010 17:28:15 -0500, dbu'' >
>>>> wrote:
>>>>
>>>>> In article >, "TE Cheah" >
>>>>> wrote:
>>>>>
>>>>>> 15 yr ago I read of 1 car in USA using auto cruise control drtve
>>>>>> past a truck using CB radio, this car @ once got unintended
>>>>>> acceleration, this driver switched off his auto cruise & ended this
>>>>>> problem. He told medias to warn users of auto cruise control
>>>>>> against CB radios.
>>>>> Maybe fifteen years ago, but EMI suppression has advanced since then in
>>>>> the automotive industry and many other industries too.
>>>> There was ONE model of cruise control I heard about that was
>>>> extra-fussy about CB Radio interference and IIRC it was OK with a 4
>>>> watt unit installed in the vehicle, but a 100 watt Linear amp in a
>>>> vehicle within a couple hundred feet could "jam" it.
>>>>
>>>> Those cruise control units were VERY primitive compared to anything on
>>>> the market today. The affected unit was made by ARA if I remember
>>>> correctly and the problem only occurred if using the engine speed
>>>> sensor option instead of the magnets on the driveshaft - and that was
>>>> closer to 20 or 25 years ago (very early 1980s - early Chevy Citation
>>>> comes to mind.
>>>
>>> Cruise control usually used vehicle speed rather than engine speed. If
>>> the car kicks in a lower gear (e.g., when going up hill), then the car
>>> would slow down to keep the engine speed constant.
>>>
>>> I am not saying that there weren't any cars that used engine speed
>>> rather than vehicle speed, but I would think that there are few.
>>>
>>> Jeff
>>
>>
>> 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.
>>
>
>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.
>
>> 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.

Scott Dorsey wrote:
> dr_jeff > wrote:
>> Wow! People are using CB radios with 12,000 W of power. That would
>> require a 1000 AMP alternator just for the radio (12 V x 1000 A = 12,000
>> W). Note: the FCC limit is 12 W and 3 orders of magnitude is 1000 (10 x
>> 10 x 10).
>
> Nope, FCC limit is FOUR watts.
>
> 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.
> --scott

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

E. Meyer wrote:
> On 3/26/10 2:51 PM, in article ,
> " > wrote:
>
>> On Thu, 25 Mar 2010 21:52:28 -0400, dr_jeff > wrote:
>>
>>> wrote:
>>>> On Thu, 25 Mar 2010 17:28:15 -0500, dbu'' >
>>>> wrote:
>>>>
>>>>> In article >, "TE Cheah" >
>>>>> wrote:
>>>>>
>>>>>> 15 yr ago I read of 1 car in USA using auto cruise control drtve
>>>>>> past a truck using CB radio, this car @ once got unintended
>>>>>> acceleration, this driver switched off his auto cruise & ended this
>>>>>> problem. He told medias to warn users of auto cruise control
>>>>>> against CB radios.
>>>>> Maybe fifteen years ago, but EMI suppression has advanced since then in
>>>>> the automotive industry and many other industries too.
>>>> There was ONE model of cruise control I heard about that was
>>>> extra-fussy about CB Radio interference and IIRC it was OK with a 4
>>>> watt unit installed in the vehicle, but a 100 watt Linear amp in a
>>>> vehicle within a couple hundred feet could "jam" it.
>>>>
>>>> Those cruise control units were VERY primitive compared to anything on
>>>> the market today. The affected unit was made by ARA if I remember
>>>> correctly and the problem only occurred if using the engine speed
>>>> sensor option instead of the magnets on the driveshaft - and that was
>>>> closer to 20 or 25 years ago (very early 1980s - early Chevy Citation
>>>> comes to mind.
>>> Cruise control usually used vehicle speed rather than engine speed. If
>>> the car kicks in a lower gear (e.g., when going up hill), then the car
>>> would slow down to keep the engine speed constant.
>>>
>>> I am not saying that there weren't any cars that used engine speed
>>> rather than vehicle speed, but I would think that there are few.
>>>
>>> Jeff
>>
>> 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.
>>
>
> Boy, that's one sucky setup. Useless from any practical standpoint.

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

>> 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.
>