VHF interfearing with car computer

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8K10F1E

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Has anybody ever had any problems with ham radio RF interfering with other electronics in their vehicle?

I recently installed a MAF calibrator into my truck (it optimizes the air/fuel ratio for performance, not economy) and it's bugging out when I transmit with my VHF radio. The engine actually stalls.

URD MAF is sensitive to RF - YouTube

Anybody have any suggestions to how I can prevent this from happening?
 

K9WG

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Use to be a big problem when microprocessors were first used in vehicles. In fact some of the car manufacturers had warnings in the owners manual about the car possibly shutting off if a ham radio was installed. Haven't heard anything about it lately. You might try installing some filtering on the power harness and some ferret beads on the other wires. also make sure it is grounded well.
 

fineshot1

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Has anybody ever had any problems with ham radio RF interfering with other electronics in their vehicle?

I recently installed a MAF calibrator into my truck (it optimizes the air/fuel ratio for performance, not economy) and it's bugging out when I transmit with my VHF radio. The engine actually stalls.

URD MAF is sensitive to RF - YouTube

Anybody have any suggestions to how I can prevent this from happening?
You would do best to contact the manufacture of the MAF calibrator device
and seek their tech support as they must have had this run by them before.
It would be difficult to believe that this is the first time this has happened to
their electronics as many vehicles have two way radios installed in them.
 

N9NRA

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This happened to me and another ham when we were headed to Dayton last year with his camper, any time we would transmit with his mobile the computer would "throw codes" (start showing diagnostic codes for various engine problems that it thought were there but weren`t). Only thing i could recomend is to have a look at how the coax from the antenna is run, if it`s too close to the engine`s computer moudule that could cause issues. Good luck. 73. N9NRA
 

krokus

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There are a number of possibilities.

Is the VSWR 3:1, or less? Is the antenna in good condition? Is the coax a good quality, with a 100% shield? Is the antenna and/or coax near any of associated wiring for the MAF? Is the VHF radio a good quality brand, in good condition, thereby lowering the chances it it sending RF out on the power feed? Is the interference frequency selective?

As already mentioned, ferrite beads and cable routing can make a huge difference. Turning down the transmit power can make a big difference.
 
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kb0nly

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Seems like every time i encountered this is was two things... Proximity of the device to the RF field/antenna and its internal shielding, and SWR of the antenna.

My Garmin Nuvi is sensitive to UHF, its the only band that bugs it, i talk on UHF and it acts like external power was shut off to it and it goes into the standby timer and shuts off. I have tried everything on it, filtering and bypassing, nothing helps.
 

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kb0nly said:
Seems like every time i encountered this is was two things... Proximity of the device to the RF field/antenna and its internal shielding, and SWR of the antenna.

My Garmin Nuvi is sensitive to UHF, its the only band that bugs it, i talk on UHF and it acts like external power was shut off to it and it goes into the standby timer and shuts off. I have tried everything on it, filtering and bypassing, nothing helps.
My Nuvi would do the same but when I transmitted on my commercial Vhf mobile when using my aprs 1/4... Now with a NMO wb with a properly tuned whip it is fine.
 
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