Radio transceiver effects on car electronics

RFVSWhen I first began experimenting with VHF/UHF radios, I quickly discovered the unwanted effects of radio signals on electronics in my environment. A simple 10 watts transmission in the 2m or 0.70 cm bands would activate motion detection lights in a 20 meter radius, mess up my home alarm controllers and at some point, trigger my neighbour’s smoke alarm. This was an interesting phenomenon, but as I was about to place this VHF/UHF transceiver in my own car, I wonder how it would interact with the cars’s electronics. This chronic will discuss potential effects of RF to vehicle electronics.

First question which came to my mind is: “Can you apply enough RF energy to stop a car dead in its tracks?” Googling around quickly brought me to Naval surface warfare white papers describing the RFVS (Radio Frequency Vehicle Stopper) devices. In a nutshell, these military RFVS devices can blast enough radio waves to completely paralyze an oncoming vehicle.

RadioVanUpon reading more on RFVS topic, I found out that manufacturers of such devices have a hefty hurdle to overcome to manufacture an effective RFVS device. Their problem is that no two vehicle is the same and different vehicles will react differently to different RF bursts. In other words, a strong burst of RF signal could stop a Toyota sedan in its tracks, but not a GM pick-up truck.

The way they went about resolving this issue was to create a multi-frequency radio-freqency vehicle stopper (MFRFVS). If you focus enough RF energy of various wave length to a vehicle, you increase dramatically the chances of finding the right set of frequencies which will disable that vehicle’s electronic and/or it’s ability to operator normally. Ok, so what are the chances you will come across such warfare device? Unlikely for most of us.

So what about an Amateur Radio? Can a vehicle installed Amateur Radio have an impact on the vehicle its installed in? The short answer is, Yes, it can and will. The question is “to which extent”? What type of equipment/installation will affect which kind of car/electronics? That’s the problem, no one has really compiled enough data to effectively be able to answer all to possible RF/Vehicle possible combinations.

anechonic and carsHowever, on can reasonably conclude that car manufacturers test their products against exposition to outside RF energy to prevent failure or damages. Some manufacturers of luxury cars will most probably do extensive research on this subject and make necessary manufacturing adjustment to render their product less susceptible to RF signal using anechoic chambers, unfortunately, other manufacturers will do minimal efforts, barely enough to receive the necessary certification to be able to export their products to other countries.

This brings us again to the question: how does an Amateur radio operator know if radio installation in his vehicle will or will not affect his car ability to operator properly? Well, an Amateur Radio operator cannot answer with 100% certainty that question, however there are some basic rules and principals he can rely on to install radios in his vehicle with piece of mind.

First, installing a mobile antenna over the car instead of on its sides helps direct RF signals away from the car’s electronics. Second, using lower output wattage on the radio helps keeping potential adverse effects on electronics to low levels. Third, properly grounding the radio equipment and antenna to the vehicle will help the whole car structure become part of the antenna instead of being par of the problem.

electromechanical assemblyOther than these three rule of thumbs, there is no way to know of sure if using an Amateur Radio in a car can have immediately or long term effects on the car’s ability to operate properly. I often hear operators laughing at the fact that operating an HF rigs in their cars, at several hundreds of watts, often have adverse affect on the operation of their car, such as light flickering, engine stuttering or electronic gauges or sensors spiking with wrong information. Such an adverse attitude toward operating a vehicle safely makes me wonder about the competence of these operators.

To this day, I have not seem a shred of evidence that operating my VHF/UHF radio in my vehicle has any negative effects to my car’s systems, electronics or instrumentation, but I suspect it does have a slight impact on some sensors or electronics, but all appears to operate within acceptable norms. My car is a 2002 SUV with a fair amount of modern electronics. I suspect the manufacturer of my vehicle did their homework in protecting critical components against EMI, but I must admit, over the past 3 years, I had to use an ODBII reader to clear a few unexplained car computer codes. Once cleared, the error codes didn’t return, telling me that the reported problem was never there, but possibly induces into the car’s computer somehow. As I’m currently shopping for a replacement for my car, I’ve stumbled on a new set of problems. Newer cars have a whole lot more electronics than 2012 cars and that makes me worried about wanting to re-install an Amateur Radio into a new vehicle.

A luxury SUV had so much gizmos, gadgets and sensors that I promptly asked the sales person if he had any knowledge of restrictions on installing 3rd party transmitters in these high-end vehicle? I quickly realized that I’ll have to dig the truth for myself as the salesperson probably didn’t even know the colour of the tie he was wearing.

car consoleIn today’s modern cars, even low-end models can include Bluetooth, remote access, several type of radio systems (AM/FM, HDFM, Satellite), and more often than not, electronic components control major systems in the car, such as fuel injection, engine operation, steering, braking and every car security systems. Some high-end cars event have the capability to control steering or brake in cases of emergencies, but all depend on multiple sensors and electronics. Future cars will possibly fully control and steer themselves all the way to your destination. How much RF susceptible sensors and electronics will this require?

I cringe at when I hear that Toyota has issues with the acceleration pedal controlling the engine’s throttle remotely. REMOTELY? You mean the accelerator pedal transits its telemetry to the engine via RF signals? Well, not quite, Electronic Controlled Throttle (ETC) uses sensors and computers to determine position of the accelerator pedal to determine what is requested of the engine’s throttle, also controlled electronically. This replaces the “old-school” mechanic linkage (Throttle cable) most of us are used to. But still, is a computer decides how much throttle is requested from the engine is blasted by a good dose of radio-signal, at the right frequency, do you think it could have adverse effects on the safety of its occupants? I would at least think about these potential issues for a minute or two before installing transceivers in a car packed with electronics.

car computer 2I know of a few operator who installed large HF antennas & transceivers in high-end luxury vehicles and have not claimed any adverse effects on their vehicle’s ability to function correctly. Good for them. You can always consider the possibility of installing a transceiver in your car for listening purposes, and only operate them while parked. This will virtually assure the safest way of operating a mobile radio in your car, but could still have adverse affects on some of your car’s components in the long term.

In conclusion, I feel that if an operator follow the 3 rules of thumbs mentioned above, he should not encounter ill effects of his vehicle’s ability to operator properly. However, Radio transceivers can and will affect some brand, model or type of vehicle at various levels. I read some people’s blog confirming having serious problems with their cars while operating an Amateur Radio in their cars. What these blog didn’t say was how their transceiver was installed in their car. I sincerely believe that if you don’t use any of of car’s existing wiring, properly ground all you installation to the car’s chassis, never exceed the transceiver’s recommended operation levels, you should never have any major problems operating an Amateur Radio in your vehicle.

What I’m worried about is today’s advanced car electronics and the ability to “hack” into the car’s electronics remotely by individuals. You don’t even need to use key to start a car these days, just by being in proximity of the car can let you operate all of it’s functions. A few colleague event showed me how they can operate some of their high-end car’s function via the internet, using a smart phone. At LasVegas’ DefCon 21, some computer hackers demonstrated how easy it was to hack into a Toyota Prius 2010′s computer and fool the car control systems into believing anything they pretty much wanted , event change the car’s transmission setting, braking and steering capabilities while the car was moving. It’s just a question of time before they’ll be able to hack into your car from anywhere in the world. You can place your bets on that.

The second pet peeve about installing an Amateur Radio in a modern car is the often complete lack of room to install any components anywhere. Remember the good olds days when you could mount a huge CB radio under the glove box? Well my friends, these days are long gone. With moulded plastic consoles and space rationalization, today’s car are unfriendly to any third party device installation. But operators always find a way regardless of look and feel which makes them absolute hobbyist.

At this point, I always like to place a few demonstrative videos to illustrate the point of my articles. Unfortunately, I found nothing in the world of video clips that relates to EMI effects on cars. However, the ARRL has a page on Auto Manufacturer’s policies in regards to Amateur Radio installation in cars. Manufacturers don’t say much, just that that don’t recommend installing radios in their vehicles.

Hope my enjoyed my point of view.


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