[RFI] RFI issues in electric (or hybrid) vehicles

[Jim Brown]

On 4/13/2012 9:34 AM, Dale Svetanoff wrote:
> Unless gas prices really do
> hit $5/gal, or more, this year, the hoopla over these cars and the
> manufacture of their expensive batteries in new US factories may be just
> that - noise with little substance.

The fundamental limitation of an ALL-electric vehicle is range, which is 
currently limited by battery technology.  Hybrids don't have this 
limitation.

> I did learn one thing about at least some of the hybrids: I did not know
> that a small "auxiliary" battery was used to run 12 VDC accessories.  If
> that is where the radios are to be powered, then one has to wonder how well
> that accessory power buss is decoupled from the main, high power buss, and
> how low of an impedance to chassis "ground" does the overall current path
> represent.

Hopefully, the EEs designing Toyota elecrical and control systems have 
learned something since they built my 2005 Sequoia.  It is HIGHLY 
susceptible to RF on the HF bands, to the extent that a 100W rig on the 
HF bands locks up the computer that runs the motor.  When I bought it 
new, I took it in to K9IKZ's indoor shop (it was winter in Chicago) 
where he helped me run power and install a mount for the antenna.  In 
preparation for the latter, we studied  bonding of the chassis and frame 
with a VOM, and it didn't take long to realize that there wasn't much.

And I will agree with others who have observed that the only serious 
vehicular noise generators I've observed on the road are the inverters 
in big trucks.  It's no wonder these guys have to run power to talk to 
each other.

73, Jim K9YC