On Feb 12, 4:40 pm, Nate Bargmann
wrote:
It doesn't take much. Back in the early '90s a group of us were returning
from a hamfest and I was riding in the back seat of one guy's late '80s
Ford something or other (Crown Victoria, maybe?). I was using my HT to

If something is sensitive to RF, it probably won't take much to cause it
to malfunction. The fact is that nobody does RF shielding or protection
for consumer electronics, so there is no set power limit below which a
device may not be affected.


The increased prevalence of EMI/EMC problems means that modern cars
are MUCH better about this. Almost all new cars go through a fairly
rigorous test program for immunity from radiated fields. Nobody wants
to have the engine or braking control systems fail when the police car
next to them calls home on their VHF low band radio. There's rafts of
SAE specs for this, but I don't recall the field strengths. Several
hundred volts/m though, is what I think.

Aftermarket addons (stereos, nav systems, etc.) aren't nearly as good
on the account. Some automotive equipment is exempt from Part 15 (for
instance, the nifty OBD II readers are pretty good RFI emitters...)