I own a 1997 Camry V6 with 5 speed manual xmission. I had ignition
RFI on the car radio medium wave band. I like to tune in distant
stations on ground wave, especially those at the low end of the band.
Ignition noise wiped them out. I yanked out the radio from the dash
(this was around 8 years ago) and found that the radio's ground
consisted of a skinny wire in a cable bundle that included 12 v. and
speaker cables, essentially everything except the low Z coaxial feed
to the antenna. The bundle was connected to a plastic modular plug.
I cut and punched 2 inch wide copper strap because I had a lot of it,
and bolted one end to the fire wall where I found an unused hole. I
think the fire wall had these tapped holes so I only needed a bolt.
I strapped the other end to the metal side of the radio. That solved
my problem but then it gradually returned. The second problem turned
out to be the coax male that plugged into a recessed jack on the back.
Car radios all mate with a plug that has a center pin and the shield
is a pair of springs that bow out on each side of the plug body, sort
of like a banana plug. These get weak and lose contact. gently
bending them back out and plugging the connector back in solved the
problem. A better plug and jack is needed though, something that
threads on. The feedline is low Z line I believe, just a few ohms
impedance.
Sometimes the shield open connection is at the antenna but in my case
it was okay.
Rob
K5UJ
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