On AM radio, there is often a sound, like a hammer hitting a 55 gal. drum interrupting the program. Does not do it on portable radio carried in the car.

All stations AM?

is the engine running?

for get the portable, some have vastly better a/m radios than any car has. in fact many cars radios a/m OR of horrid quality.

i can tell you why but its boring. (AGC, read up on that)

did you try the radio in car, parked say across town.?

did you try all stations

are you like 1 block away from an AM radio station, overloading yours.

AM radios are basically noise making radios., that is why FM was invented to stop that noise, (i cant hear it so.........?????)

are you listening to far away stations, this is normal

in fact you might hear 2 stations on same channel (freq)

and they will beat against each other.

on case of is in S.Calif where your station is clobbered by high power mexican stations 50,000 watts. strong.

and worse a night, does it get better in the day?



here is my advice, many AM stations have a rebroadcast on FM.

go there and listen. (use SAT radio?)

AM radio is subject to vast sources of noise.

ignition noise., high voltage power transmission line noise.

machinery noises, (electric)

or even illegal transmitters in your hood.



many new cars the AM radio is junk, they use this very cheap

chip inside that does this very poorly, but allows them to say

it has AM. ( for $1 cost)

the FM side is 10x better, or more. move up to FM like we all did back in 1967. (i used to build and sell converters back then)





answering for , all other modes work perfect, but AM radio..