Good PM reception, bad AM

Hi,

I'm sure this is a tough one, but I get perfect FM radio reception from my aftermarket head unit.  AM reception is awful.  Sometimes the reception is just bad,
and other times you can just tell it's engine noise (it goes with the rpms on the engine).....but then it mysteriously goes away!  Arg.  I don't listen to it that much
(traffic, weather, yankees games:-), but when I do it's a pain.

Any ideas?  Thanks!

Sounds like you may have a bad ground at the base (where the antenna is mounted) of the antenna, especially since you say that it is intermittent. An AM signal requires a good antenna, but FM can work with just about any kind of antenna (coathangers, anyone?). Follow bberman1's advice, try the test antenna. Lousy AM reception with decent FM reception almost always points to a defective antenna or bad ground.

And, remember that your listening enviroment will have an effect on your reception, Am & FM. If you live close to the "Big Apple", you could be suffering from obstructions. Big buildings (and tunnels) are not transparent to AM signals. FM is more forgiving, although depending on how much steel is in the buildings, you can get what is affectionately referred to as "multi-path", where you will pick up echoed (bounced) reflections of the signal. Kinda like seeing ghosts on your TV set, if using a standard TV antenna or rabbits ears. This is not as much of a problem with today's tuners, which will filter out these extraneous signals.

P.S. - I've been out of touch with the business for a couple of years now, but has any company ever designed an inline antenna booster that really and truly works without also amplifying noise?

ay caramba

Well, I don't have a spare antenna readily available....but I'll try the other head unit to at least rule that out.