w123 AM radio reception

[JHZR2]

Hi,

I have a 1983 300D with original becker grand prix tape deck. The radio is fine, and the overall system allows for pretty good quality dconsidering its age.
The only problem I haveis with am radio reception. It is HORRIBLE. FM radio reception is fine, and with the antenna fully extended AM reception can get marginally better, but no matter how I set the antenna length, I cant get a good constant signal.
While FM reception is equal to my digital radios, AM reception leaves much to be desired, especially compared to my digital radio in my 98 chevy.
Is there some way I can increase my AM receiving range?
Thanks,

JMH

[donbryce]

I've just finished a self-taught crash course in antenna reception, so here's some suggestions.
Get another antenna, a standard manual pull up is fine, and connect, making sure the outer casing (not the mast) is grounded. If the reception improves, the problem is probably in the antenna or the connection of the lead to it.
While the lead is disconnected from the antenna itself, use a multitester on OHMs setting, touch the tiny center pin and the outer casing on the antenna (if the lead is a stock screw-on design). There should be no continuity. If there is, something has shorted the mast to the inner lead wire connection, and this will destroy the reception, especially AM.
Do the same to the lead (inner socket or pin to outer casing/shielding), and also check that the center wire in the coax isn't grounded, and that the outer shielding is.
Check that there is continuity in the lead itself, from the antenna end to the radio end, both outer and inner wire/shielding.
If none of these tests reveal a problem, it's probably the radio itself, or maybe someone has changed the antenna and it doesn't work very well with the stock radio.

[JHZR2]

Thanks!

Ill run those tests on my equipment.

JMH

[tecqboy]

An older radio like that may have an antenna "trimmer" adjustment to improve AM reception. Check in the radio manual or with Becker. I think www.beckerautosound.com You extend the antenna to the longest it will go, then tune to a high frequency, like 1400 KHz, and adjust the trimmer for loudest signal.