At 08:31 AM 11/18/00, Mark Reifenberger wrote:
>What would cause my radio to get excellent reception of FM stations, and yet really poor reception of AM stations?  I don't really use the AM much, but when I do, the signals are extremely weak.  It's been like that as long as I've owned it.  I'm hoping it's something simple like a disconnected wire, rather than anything internal to the unit, but I haven't had a chance to check around behind there yet.  Any ideas, or suggestions?

The stock antenna on the 928 contains a small RF amplifier. This amplifier is powered by a small black wire that runs along the antennal lead-in cable. It is VERY, VERY common for POs or unknowing audio installation techs to either disconnect this small black wire, or to hook it to the wrong connection (usually ground!)

The small black wire that powers the antenna amp should be hooked to a 12 vdc source that is on when the radio is on. This connection varies with different radios, but is usually marked as an antenna relay feed or something similar.

Wally Plumley


At 09:26 AM 3/8/01, Patrick A. Leston wrote:
Good day; I must admit I am fed up with the reception afforded me by the stock antenna in the glass of my 1987 S4. Reception is lousy and it makes all the FM stations sound like AM. I would like to know what is the best solution for this short of replacing it with the surface mount.

First thing to do is to check and make certain that your antenna amplifier is hooked up and functional.

1) Get to the back of your radio and find the antenna lead-in. Attached to the lead-in should be a small black wire. This is the power supply wire for your antenna amp. It should be hooked to a switched 12 vdc source, such as the "power antenna relay" terminal on the radio. Note that the same 12 vdc source is needed to trigger an out-board audio amplifier

2) If the black wire is not hooked to a suitable 12 vdc source, hook it up. Performance should improve.

3) If the black wire is already hooked to a suitable 12 vdc source, make sure that you really have 12 vdc.

4) If you the black wire is hooked to a good switched 12 vdc source, turn the radio on and tune to an AM station. Unhook the black wire - AM reception should get noticeably worse.  Hook it back up - the reception should improve. If it does so, the problem isn't your antenna amp. If there is no change when you unhook/re-hook the amp, the amp is probably bad and should be replaced.

And, if the surface mount is the only solution, who would do that job here in the Central Florida area (Orlando).
Installing the roof-mount antenna is not as simple as it might appear. Make sure that your selected installer knows what he/she is doing.

Check the 928 Specialists web site at

Wally Plumley
928 Specialists