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/rehook 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.

>Secondly, I would like to know who could the intake. Mine is flaking badly
>and its time to pretty up the engine compartment.

There is some guy working at a magnet lab down in central Florida who does
this as a side business, and who does beautiful work. HEY, DAVE!!

>Finally, I am thinking of going with 18 inch wheels. What would I have to
>be aware of when running these wheels. I understand that Porsche tech
>bulletins frown on this, but I would like to know why.

Check the 928 Specialists web site at

Wally Plumley
928 Specialists