Reply With QuoteCouple of questions just to clarify: does your radio show signal strength and mono/stereo? Does it flip between mono and stereo if the car isnt moving? Is it like that on all FM stations?Originally Posted by ss2115
Big Time Poster
Radio antenna?
Hi. My radio constantly flips between stereo and mono with the accompanying change in volume and quality even though I drive in the metro area 99% of the time.
I realise that my car (1993 525i Touring) has the diversity antenna in the rear side window.
Whats the most popular or common solution to this problem?
Is it a matter of an inline signal amp, or changing to a different antenna perhaps?
What have most people found works best please?
ss2115.
BMW 525i Touring - 1993 (current drive car).
DS23 Citroen Safari - 1974 (restoration and modifications).
Golf MkIII - 1997 (fun car and daughters learn-to-drive car)
3 Grand Master
Couple of questions just to clarify: does your radio show signal strength and mono/stereo? Does it flip between mono and stereo if the car isnt moving? Is it like that on all FM stations?
Major Contributor
I have the same problem! I put it down to the fact that my windows are tinted but if you are getting the problem as well I guess not. I've tried running a cable straight from the aerial to the stereo, no difference. I've also tried an internal window aerial with a booster which is equally as crap. I haven't figured out how to get the side trim panel off to see what below there so I am thinking the only option is to drill a hole in the roof and use a roof mounted one, I'm putting it off because its a bit drastic and there are no guarantees it will be any better!
UK 1997 e34 540iA Touring, 1989 535i Sport - now sold, 1998 Mercedes CLK 200 Coupe
Major Contributor
I take it you guys have no problem with tapes, just to make sure the problem is not elsewhere.
Big Time Poster
Hi. No, there isn't a signal strength meter.
Its definetly flipping between stereo and mono - its like the difference between old AM (no high end quality, flat sounding and no difference left to right) and FM or even almost CD "sounding" - you can hear it seperate into left and right, the high end pops back and the quality jumps up several notches.
No, its only when the car is moving. If I stop in a place where it drops to mono, it stays mono and visa versa. Sometimes I'll be stopped in slow traffic and it drops to mono and then I'll only have to creep a few metres forward and it will spring back to stereo.
Its definetly signal orientated from the antenna.
[I remember having this same problem in a couple of Mazda's many years ago when they tried the rear window track idea in the RX4's (they may have been the first - I don't know) but it used to do exactly the same thing. Their antenna's were big "T" across the rear window above the heating tracks.]
I couldn't tell you if its on every FM station I have memorised because in reality I only listen to three stations in total - one 95% of the time but if there's a song or advert or something I don't like I might change to one of two other stations and then come back later.
But Yes - it happens equally on all three stations that I listen to.
No - it doesn't happen on the tape player - not that I use it much but I had the same idea in case it was a loose connection or something and the tape plays in stereo just fine without a problem.
Last edited by ss2115; 07-10-2009 at 06:41 PM.
ss2115.
BMW 525i Touring - 1993 (current drive car).
DS23 Citroen Safari - 1974 (restoration and modifications).
Golf MkIII - 1997 (fun car and daughters learn-to-drive car)
Grand Master
It could entirely be a problem in the radio itself, and not an antenna problem. Assuming you both still have stock radios. Why not pick up a used one at a breakers and try swapping radios to see if that fixes the problem? I can't imagine that a used stock E34 radio would sell for much of anything.
Cosmos Black/Black 1995 540iA M-Sport
BMW Individual Exclusive Edition, 1 of 65 total, 9/25/95 Build
Major Contributor
This is the third stereo I've had and they have all suffered from the same problem, they have all been good quality Alpine units. CDs are fine, its just the radio for me too.
UK 1997 e34 540iA Touring, 1989 535i Sport - now sold, 1998 Mercedes CLK 200 Coupe
3 Grand Master
If the tape works fine in stereo its not the audio output amps as the tape and radio will use the same ones. As the radio works fine until you move, I'd have to agree that weakening signals are the cause. Of course FM travels by line of sight so if you are surrounded by tall buildings that wont help. But I'd start by having a look at the aerial amp to ensure its even powered up.
Major Contributor
Doesn't the antenna amplifier 'choose' between a few circuits in the rear window? Maybe one of these is interrupted? Any bad spots on the rear defrost?
***- bottom of the page... http://www.bmwe34.net/E34main/Upgrade/Stereo.htm (shrug?)
Last edited by tim eh?; 07-11-2009 at 06:20 AM.
3 Grand Master
I have seen that item before too. But my Kenwood CD player/radio has no problems at all with FM. You could try a different inline amp like this:
http://www.crutchfield.com/S-RZ0SWd7...Amplifier.html
But I would want to make sure it didnt amp up all the white noise as well before I bought one
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