Radio Reception problem

byte

Just a quick question (I hope)!

I drive a 95 Corsa and had the head unit changed (to a class Pioneer DEH7000MP) but the radio reception has been below par. National stations seem to work well enough most of the time though local radio is generally a poor effort. also, LW and MW are non existant which is a shame, as I'd like to try receiving 5 Live MW.

Anyway, over the weekend, i removed a plastic panel in the car which gives access to where the beesting aerial is bolted underneath. I noted that along with the coaxial cable, is a single electrical wire too entering the base of the aerial. As there is a seperate wire, am I right in thinking that the aerial is an amplified one? If so, this would probably explain the reason for poor reception (amp isn't powered). As the aerial is grounded to teh body of the car, would I be right in assuming the other wire is a live wire and should be connected to the Remote wire in teh stereo for example? Or does amped antennae input less than 12V+? I think the aerial is still the standard beesting that came with car since manufacture.

Any help appreciated

Atomic Pineapple

noticed the same kind of effect with all my head units (have had 3) generally just tweaking the options sorted it out or the reception just seemed to get better by itself

byte

Tried all that. Anyway, it wouldn't explain why LW and MW don't work at all.

I think I should get my hands on a multimeter to see if voltage is already present. If it's present, it could mean the integrated amplifier is knackered

Atomic Pineapple

can you select bewtween LW and MW on the unit?
you should still be able to select them but not get any reception if its the amplifier, shouldnt you?

checking to see if theres voltage there is probably your best option

Neil_Sedaka

byte, on a seperate note did you lose the clock/temp display in the dash when you changed the head unit to a non standard Opel one?

byte

draffodx: Yes I can change through all the radio bands on the headunit.
Just a hiss on all the freqs though

Neil_Sedaka: No, that part still shows Time|Date|Temp. Doesn't show radio information though which doesn't bother me

Hellrazer

Sounds like an aerial problem alright.Did you fit the unit yourself or get someone else to do it???
From past experience Ive found that some radio fitters leave the aerial connection at the unit end loose because the connection in the European cars is different to Japanese ones(pioneer for example---one is male the other is a female type connector)
The way a new unit is tested upon fitting is by powering it on and selecting preset number 3 which is 98fm on all pioneer units.98fm comes in as clear as a bell and the fitter doesnt bother with the aerial connection.

If you do find that the problem is the aerial is not connected you need an adapter for Euro---Japanese aerial connector(about €2.00).Problem usually shows up as a lack of lw/mw and/or weak fm signal on local stations due to the fact that the national FM stations usually pump out a stronger signal.
Worth a look!!!!!!
Richie

byte

No the aerial cable itself is connected to teh back of the stereo with an adaptor due to the difference in connections you speak of.

Just not sure about the additional electrical wire that goes into the aerial. I'll have to try getting my hands on a multimeter I reckon.

Selik

I have had the same problem with my VW Golf since I got the head unit changed back last summer. I can get perfect reception on all FM stations 99% of the time but all I get is a deep hiss when I switch bands to LW or MW. I too woold like to listen to some BBC stations sometimes (BBC 5 Live in particular) so I would love to be able to get this sorted out. For the record my head unit is a Pioneer one and I had no problems with MW / LW reception before I upgraded my head unit. Is it just a simple matter of taking the unit itself out and connecting two cables together properly? (with the help of an adaptor of some sort obviously...)

John R

There is a special adaptor for vw cars with those stubby aerials to use with aftermarket radios, it connects between the aerial lead and the head unit with a wire going to the ISO connector. Presumably this is the same for Opel, best to check though.

VW adaptor

louie

You don't have a problem with your aerial.
The original radio was built & designed to work with the standard aerial your car was fitted.
When you get an after market head unit on some cars as Opel and VW the reception gets very poor on LW and MW. By replacing the aerial with a longer stick will usually sort out the problem, but in your case OPEL, the aerial is electric, so I don't think you are going to have any luck finding a replacement.

byte

Originally posted by louie
You don't have a problem with your aerial.
The original radio was built & designed to work with the standard aerial your car was fitted.
When you get an after market head unit on some cars as Opel and VW the reception gets very poor on LW and MW. By replacing the aerial with a longer stick will usually sort out the problem, but in your case OPEL, the aerial is electric, so I don't think you are going to have any luck finding a replacement.

Thanks for clarifying it a bit. If the aerial is electric, does this mean it's amped? What if I were to replace the current beesting aerial with a non-electric beesting (I realise that beestings were never much good with AM)?

louie

It was meant to, but they never worked right.
Try replacing that with a longer one and see if it does the job.

byte

OK, thanks!

Ive just realised how hard it is to find an online store that sells car aerials so I'll make a trip to local auto spares soon.

ZENER

Its possible there is an antenna preamp to compensate for the small antenna. It would be a wideband one if it has to give gain for LW up to VHF though, have you tried connecting a supply to the wire, maybe a 9V battery would be safe to start with as its unlikely to damage anything but should be enough to get the amplifier going.

Probably clutching at straws here but is there any externally accessible internal adjustments for antenna adjustment. Earlier AM only radios had a variable cap for adjusting the antenna length (virtual). Check the manual, it might mention it somewhere.

I have info on this somewhere, Ill try to dig it out tomorrow!

Tinky