gingeRS

Is anyone clued up on car electrics? I have a problem where the radio reception is rubbish in my FRS. I have replaced the aerial and base, to no avail. I have also made a few observations. If sat in traffic and reception is hissy, I switch the engine off and the reception improves dramatically. I also noticed this morning when I started the car, that the reception goes bad 3-4 seconds after starting, and also gets significantly worse when I switch on my HID lamps (aftermarket).

Any suggestions, has anyone had similar problems?

cjwood555

It's a little hard to diagnose without specilist equipment - it could be that the radio is overly EMI sensitive due to poor design, it could be faulty, you could have a faulty alternator.

Is it a standard 6006? If so I'd be looking elsewhere than the radio as this isn't a 'feature'! You could try using a clip-on ferrite core on the antenna lead, but I think it's going to be alternator related.

HTH
Chris

gingeRS

its a poverty spec ford 5000 tape deck....was a stop gap while i chose a new radio

if it was alternator related, how would i resolve it, new alternator or is there some check i could do.

where would i get the clip on ferrite core and waht would this achieve?

cjwood555

The ferrite core supresses EMI interference. CPC, Rapid electronics, Ebay, will do fine.

Alternator wise, it depends if it's just radiating cack but giving a clean output, or whether the output is noisy too. You could get it on a scope to see what the output looks like, if you know anybody with one. Sadly most garages or auto-sparks don't own one.

The three things I'd try are:
- Ferrite as above
- Run a direct earth from radio to chassis (standard wiring goes all over the shop)
- Put a bypass cap in parallel with the radio 12V and ground. 1uF electrolytic will do fine.

Bear in mind though that the 5000 might be suffering from a design flaw or a fault - you may find the issue goes away with a new radio!

gingeRS

cheers for the advice, i have scopes at work but would know what to look for with it

will try that ferrite thing on the radio lead, and running a direct earth. i'm sure its not the radio as the same thing happened on my old pioneer, its defintely the wiring.

switching the HID's on has a significant effect also, nut not sure what i can do about this as i really like having them, and they light the road so much better! maybe i'll try another kit?

cjwood555

Are the scopes you have logging ones? If so get a screen shot or data out showing the FM frequency range (roughly 80 to 110 MHz) - traces at the same gain/scale from the radio antenna fly-lead, same with antenna unscrewed, alterator output and 12v to radio would be a comprehensive way of seeing where the problem starts.

Rsmat

iTrader: (2)

buy a supressor.

martysmartie

iTrader: (1)

It's obviously never always been a problem so your first question should be have you changed anything?

Listen to the type of interference, is it a loud buzzing which increases with engine speed? If so look suspect the alternator (They do have a suppressor but they may have failed) Is it a crackling if so suspect ignition leads, if changed are they suppressed?

Martin

gingeRS

it has always been a fault as long as i can remember the car has always had rubbish FM reception. it is due some ignition leads so will look at them next, i have also ordered the ferrite suppressor as suggested above.

could it be as i'm running non standard leads (blue ones labelled - ford motorsport) but i highly doubt ford made them?

cjwood555

The fact it gets worse with the HIDs on (i.e. more power load) points towards the alternator, rather than the leads. The question is whether it's being radiated or conducted.

If the ferrite doesn't help when on the aerial lead, try it around the 12V radio feed along with a direct earth as mentioned before.


Chris

gingeRS

ahhh ok so its not the units causing the interference as such, its the electrical loading on the system that causes the interference.

i looked in ebay for the ferrite cores and they are availible (mostly from china) in all sorts of sizes...any suggestions?

would it be worth checking the earths on the battery etc? could this affect reception, i have also hear of people having problems with the aerial lead on the mk1 focus, but as it runs along behind the dash along the bulkhead its a real paint to change!

martysmartie

iTrader: (1)

Oh thought it was a sudden thing, never read that so good point as mentioned below about the HID'S when powered on, yes it is possible to get unsupressed leads but the majority are, but as said it's most likely to be alt from said ^^

Martin