Skoda Fabia Mk1 - Weak Signal on FM and no AM Signal After Changing

Honest John Back Room » Technical matters
View Threaded
Mon 19 Mar 2012 16:32
Skoda Fabia Mk1 - Weak Signal on FM and no AM Signal After Changing - squibsquib

Edited by squibsquib on 19/03/2012 at 16:39

Reply | Report as offensive | Link
Mon 19 Mar 2012 16:39
Skoda Fabia Mk1 - Weak Signal on FM and no AM Signal After Changing - squibsquib

I recently changed the base and aerial of my fabia I to an amplified base. The last one was not. I have I took a switched Positive to the base for power and presume the Amp gets power from the Car Chassis. I just done a straight swap and the signal is still very weak on FM and none on AM. Have you got to earth the aerial at the base as well? I.e. get a serrated washer so it cuts through the paint. I thought the Earth from the Coaxial cable would be enough to power it. Any Ideas? No instructions came with the aeriel

Reply | Report as offensive | Link
Mon 19 Mar 2012 18:24
Skoda Fabia Mk1 - Weak Signal on FM and no AM Signal After Changing - elekie&a/c doctor

what has been done so far seems ok.I would plug an aerial directly into the back of the radio and see if that improves the signal.It could be a fault in the co-ax lead up to the roof.The aerial base should earth thro the nut/washer where it bolts to the underside of roof metal.hth

Reply | Report as offensive | Link
Mon 19 Mar 2012 18:37
Skoda Fabia Mk1 - Weak Signal on FM and no AM Signal After Changing - squibsquib

what has been done so far seems ok.I would plug an aerial directly into the back of the radio and see if that improves the signal.It could be a fault in the co-ax lead up to the roof.The aerial base should earth thro the nut/washer where it bolts to the underside of roof metal.hth

I think the roof is painted in the inside and I didnt take any paint off for an earth at the amplified base side. Do you think I should take the aerial out and try scrapping the paint off or use a serrated washer to cut thru the paint?

Reply | Report as offensive | Link
Mon 19 Mar 2012 21:01
Skoda Fabia Mk1 - Weak Signal on FM and no AM Signal After Changing - VR6

Why did you change the aerial? Were you getting poor reception with the old one?

Have you got the standard headunit, or an aftermarket one? I ask as on all the VW's I've owned require a aerial signal attenuater like one of these: http://www.nexxia.co.uk/product.asp?section=&product_code=PC5-52

(If link above doesnt work, search for PC5-52 on nexxia.co.uk)

Without it, on my VW's I get no reception on MW whatsoever. May be similar for Skoda cars too.

Fits between the end of the aerial cable and the headunit. The original headunits in VW's don't need one, as its built into the headunit, aftermarket ones dont have it built in.

Edited by VR6 on 19/03/2012 at 21:03

Reply | Report as offensive | Link
Mon 19 Mar 2012 21:32
Skoda Fabia Mk1 - Weak Signal on FM and no AM Signal After Changing - Big John

I thought the Fabia already had an aerial amp? Is it faulty or is it not being powered by the head unit through the aerial lead.

When an inline amp is not working you loose AM and FM becomes weak.

Reply | Report as offensive | Link
Mon 19 Mar 2012 22:16
Skoda Fabia Mk1 - Weak Signal on FM and no AM Signal After Changing - squibsquib

The reason I changed it was I was getting a very weak signal from my old one after the heavy rain so I presumed it was the aerial. I bought one with a built in amplifier in the base of the aerial as I was advised too but when I took the old one out there was no other wires coming from the base apart from the coaxial cable for the signal. This told me that the base was not amplified. Not unless there is an Inline Amplifer somewere. When I bought the new Amplified aerial (Which is suitable for Skoda, VW and Seat) it came with new coxial cable and a cable to run to the positive feed for the aerial amplifier. I installed this but I thought the amp would get the negitive feed from the ground part of the amplifier cable. When I installed it I did not scrap any paint for an earth at the base away for an earth. I did end up finding a serrated washer a few days later which I think came with the aerial. This would have scrapped aay the paint from inside of the roof and grounded it properly. Only thing I can think of is that the amp needs to take its ground from chassis of car as may cause interference by using Coaxial ground. I am going to try the serrated washer and hopefully get a result. I have tested the positive with a multimeter and it is getting 12V. Any ideas would be great.

Reply | Report as offensive | Link
Tue 20 Mar 2012 00:41
Skoda Fabia Mk1 - Weak Signal on FM and no AM Signal After Changing - Peter.N.

If I understand correctly you are feeding 12 volts to the base of the aerial, you cant do that without a filter network or the power feed will effectively shrt circuit the output from the aerial.

Reply | Report as offensive | Link
Tue 20 Mar 2012 15:50
Skoda Fabia Mk1 - Weak Signal on FM and no AM Signal After Changing - squibsquib

Hi Peter. I don't understand your last comment. These is one cable coming out of the base apart from the coaxial cable. I have been told that This should be attached to a switched Positive output which I have done and the Negitive is taken from the Chassis of the car. If it did Short circuit as you mentioned it would have blown the fuse.

Reply | Report as offensive | Link