Radio problem?
- Thread starter sonicci
- Start date
PlasticMac
Member
Antenna power does not go to the antenna amp via the HU via co-ax cable. It comes from the mini iso, on the HU, switched 12 volts. This supply goes to the antenna amp direct.
Mac.
Mac.
audifan
A2OC Donor
Check the boot floor for water ingress. The water can collect in the radio diversity unit causing corrosion in the unit which then shorts out. Check the battery compartment and the rectangular box area to the right of the battery where the diversity unit is vertically mounted behind. Water ingress is usually from the vents located behind the rear bumper. you will need to remove the rear bumper clean the outer edges of the vents and apply a good thick waterproof sealant all around the outer edges.
Hi @sonicci,
Read this very recent thread it may help with what is called the diversity unit.
Andy
Read this very recent thread it may help with what is called the diversity unit.
Radio reception issues [SOLVED]
Been trawling through the site but not finding the thread that might deal with this, so wondered if anyone can help? Wife's A2 2003 with aftermarket double din radio, which has been in there for a while and working fine, apart from FM radio reception, which comes in and out on R4. The head...
www.a2oc.net
Andy
PlasticMac
Member
Sorry, HU = Head Unit (radio, Chorus or Concert).
I was sure antenna amp power is not supplied via the co-ax cable, but, maybe I'm mistaken ...
Or, the two amps, 8Z0035225, (one each side) connect to another antenna amp (8Z0035225B), and draw their power, via the coax, from there. The antenna amp 8Z0035225B, is powered. (I'm not very familiar with the "Diversity" setup)
I think the radio co-ax goes first to amp 8Z0035225B, then from there to each 8Z0035225.
To check, pull the radio out, but leave iso cables connected, but remove co-ax, and fit a tempoaray antenna, (a lengthe of co-ax, with the outer screen and inner core separated over about a metre, will do), to see if the radio itself is OK.8Z0035225
If so, check amp 8Z0035225B next.
Take a look here:
Mac.
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G
Guest 4123
Guest
In my experience all VW/Audi radios supply 12v to the aerial amp, via the coax. That's why you need one of these:
PC5-52 Signal Separation ISO - ISO for Audi Seat Skoda VW | eBay
This amplified aerial adaptor fits in line with the car's aerial connection and has a built in booster to help increase signal strength. Antenna Adaptors connect your car audio unit to the car's external aerial/antenna.
www.ebay.co.uk
when you install an aftermarket radio. I've tried Sony, JVC, Pioneer, Aiwa, and Pure radios and none have a built-in 12v supply for (and through) the FM coax (the latter does have a 12v supply for DAB). What they do have though is a switched supply for an aerial which you connect to the adaptor.
RAB
Last edited by a moderator:
PlasticMac
Member
@RABIn my experience all VW/Audi radios supply 12v to the aerial amp, via the coax. That's why you need one of these:
PC5-52 Signal Separation ISO - ISO for Audi Seat Skoda VW | eBay
This amplified aerial adaptor fits in line with the car's aerial connection and has a built in booster to help increase signal strength. Antenna Adaptors connect your car audio unit to the car's external aerial/antenna.www.ebay.co.uk
when you install an aftermarket radio. I've tried Sony, JVC, Pioneer, Aiwa, and Pure radios and none have a built-in 12v supply for the FM coax (the latter does have a 12v supply for DAB). What they do have though is a switched supply for an aerial which you connect to the adaptor.
RAB
I agree, I'm wrong on this one, sorry all.
Mac.
Still wondering, there comes coax and from amplifier to wires blue and black ,,,goes to window antenna, co-ax has 0,8v when radio is on,same voltage comes from the radio ,I took radio of and ewerything seems to be original Audi Chorus, there are not any other amplifier at least on the other side ,,,,?
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PlasticMac
Member
The link I posted seems to show there is a central amp, to which the coax from the radio goes, then two coax cables from there to the two amps, one each side.
0.8 volts seems very low for the supply to an amp.
Mac.
0.8 volts seems very low for the supply to an amp.
Mac.
G
Guest 4123
Guest
Is the voltage being measured with the radio on and the coax dis-connected at the rear end? If you're measuring with the coax connected, the measured voltage could be anything below 12v!
RAB
RAB
PlasticMac
Member
Ok I don`´t have diversity unit (should it be near the battery, there are only some kind of balancing weight?) and I also don´t have the second amplifier 8Z0035225B so the coax must come straight from Chorus, I have only one amplifier on the right hand side trim, I think that it is impossible for amplifier to ground from body, it is so well painted? Is something missing?
PlasticMac
Member
The amp gets it's supply via the coax (thanks @RAB), which provides positive (centre core) and negative (screen), so no ground required.
Thinking you've lost the DC supply from the radio antenna socket. Maybe buy an aftermarket supply as described by @RAB to give you an external amp supply?
PC5-52 Signal Separation ISO - ISO for Audi Seat Skoda VW | eBay
This amplified aerial adaptor fits in line with the car's aerial connection and has a built in booster to help increase signal strength. Antenna Adaptors connect your car audio unit to the car's external aerial/antenna.
www.ebay.co.uk
Mac.
