Radio interference!!

[Richn83]

JPC, according to vwnavi some people have this issue because they have the diversity aerial amplifier which switches and amplifies the AM or FM dependent upon the MFD2, but the RNS510 has this inbuilt so see if you have the diversity box, IIRC its under one of the seats.  

The fault code tells that you only have one antenna active.
The car has antenna amplifier as standard.
I also used adapters for cables. Also had MFD2 as standard.
Still didnt work before i removed that diversity box.
Now both my antennas are active, and radio much better.
Reason I had to remove it is that the box switches between the antennas when MFD2 is installed, but in RNS510 this is built in the navi, and then the box will not switch, and then just one antenna is active.
This also depends how old your car is, and type of car.
Know people who have tried with antenna amplifier with no luck.
What car do you have, and what model?
http://vwnavi.com/showthread.php/11513-1-Fault-Found-00821-Antenna-2-for-Radio-(R93)?p=44485#poststop

And will be under passenger seat if you have it

doesnt really explain why the latest mods will have affected the reception unless AM was previously bad.

[JPC]

If the reverse camera isnt connected to the head unit then I would doubt that to be a problem, as it would be unable to affect the radio input.

It has its own power supply regardless of being connected to the headunit. I checked the earth point that i could find and that seemed fine. I dont know however if there is more than one earth.

I dont have any experience with the cd changer audio issue but that sounds to me like it would only affect the sound quality from the CD changer to the unit not the radio signal. 

I see what your saying but one of the pins that is swapped in this procedure is a ground.

So the error from VCDS looks to be your gremlim which ross tech give the following for
http://wiki.ross-tech.com/wiki/index.php/00821

so looks like a bad aeriel connection. (which we kinda already suspected)

Can I ask a couple of questions?  Firstly was there a nav in the car before fitting the MFD3?  What aerial do you have, shark fin, bee sting, or just rear window?

I had the RCD 300 (no nav before)
Ive got a shark fin aerial, but i have used this for 6 months. out of that, i have had 4 months solid reception!

ive since binned the old base so i cant use that! :( i kept hold of it for 3 months incase the signal from the shark fin got poor. but then binned it as the signal was fine.

And was the earth you used for the reversing camera used for earthing anything else? ie could it also be the earth for one or both of your aeriels?

unsure on that one!






Can i just ask about aerial inputs on the RNS 510. It has two inputs for aerial connections. FM/am i guess? that right? i have two leads in the car. One goes to the shark fin i guess, but where is the other?

[JPC]

oh and I dont think i have the diversity switch as that was scrapped in 2006 i think for switching in the headunits as you said.

My car is late 2008

[JPC]

just for info, i have found out i also have an antenna in the rear screen of my car.

really confused now!

[Gti Jal]

FWIW I had the old RCD300 and it was crap. I installed a Kenwood unit and its still crap!

[SteveP]

Jay the camera power cable run down the other side to the aerial, so I doubt that's the problem, but you can try disconnecting the fuse piggy back link to see if that makes any difference.

Have you tried swapping the aerial inputs around on the back of the RNS?

[JPC]

Yep tried swapping those. So the aerial runs down the passenger side? Never known where it is. I think I might put an amplified bee sting aerial behind the headliner. That still does explain the interference! I left the car in the unit tonight in bits ready for another assault tomorrow evening after detailing.

[mortygttdi]

Jay have you checked to see if there is any damage to the little brass pins inside the antenna plugs on the RNS? 

The antenna 2 is the deversity connection so there is a break on that...usually around the connection to the RNS so make sure all the connections are good? If you have vcds go onto the adv measuring blocks and watch the antenna 2 connection while your messing with the leads. Its live data so will switch between OK and short to ground on an open connection.

Good luck mate

Darren

[JPC]

brass pins checked.

thanks for the adv measuring blocks.

I had a look at that, and it showed antenna 2 having no signal whatso ever.

So, i was wondering if i had the wrong shark aerial. i think i have the phone aerial one. anyways, ive been to the breakers, got an old standard aerial base.

with the new base connected witth a whip aerial, the signal shot up.

Antenna 1 (rear window) strength was about = 75-80
antenna 2 (whip style aerial) dangling in boot = 90-95

I left the shark fin on the roof disconnected, i slimmed down the old aerial base and put it under the headlining with the whip screwed in. i also wrapped this is foam.

the signal then went down to 65-70. I have used it around town and my signal seems perfect.

I was thinking if it needed a boost i could install an amplifier, but looking in the aerial base, it looks as though there is already any amp in there??

there is plenty of circuitry etc? is that an amp in there?

[mortygttdi]

The shark fin that I have taken off the car had all sorts in it DAB, GPS, Radio and Phone that one was from the A4 I now have the later type shark fin/whip antenna and has radio on it but I've not connected it up.

I would say the radio antenna has the amp inside it for later cars.

Darren

[Richn83]

Glad its sorted now JPC, although very very odd that was working for 4 months and then went.

[JPC]

I know, I swore it was the engineers ficking around when doing the digital switch over!! Haha!

[Garth]

JPC, do you have the part number of the shark fin you have? If it's the same as mine (1K0 035 507 J), then it cannot be used as a radio antenna on our cars.
My RCD510 (not sure about RNS) has a diagnostics mode if you hold down the setup button. This shows the signal strength of both antennas and when I fitted the shark-fin, the menu told me ant1 was off.

I've done a fair amount of research on this now since my signal was initially pretty good with the shark-fin, but seemed to get worse after a couple of days. The best solution I can find if you want to keep the shark-fin is to buy the right hand amplifier and cable to connect the primary antenna to the rear screen as well as the secondary. The connection is already on the rear screen ready, so you only need the cables to connect it and the amp to power it. If you have ETKA, you can get the part numbers from there, if not, let me know and I'll dig them out.

 

[JamboV6]

This is what ive been meaning to do for months, after numerous people saying you have to keep the whip or have the dual sharkfin/whip! Just keep forgetting to order the amplifer everytime im at the dealers. Ive had the dummy sharkfin sat painted since last summer waiting to go on. just need to find the correct cable on etka or someone who can make them up. so many unfinished projects