dual radio antennas ??

can anyone tell me which lead is the radio antenna from the picture below please.



I would have assumed it was the larger one, but I what has confused me is that the smaller one is fits perfectly into my new PC radio jack.... whilst I have a convertor that would enable me to fit the larger one into the smaller one (if that makes sense) supplied with the new radio.

(New radio is HQCT-e, FM/AM usb which can be embedded into RR FE SW.)

Cheers
Tony

thanks Revtor, but.... which one would you choose if only going to use one ? Is there any way to combine the two into one via a connector, and feed both into the new unit ?

As plenty of people have swapped out their HU without complaint, I guess I shouldn't need to replace the diversity antenna, but time will tell.

thanks again, I'll go with the larger one first, but for completeness will see what is fed through the smaller one before securing everything back down and out of the way again.

Wont be doing it this week as I'm on holiday until monday after today. Got plenty of splicing and connecting to do with this new radio unit, as want to feed BT Phone speaker output into it. I also need to feed audio output from PC through it. Nothing is ever simple in the world of carpcs !!

is the antenna amplifer powered seperately ? In that it takes a feed from the ISO plug that would normally fit into the rear of the BMW head unit ?

I only ask as I cannot get a reception on any station, either FM or AM right now, and can only think that the the antenna must be powered seperately ??

I am only using the Large black connector, and not the diversity one.

I think this answers my question. I have no reception, and therefore figure that my antenna amp is left unpowered at present. Can anyone tell me which wire is the one that powers the unit, and where to find it (I really dont want to be dismantling the rear c pillar to trace it back if I can avoid it [SIZE=+1] )[/SIZE]

[SIZE=+1]Antenna system (from antennaworld.com)[/SIZE] All newer BMWs have the in-glass electronic systems by Fuba. The following information applies to these cars as follows: E31 - E32 - E34 - E36 and up

These cars have 2 or 3 antennas in the rear glass, including one which is the defroster wires, all embedded or printed on the inside of the glass. The usual configuration is a small computer/antenna selector/signal amplifier in the left side C-pillar. This small box can be accessed by removing rear seats completely then removing large plastic trim panel.


The "box" gets a signal from the radio via a thin (aprox 1/8") coaxial cable. This is an IF (Intermediate Frequency) signal out of the radio. My best guess is that it comes as a variable voltage level not a data signal. The computer uses this information from the radio to learn how strong the reception is at a given instant. As usual for a computer, antenna or antennas are selected at maybe 30 or 60 times per second. It is possible for the computer to select 1 single antenna or combine 2 and maybe 3.

If the original BMW radio is replaced with an aftermarket radio, the computer defaults to one antenna, probably the largest array. The reception quality will become fairly poor using a single antenna in the rear glass. The best solution apart from re-installing the original radio is to install a single antenna in the rear fender, the old fashioned, old reliable way. Otherwise an aftermarket radio with 2 antenna inputs (diversity system) would be a near remedy: In this case use the default antenna in the rear glass plus an aftermarket small electronic antenna inside the front glass.

Note: No reception on the AM band means the power is somehow disconnected from the antenna box in the C-pillar. Check for voltage at the box itself. Many times when installing an aftermarket radio the power lead to the antenna box is left disconnected. It should go to the power-antenna lead, (blue or green) of the aftermarket radio.

I looked and found that one labelled (WS = weis) and it makes more sense now.

This is the audio loom running backwards through the car from cabin. I assume that the wire held is the one to feed 12v+ .... ? it is white after all

Well that made no difference. 12v+ IGN feed into the white wire still produces no reception. Must be doing something wrong, but all connections on the radio unit are correct.

Is the Antenna grounded thruogh this loom ? Perhaps that's the problem as the loom is unused now since the stock system, amp and headunit have long since been removed ?

mine is a 1997 840ci Sport.

Come to think of it, I bet the white wire went into the amp and then out of it to the antenna ??? Then obviously the circuit is broken since the amp is on my shelf here.... !