Aerial connections

[mikefrew]

Hi all, I fitted one of the chinese dd units about 6 months ago and have now decided to try again to get a decent signal to radio and tv. My question is, can I connect dd straight to the amplifiers in pillars, and if so which wires would I connect to? I originally had a hi-line fitted. If I have to go from the boot, which wire do I use from the tv unit? the radio one is self explainatory.
Thanks,
Mike

[HarryM1BYT]

Originally Posted by mikefrew

Hi all, I fitted one of the chinese dd units about 6 months ago and have now decided to try again to get a decent signal to radio and tv. My question is, can I connect dd straight to the amplifiers in pillars, and if so which wires would I connect to? I originally had a hi-line fitted. If I have to go from the boot, which wire do I use from the tv unit? the radio one is self explainatory.
Thanks,
Mike

I'm not absolutely clear what you are asking, nor which TV type you are trying to connect, however...

In the wheel well there should still be the two TV coax cables fitted with a SMB type plug. If your TV needs a single antenna feed, you could use either one of these. I fitted my new TV unit in the boot and it needed both antenna feeds to be connected. This thread will give you some clues about changing the SMB plug to an F-plug, which is a standard for TV/ Satelite coax. -

http://www.the75andztclub.co.uk/foru...ad.php?t=77251

I would also suspect that like me, swapping the Hi-line for DD, will have cut the permanent 12v (purple/pink) and the switched 12v (purple/ yellow) feeds into the boot area. These are needed to be working, to feed the antenna amps. They need to be reconnected in the dash, behind the DD. See my thread about getting the HK amp working for more details on these wires.

The Radio antenna coax terminates near the TV ones and Sean supplied an adaptor in the kit, so all you need is a 6m long entension to get that to the DD. Be warned that some of the early cars used a fancy radio antenna amp, using two antennas, with the radio module selecting which antenna was working best at any instant and enabling the best one. The DD lacks this facility to provide the feedback to the amp, so it may not work very well.

[mikefrew]

Thanks for the reply Harry, should have been a bit clearer. The unit I have is not one of Sean's, but a cheaper chinese model.
I have built in analogue on the dd. I knew about the 2 SMB plugs on the tv tuner, but did not know which one to use, now I know I can use either.
My other question was can I connect straight to the amplifier in the rear pillar or do I have to go from the tuner in the spare wheel well?
I have not cut any wires in the boot, just connected a 17 pin bmw to iso converter behind the unit, does this mean the power wires for the amps will still work?
Thanks,
Mike

[HarryM1BYT]

Originally Posted by mikefrew

Thanks for the reply Harry, should have been a bit clearer. The unit I have is not one of Sean's, but a cheaper chinese model.
I have built in analogue on the dd. I knew about the 2 SMB plugs on the tv tuner, but did not know which one to use, now I know I can use either.
My other question was can I connect straight to the amplifier in the rear pillar or do I have to go from the tuner in the spare wheel well?
I have not cut any wires in the boot, just connected a 17 pin bmw to iso converter behind the unit, does this mean the power wires for the amps will still work?
Thanks,
Mike

You don't need to physically cut the wires to lose the supplies to the boot, just removing my Hi-line units were enough. Best advice would be to check with a meter, that the purple/pink and purple/yellow are live with the ignition turned on and if not, to link them across at the back of the DD.

I can't help at all with the type of plug used at the TV amp, because I have never seen it. In your situation, I would be inclined to simply run a length of CT-100 modern Sat/TV cable from the DD to the wheel well, fit an F-plug at the boot end, use an F-plug female to female adaptor, then fit one of those special Shotgun F-plugs on the end of one of the two leads presently fitted with an SMB.

[Duotone]

This picture shows the aerial amp located in the rear nearside D pillar.

This is for Hi Line sat nav installations.

The aerial out plug is the connector marked in yellow.

You could connect a piece of aerial wire to the amp and then direct to behind the dash.

Running a cable from the D pillar to the dash is as easy as running a cable from the boot.



Dave T

[HarryM1BYT]

That picture seems to be that of the radio antenna amp, of the earlier diversity type system. The plug in the red circle is the feedback system from the radio receiver, to tell the amp which of the two antennas provides the best reception.

The later system just makes do with a single antenna and therefore no need for any feedback to the amp to switch antennas.

What Mikefrew was looking for was details of the twin antenna amp for the Hi-Line TV, or the type of plug needed.

[Duotone]

Originally Posted by HarryM1BYT

That picture seems to be that of the radio antenna amp, of the earlier diversity type system. The plug in the red circle is the feedback system from the radio receiver, to tell the amp which of the two antennas provides the best reception.

The later system just makes do with a single antenna and therefore no need for any feedback to the amp to switch antennas.

What Mikefrew was looking for was details of the twin antenna amp for the Hi-Line TV, or the type of plug needed.

The OP was trying to improve the radio signal.

The picture showed the diversity amp, this amp works very well without the feedback from the headunit.
The feed from the headunit is to enable the "speed related volume control" to operate and only applies to the Symphony headunit.

This picture shows the TV aerial amp and the connectors but it has nothing to do with the strenth of the radio signal.



Dave T

[HarryM1BYT]

Thanks Dave - I don't recognise the plug type from that photo though.

- and thanks for confirming that the diversity type of radio antenna does still work well without the feedback.

Not having one of this type fitted, I wasn't sure how it might behave without the feedback. Several DD installers have reported extremely poor reception, but it hasn't been clear whether it might be due to the diversity antenna system or some other problem.

[Duotone]

Originally Posted by HarryM1BYT

Thanks Dave - I don't recognise the plug type from that photo though.

- and thanks for confirming that the diversity type of radio antenna does still work well without the feedback.

Not having one of this type fitted, I wasn't sure how it might behave without the feedback. Several DD installers have reported extremely poor reception, but it hasn't been clear whether it might be due to the diversity antenna system or some other problem.

The plugs connected to the TV amp are BNC connectors.

On the HI Line system, if you connect the radio aerial to the boot area radio module then you are taking the radio sigal from the rear screen via the diversity amp to the boot then to the head unit, its a round about route.

The radio aerial cable should be as short and without extra connectors as possible.

This the other type of aerial amp..



Dave T

[HarryM1BYT]

Originally Posted by Duotone

The plugs connected to the TV amp are BNC connectors.

BNC, easier to get hold of and a bit easier to fit.

On the HI Line system, if you connect the radio aerial to the boot area radio module then you are taking the radio sigal from the rear screen via the diversity amp to the boot then to the head unit, its a round about route.

Agreed but the plug into the none diversity antenna amp looks as if it is a special, not like anything I have ever seen before. So my options were to find an adaptor (very unlikely) or attempt to change the socket on the amp PCB to a standard car radio plug. I might get around to having a go at doing the latter method eventually.

The radio aerial cable should be as short and without extra connectors as possible.

Agreed and the same with any RF connectors, which was why I mounted my DVB-T in the boot.

This the other type of aerial amp..

and the one mine has fitted.



Dave T

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