Freeview Fitted to E39

[Crazy Dave 0]

I fitted one of these units to my E39 touring a couple of days ago. It works really well. I'm using the supplied antennas at the moment until I can get the correct connectors ..............................

So I got the connectors and am experimenting with the cars in built antennas on the DVB-T tuner. At first it did not work at all. I checked the DC voltages to drive the antenna pre-amps. The DVB-T tuner supplies 5 VDC to the coax and can be switched on and off from the menu. The OEM analog tuner supplies around 10VDC and so I thought that this was the problem.

However after a bit more playing it seems that the in built glass antennas do work, but they are just not as efficient as the stick on supplied ones.

I also found that if I connect one antenna it works far better than having both connected. I am still trying to get my head around that !!!

I will keep playing until I find the best solution.

[hotwire 352]

So I got the connectors and am experimenting with the cars in built antennas on the DVB-T tuner. At first it did not work at all. I checked the DC voltages to drive the antenna pre-amps. The DVB-T tuner supplies 5 VDC to the coax and can be switched on and off from the menu. The OEM analog tuner supplies around 10VDC and so I thought that this was the problem.

However after a bit more playing it seems that the in built glass antennas do work, but they are just not as efficient as the stick on supplied ones.

I also found that if I connect one antenna it works far better than having both connected. I am still trying to get my head around that !!!

I will keep playing until I find the best solution.

Interestimg Dave - I would have thought it to be a no go to try to use factory analogue antennas to operate the DVB-T tuner.

[Crazy Dave 0]

Interestimg Dave - I would have thought it to be a no go to try to use factory analogue antennas to operate the DVB-T tuner.

The digital TV transmission is in the same frequencies as Analog UHF TV. And it is just a radio signal so the antennas can be the same. All the BS around needing a new "digital" TV antenna to receive digital signals in your house is just marketing to sell some antennas riding on the back of a technology change.

Things only change when the RF is demodulated down to baseband signal inside the receiver.

My problem is that I am unsure about the circuitry in the BMW pre-amps in the pillars. I am wondering if they are giving less gain at the 5VDC supplied by the DVB-T receiver. I might build a splitter circuit to feed both the Analog and DVB-T receiver while only supplying the DC from the Analog (OEM) receiver.

[Crazy Dave 0]

Interestimg Dave - I would have thought it to be a no go to try to use factory analogue antennas to operate the DVB-T tuner.

Well, I am now a bit confused. After playing with DC blockers, the DC feed to the OEM antennas does not seem to matter between 5VDC and 12VDC. The antennas work just as well at either voltage.

What I did discover is that if you connect both built in OEM antennas to an aftermarket DVB-T tuner then it goes really deaf. It has to be a really strong signal before you get a TV picture. (15km from the Christchurch transmitter)

If I connect one built in OEM antenna to the aftermarket DVB-T tuner then it is almost as good as the two supplied (ugly) antennas stuck to the windows. (40km from the Christchurch transmitter)

So at the moment I have one built in OEM antenna to the aftermarket DVB-T tuner and one OEM antenna to the old Analog OEM tuner and the system is working pretty well. (and no ugly stick on antennas)

I suspect some sort of earth loop or diversity switching signal supplied separately to the antenna pre amps may be the issue but I have always struggled with the WDS site so need to get my head around the wiring to those preamps.