# BMW Snap-In Adapter Antenna Amplifier



## sunnydude959 (May 20, 2006)

Hi Guys

I wonder if anyone on here has fitted the Snap-in Adapter Antenna Amplifier to their car?

I've just ordered one, and received the installation instructions (attached) and it seems quite involved. For example, how would I attach cables A3 and A4 to pins 5 and 2 respectively, ? Is it something that requires soldering?

Thanks

Sunny


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## sunnydude959 (May 20, 2006)

I must have been overthinking it at first! Its a lot simpler than I was making it out to be...

A: To steal power from the snap-in adapter's charging power supply, by adding the amplifier in parallel to it
B: From amplifier to the roof
C: From amplifier to the snap in adapter

A2 + E: Power in
A3/A4: Power out back to the snap in adapter


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## tim330i (Dec 18, 2001)

Let us know if you notice a difference.

Tim


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## sunnydude959 (May 20, 2006)

Right then, I received the package;










It _looks_ fairly user friendly and plug and play to start with at least. He's still smiling in the photo so couldn't have been too bad, surely? Well...

I started by pulling the base plate out of its recess using two trim removal tools, prying it out gradually. I then disconnected the 18 pin connector (X29*1);



















I then found the USB and antenna cables clipped onto the side of the cavity;










Disconnect these;










I then took the base plate inside my house for rewiring. Here it is to start with...










Then following page 8 of the instructions, pins are changed;










The connector is put back together again and tidied up...










This is probably the hardest bit, especially on an M5 (as the centre console seems to be smaller) - putting it all back in!










*I had to be very careful not to bend the coaxial cables too much!*

*(Use the above information at your own risk. I accept no responsibility for any damage as a result of attempting the steps above)*

As far as results go... Well. I don't know how much better it is compared to just the snap in adapter on its own (I wish the amplifier could be temporarily switched off so i could compare), but I have the following results between SIA+Amp and non-SIA:

2G: -93 Db (cabin), -78 Db (SIA+Amp)
3G: -113 Db (cabin), -97 Db (SIA+Amp)

This was measured in a notoriously bad signal area.


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## sunnydude959 (May 20, 2006)

Ok, I managed to disable the amplifier by pulling the SIA fuse out (note: if you have Bang & Olufsen, this fuse is shared with the centre speaker going up and down) - Fuse #27 on F10 cars. I now have a full comparison on 3G;

Physically placing iPhone on roof: -96 Dbm
Cabin: -106 Dbm
SIA without amp: -97 Dbm
SIA with amp: -83 Dbm

(If anyone is wondering how I got signal in Dbm values, then wonder no more: on a modern iPhone, dial *3001#12345#* and press call. A new window will pop up. Then, hold down the power button until the red slider appears, and then press and hold the HOME button until the phone goes back to its normal standby screen. Signal should now be displayed in numerical form. If you want to go back to bars (or blobs) then swipe right over the area where signal is displayed. You can then go back to Dbm values by swiping right over the same area again, as its essentially a toggle switch.)

(Again, Use the above information at your own risk. I accept no responsibility for any damage as a result of attempting the steps above)


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