XSeries-forum

Hi guys

Some of you may remember me; I was the bimbo who thought an M5 is the same as an X5 LOL  )

Anyway, I'm a girl who likes to get my hands dirty ('suits you sir!' etc banter), so I had a Saturday project of installing an ariel amplifier to my snap in adapter, as I am on Vodafone and the signal is s***



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... - See instructions: http://speedy.sh/d7wtw/Scan-57.pdf - click on 'slow download' (I can't seem to attach anything to this forum post? Help please!) and then continue reading...

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;



...and unplugged them...



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



I then changed pins etc. as per page 8 of instructions. A tiny screwdriver came in very handy here to take pins out!



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 to not bend the coaxials at too sharp a angle as this damages signal (very similar to the cables behind a Sky digital/sky+/sky+ HD/etc. box, but thiner)



In the end I gave up on trying to do it neatly, but made sure that the coaxial cables weren't bending too much and then shoved it all in. X29*1 was now a lot bigger and didn't clip into the side wall in the same way it did originally, therefore I just pushed it into that sort of area- It only just all fit in.

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)

Obviously, being a bimbo, I didn't do the logical thing and measure signal strength before adding the amplifier so I could compare like-for-like.

This was measured in a notoriously bad signal area, otherwise known as Balsall Common in the West Midlands.

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

xxx

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)


xxx

For those wondering about dBm it's a logarithmic scale radio engineers use to keep numbers small (which we like) rather than large (which we don't).

A change of +/-1dBm is 1/10th.  +/-3dBm either doubles or halves.  +/-10dBm is a factor of 100 either way.

-83dBm is +23dBm, and therefore much better than -106dBm.  We are of course still working in microvolts (millionths of a volt) so the signal level is tiny.