What's an Antenna regulator and do I need it?

[Utter chaos]

Hi All,


I have a 2006 X5 and am lucky enough to have an antenna regulator (6945425) connected to the Bluetooth.


Well.... I say connected, I actually broke the Fakra connection when changing out the TCU.


Question is,... what does it actually do and do I need to get a new lead (£25±) to connect it?


Here's one on eBay if you've never seen one before:

http://bit.ly/1qT4s0T


.....the bloke selling it doesn't know what it does either!

Cheers