I can't figure out how those hands-free kits get the external antenna signal into the phone.

Specifically a Motorola MicroTAC 650 phone (el-cheapo), has 8 pins on its option connector.
J3 Pin Function
1 Logic Ground
2 Ext. 7.5V
3 TRU
4 CMP
5 RTN
6 Audio Ground
7 RX Audio OUT (spkr)
8 TX Audio IN (mic)

Pins 3,4,5 are data bus lines. So how does the antenna work in this scheme? I have seen the hands free kits, most have a provision for a glass mount antenna and coupler. (Looks like bnc coax connector, from what thumbnails I've seen on the net)

The faq's have shown me what is available in the 25pin dshell in the A4's trunk. And now I know what's available from the option connector on my phone. I'd like to avoid buying a hands free kit and just make all the connections myself.

But what's up with the external antenna? Is it somehow carried on the power pins?

Thanks for any help.
I'm also positng this on alt.cellular.motorola

slack
99.5 2.8M

This little plug fits into connecter on hands free cradle which has coax cable to antenna. 8 connection pins not for antenna. Ross