Here's my way!

https://nandustips.blogspot.com/2011/02/coupling-commercial-vhf-hand-held-to.html

Regards,

Nandu.

 

Hello,

The handheld you show has a BNC connector, just as mine FT209, that has a ground connection.

Why not use a BNC as coupling?

Bertus

 

All my newer handheld radios have SMA connectors. SMA-BNC or SMA-UHF adapters are readily available...

 

there should be a headset / microphone connector on that radio, if so, there is an antenna connector built in the speaker mic.