Perhaps Too Far Away
As my old memory serves me the technique that might work is to plug in the spare "new" antenna, invert it over the old antenna-key way and then put your key in and try it..
I also understand that once you start it the antenna is NA...and can be unplugged and stowed..
Give it a shot...good luck!
2007 R1200GS Adventure " ...to explore off-road, alone in my case, way out in the boonies...that feeds the soul!"
After 2014 BOM my bike is forthwith the "GS McGee"!