How long do I cut the limbs for PMR 446?

[NorthernRaider]

Cool, Ampifier duly forgotten about,
I will shorten coax as suggested.
The Delboy Dipole is made exactly as described with exactly 160mm limbs into choccy block connector with the coax soldered directly to the limbs/ choccy block. so there is only the one connector adaptor at tother end to connect the coax to the UV5RC, thats the PL259 -SMA male bit, is there a more efficient connector?
Wassa N type connector will it fit to SMA female on the radio??

I'll try and get dipole shifted from loft to outside corner where it will fasten to eaves.