MikeN wrote in message . ..
Hi all.

I've got a 70 cm Yagi which is to be matched to a 50ohm feedline,
feeding a 70cm repeater (5MHz split).

The Yagi has an impedance of 12.7+j0.8 (so 4NEC2 tells me).

....

I've simply used a folded-dipole (equal diameters for the two
sections) driven element in similar cases. That should give you very
close to 50 ohms. It's balanced, so use a 1:1 balun to get to 50 ohm
coaxial.

Cheers,
Tom