[TowerTalk] Understanding the 75Ω half wave balun on a T-Match

[Jay Kesterson K0GU]

Need to better understand the 75 ohm half wave coax balun on the T-Match 
of a yagi. I have a number of M2 V/UHF antennas, from 50 MHz to 432 MHz, 
that use RG-6 for the balun. Since RG-6 has a tiny fraction of the power 
rating required for a feed line at the UHF freqs I obviously don't 
understand how the balun operates. How broad band are these baluns?

After 10 years in the air I recently took down my box of M2 6M7JHV yagis 
for a stacking design change. I decided to replace the baluns and will 
make my own. One of the old baluns was 6% short according to formula 
using the manufacturer's velocity factor spec. Not sure how much 
difference that makes in a stacked array?

Info appreciated,

73,  Jay  K0GU