Finally finished my homebrew 5-element VHF yagi after weeks of mechanical work, but I'm struggling with SWR tuning. Getting about 1.6:1 at 146 MHz but it jumps to 2.3:1 at the band edges - much wider than expected. I've tried adding small tubing sections to the driven element tips as suggested in various articles, but the adjustments seem too sensitive. Using a half-folded driven element design with 50-ohm direct feed per WA5VJB specs. Should I add a short coax jumper to verify my SWR readings aren't being affected by feedline resonance effects?

Make sure your coax drops down in a wide loop away from the boom - odd multiples of 1/4 lambda can definitely mess with your SWR readings. Try ferrite cores on the feedline first - I've seen SWR drop from 1.15 to 1.08 on 2m just from adding one Grade 31 ferrite.

Don't start cutting anything yet - those dimensions will change! What modeling software did you use for the initial design? 4NEC2 optimization can give different results, but if done correctly there shouldn't be major issues.

Try rocking back and forth between tip length adjustments and your matching method to find that perfect 1:1. This isn't as hard as it sounds but is crucial to master if you're building yagis from scratch - nothing beats rolling your own. What's your driven element total length right now?