At 2/16/2007 05:35, you wrote: >" Wouldn't the pitting give the antenna more surface area, broader >bandwidth, >and more gain? DE NU5D" > >The pitting actually seriously impacts antenna performance as it causes >ERP to drop off. What happens is instead of efficient conversion from >conducted to radiated energy, you get significant losses from heat.This
IIRC Aluminum Oxide is a low-loss dielectric. Unless it forms with significant impurities on the antenna, I don't see where the loss would come from. >is why almost every 'extreme-duty' antenna manufacturer are now offering >hard anodizing options for their mountaintop antenna products. The only >way you can test for this is to do repeated far-field strength >measurements over time. The antenna itself will test fine; return loss, >VSWR, all look great, but it just doesn't talk as far. ...or pump a LOT of power into it & use a non-contact IR thermometer to look for surface heating. Bob NO6B
