Dave, You're probably right that the new location probably makes up for a lot.
Have you been able to confirm that the antenna still works up at it's rated freqs? How much feedline loss are you dealing with? Most 'good' sites have significant feed line runs and therefore loss. While I haven't spotted where you indicated this, it sounds like a tower site. Feedline loss improves your apparent match by twice the loss of the feedline. 2:1 is 9.5 db return loss. If you have 3 dB of feedline loss, that's a 6 dB improvement and the RL at the antenna is 3.5 dB (~5:1) this might expalin why you can't stub tune it out. One of your earlier posts indicates that this is a PD-220-3A. This is a collinear with a beamwidth of 18 degrees. It's low enough gain where the beam tilt out of band isn't likely to be a factor. The up (or down) tilt of a collinear is dependent on frequency. At UHF and 800 with high gain antennas this can be a real factor. You can get great match but put all of your energy into the ground (or into space.) It's also a reason that a lot of antennas don't work well upside down. This is a real problem with high gain collinear wireless LAN antennas. N1OZ -- mailto:o...@ozindfw.net Oz POB 93167 Southlake, TX 76092 (Near DFW Airport)
