Good Evening;
I just installed a repeater at a new site, and am a little disappointed in the performance. Plots using Radiosoft, which has been damn close to predicting the coverage on my other repeaters, led me to expect more performance than I am seeing from this site. I have been waiting for RFS to deliver a 440-450 PD455, which has been delayed yet again. So while the tower guys were doing their thing, I threw up a PD1151 cut for 450-460. The site seems to cover a wide area, but the signal is never strong, even close in. The transmitter is on 440.xxx. I have used one of these PD1151 450-460 antennas in the past on a 449.xxx repeater, and it plays quite well. Is it possible that while the 449 system is close enough to the design range of 450-460, the 440 system is experiencing the effects of being too far from the design frequency range? THe SWR, while not perfect, is about 1.5:1 at 440MHz. Does the radiation pattern start to distort that severely when almost 10MHz from the design/cut frequency of an antenna? I know a lot of you are using DB420's down in the 440 band with good results. Are the dipoles that much more broadband, and less suceptible to radiation pattern distortion than the co-linear type antennas? As an experiment, I'm tempted to stick a spare 449.xxx box on the antenna over the weekend to see if it plays any better than the 440.xxx box to confirm or deny this suspicion. Hopefully, I'll receive the ham cut PD455 sooner than later. Eric KE2D
