WRWI497

I bought one of these about 9 months ago to use with my repeater built from 2 Wouxun KG-1000G 50W radios and a Fumei mobile 50W notch duplexer. I initially used it to replace a TRAM 1486-B with 6.5dBd gain; the Comet has 6.85dBd gain. The installation was at 45 feet above ground and the results were marginally better. I could only get around 5 miles range with either antenna. I live a swamp in southeastern Louisiana so there are many 80+ foot trees over flat ground. I used an EZ-Hang slingshot to place a rope 75 feet above ground. Didn't get much of an improvement in range and I had to use 126 feet of KMR-400 coax. I measured 62% insertion loss through the coax. I bought a professional spectrum analyzer and tuned a used Phelps-Dodge 6 cavity BP/BR duplexer I found on eBay. I detected another slight improvement. What seemed give me a more solid range was inserting a NooElec ultra low noise amplifier between the receiving radio and the duplexer. Suddenly, I had a fairly solid range at 7.5 miles radius, and 19 miles while driving on top of overpasses. i conducted range testing with a 20W (that transmits 16W) Btech 20V mobile radio. I also used a Surecom simplex repeater with an HT to parrot the full duplex repeaters output because I was testing by myself while driving around. Anyway, after 2 weeks of excellent repeater coverage, a rainstorm cause the two halves of the Comet CA-712EFC radome to separate. The top half of the radome is now permanently 75 feet up in the tree! Realize that I have a rope tied to the top of the antennas that hang off a branch. I replaced the Comet antenna with the TRAM again. Under the same conditions, the range is about the same, but not with solid coverage. I will probably buy another Comet CA-712EFC and pull it up the same tree, but before I do so I will epoxy the two halves of the radome together. The compression connection between radome halves isn't designed or strong enough to mount the antenna from the top with all that coax hanging below. I do recommend this antenna. It works well, but I wish there was a way to tune it. It is made with a collinear coax design. Mine came center tuned at 465mHz, but the VSWR on the input frequency of 467.55mHz was about 1.5:1 VSWR and higher than the output frequency of 462.55mHz at 1.3:1 VSWR. I would prefer better tuning on the input because if the repeater is deaf, it will also be mute.