In a message dated 7/27/2007 11:16:58 A.M. Pacific Daylight Time, [EMAIL PROTECTED] writes:
According to Lloyd, the cable length between a duplexer and an inline cavity filter and the receiver makes little or no difference. This simply doesn't square with the advice Lloyd gave me during the eighties. For example, he personally set up three sets of VHF systems for me. Two of them were specials, i.e., the standard WP-642 duplexer plus an additional 8 inch pure pass cavity on each side - a total of six bottles. Lloyd supplied all of the interconnects between the duplexer cans and also supplied the cables between the duplexer and the pass cavities. To minimize possible cable interaction I told Lloyd that I wanted to change the cable length between the duplexer and the pass cavities. He said, no, he wouldn't recommend that and that the cable was selected to provide optimum phasing of the duplexer and pass cavitity curves. And when I tried substituting a different cable length, the tracker indeed did show a different composite curve. I subsequently had Lloyd set up two UHF specials - the standard WP-678 plus WP-478 pure pass cans. Lloyd specified the cable length between the duplexer and the pass cavity as 9 1/2" for the low pass and 9 1/4" for the high pass (not including N connectors. When I told him that there was no way I could physically arrange the cans using this cable length, he said, no problem, he would use a multiple and the cables that came with the pass cavities were 20 1/4" for the low pass and 20" for the high pass (including connectors). Now, if the cable length between the duplexer and the pass cavity was of little or no difference, why would Lloyd would have suggested and provided a half wave multiple length? Why wouldn't he have said "use any length that works for you"? Bruce K7IJ ************************************** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour
