You need to have a service monitor that has a tracking generator / spectrum analyzer to accurately tune the duplexer. Find someone that has one help you with tuning the duplexer. If nobody has one, take it to a radio shop and ask if they could please re tune it. They may or not charge you.
Mike K7PFJ From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of hbbcara Sent: Saturday, July 18, 2009 6:48 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] wp-639 -- How far should I expect to move the invar rods? Hi all, In tuning the reject for a wp-639, how far should I expect to move the invar rods to find the notch? In tuning mine (the poor man's way - system on the air receiving a weak station) I didn't find a definite place I"d call a null. There was more noise on the signal with the rod pushed most of the way in and less noise with the rod most of the way out, but it was a gradual change. I expected to find it noisy with the rod mostly in, noisy with the rod mostly out and at some point in between a quieter spot. SO my question is, should I hear a definite "noisey-quiet-noisey" pattern as I move the rods and if so, over how much motion of the rods is it likely to fall? An inch? Half-inch? Three inches? Or would that pattern only be noticeable with "the right equipment." (Some background - the duplexer is from an uncertain origin, but it has a factory sticker saying 146.97 - 146.37 with the ports marked "high input" and "low input." I'm using it on 146.88/28 so it shouldn't be an "upside-down" issue.) Thanks for any info! rj Checked by AVG - www.avg.com Version: 8.5.375 / Virus Database: 270.13.15/2239 - Release Date: 07/15/09 06:07:00
