Re: [Repeater-Builder] WACOM WP-641 Duplexer

[James]

Bob Dengler wrote: At 10/15/2004 09:19 AM, you wrote: Duplexer companies that use RG8, 58, 213, or any of that noisy crap should be "burned at the stake" :) ...including Phelps-Dodge? I don't think so. The only problem with the coaxes you mention is that the braid is not solid or silver-plated. If any water gets inside the coax in any way, the copper braid eventually oxidizes & generates IMD. The noise you get is probably mixing between the TX carrier & its sidebands, which you induce when you move the coax with it's millions of point-contact diodes. If the duplexer is kept in a controlled environment (not outside), the cables shoudn't degrade. I had a piece of RG-8/X used as a pigtail to a portable repeater antenna that looked perfectly good on the outside, but generated noise such as you describe. Cutting it open revealed the water infiltration. In fact, it only generated noise when flexed in the area where water got in. Further down the coax where the braid still appeared shiny there was no noise when flexed. I replaced the pigtail with RG-142 & that solved the problem. The fact that RG-142 is double-shielded is incidental; it's the silver plated shield that prevents IMD generation. And may I add,  the BETTER isolation from other "artifacts" coming in through the shield!!  Nothing less than high quality coax for those of us that don't have perfect sites that are climate controlled and noise free. James Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/   To unsubscribe from this group, send an email to: [EMAIL PROTECTED]   Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.