Bob,
Thanks. I have someone with good equipment coming Sunday to check it out and re-tune as needed. I'll let you know what we found. Re the de-sense, there are two other antennas close by but both are for much higher frequencies. The three feed lines all go down the same conduit. We are using 7/8 Heliax and I believe the others are smaller Heliax or hard line. I plan to replace the cables in the cabinet when new cables (now ordered) are ready. John -----Original Message----- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Saturday, July 05, 2008 1:59 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Cables on Duplexer John: I'm not seeing your reply text. Please turn off all text formatting in your e-mail client & resend as plain text. Thanks. Bob NO6B At 7/5/2008 06:32, you wrote: >-----Original Message----- >From: Repeater-Builder@ <mailto:Repeater-Builder%40yahoogroups.com> yahoogroups.com >[mailto:Repeater-Builder@ <mailto:Repeater-Builder%40yahoogroups.com> yahoogroups.com] On Behalf Of [EMAIL PROTECTED] <mailto:no6b%40no6b.com> >Sent: Thursday, July 03, 2008 12:36 AM >To: Repeater-Builder@ <mailto:Repeater-Builder%40yahoogroups.com> yahoogroups.com >Subject: Re: [Repeater-Builder] Cables on Duplexer > >At 7/2/2008 13:07, you wrote: > > >Hi John, > > > >I want to suggest that you check the preamp, make sure it didn't get hit > >by lightning, or overloaded, also (if possible check you cables, I have > >had some change things happened that appears that the receiver is to blame > >but not in all cases) Then check the receiver to make sure it still has > >its sensitivity 0.25 - 0.35uv, or better should be good. I will hate to > >touch the duplexer without making sure that these other components are > >checked. > > > >Hope you get fix, let us know what you find, when you do. > > > >v44kai.....Joel. > >>----- Original Message ----- > >>From: <mailto:[EMAIL PROTECTED] <mailto:jtransue%40cox.net> net>John Transue > >>To: > >><mailto:Repeater-Builder@ <mailto:Repeater-Builder%40yahoogroups.com> yahoogroups.com><mailto:Repeater-Builder%40yaho > ogroups.com>Repeater-Builder@ <mailto:Repeater-Builder%40yahoogroups.com> yahoogroups.com > >>Sent: Wednesday, July 02, 2008 12:38 PM > >>Subject: RE: [Repeater-Builder] Cables on Duplexer > >> > >>Bob, > >> > >> > >> > >>I don't have a way to measure this accurately on the receive side, but > >>just using a signal generator and my ear, there appears to be about a 2 > >>dB loss in the duplexer. > >OK, now I see your reply. Don't know why this text wasn't there on your >original reply. > >2 dB is rather high for a UHF duplexer. However, you've only moved the >duplexer less than 2% of it's original frequency, so I doubt that any of >the cables would need to be replaced as a result of the frequency change. > >You're also experiencing a bit of desense as well. Might be worth >rechecking the duplexer tuning & loss on good test equipment (spectrum >analyzer with tracking gen. or better yet a VNA if you can get access to >one). However, there are many other possible causes of desense. The most >common I run into are mixes caused by bad hardware in the near field of the >antenna (other bad antennas, feedline, loose tower joints, etc.). > >Bob NO6B __________ NOD32 3192 (20080616) Information __________ This message was checked by NOD32 antivirus system. http://www.eset.com
