RE: [Repeater-Builder] Help with Wacom WP-639 Duplexer

[Rob Martin]

All   Today I have spent a couple of hours sweeping the cavities and come to the conclusion that they are all high pass low reject. (Originally of tx152 & rx158) Looking at the cavities  25mhz either side of my desired frequency RX145.1625Mhz TX 145.7625Mhz I can a second notch but this never comes within 2Mhz of the pass with the invar rod all the way in. They tune perfectly for pass high notch low.   So it looks like I have a set of useless cavities unless anyone knows what the physical difference is between the High Pass Low Reject and High Reject Low Pass. Can I make any modifications?   Bob G6CKK   -----Original Message----- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Kevin Custer Sent: 03 June 2005 12:51 To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Help with Wacom WP-639 Duplexer   m1ror wrote: Hello All   This is my second posting but I'm not sure if my first attempt made it to the list.   I bought a set of what appear to be good condition Wacom WP-639 (144- 174Mhz) Duplexers originally tuned for 156Mhz. A friend has attempted to align the filters but is having problem aligning the notch down to 145Mhz. The problem he tells me is he can only get the notch down to 148Mhz with the Invar rods pushed all the way in. He has made up new patching loom and still the same result. Has any body played with these and could offer any advice? Have him swap the ports and try again, in other words, tune the duplexer backwards from the way it is presently tuned using the opposite sides for the receiver and transmitter.  Minimum frequency separation happens with the rods all the way in, which leads me to believe he is attempting to tune the duplexer upside down, on the 'wrong' notch; there are two notches, as explained below.... This article explains the basic principal for the Wacom WP-641 and 639 style pass notch network.  While specifically written about the 641, the effects are the same for the 639, however, the notch depth won't be as deep with the 639 as what is stated in the article: <http://www.repeater-builder.com/wacom/wacombpbrnotes.html> Complete tuning directions are available from this page: <http://www.repeater-builder.com/wacom/wp6xxVHFtuninginstructions.pdf> If you still encounter difficulty after attempting the switch-a-roo, email us back.... Kevin 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.