I use 2 of these, try adding an additional pass cavity on the RX side.it improves the performance greatly. Also, check the duplexer with an return loss bridge and a tracking generator. The slightest off-tune of the unit, especially the rejects and you get noise.I assume that you are suing double shielded cables, like rg142, and NO coaxial adaptors in line. Additionally, make sure that your transmission line is NOT the LMR stuff... very bad for duplex situations. Lance ----- Original Message ----- From: Tony L. To: Repeater-Builder@yahoogroups.com Sent: Wednesday, November 07, 2007 11:10 PM Subject: [Repeater-Builder] 2 Meter Duplexer Recommendations?
My Celwave PD 497-1-1 VHF duplexer just can't seem to provide adequate tx/rx isolation (Micor 100 watt repeater with 0.6 MHz tx/rx separation). Everything else seems to check out okay; jumper cables, connectors, receiver, and hard line. I've heard the PD 497-1-1 isn't the latest in duplexer design and was wondering what other VHF repeater owners might recommend with regard to high performing, closed spaced duplexers for moderate power applications. Thanks.
