Has anyone mentioned band-pass cavities? One on the RX side could be
enough and one more on the TX would do it for sure. There're some for
220 for less then a $100 on ebay right now. This might sound off the
wall but I once saw a DB4021 UHF band-pass cavity tune up quite well on
2 meters!!! Only about .6db insertion loss on 2 meters. So if you have a
VHF or UHF band-pass I would try sweeping it with the resonator in a few
different spots and see if you find any harmonics near your target
frequency. And I would only do this on the RX side. That UHF cavity
tuned to 2 meters did get warmer then the other db4001's, probably an
impedance issue. Forgot to mention the swr on that cavity was about 1.3
. So is this the worst practice ever, or what happened?
~Ross
-----Original Message-----
From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of Mackey
Sent: Monday, August 30, 2010 4:44 PM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Duplexers
Our club was recently given a 220 repeater. We have two seperate
antennas. We do not have a duplexer. My question is do we have to have a
duplexer? How can we keep the transmitter from desensitizing the
receiver? The antennas are apart but can be moved farther.
Thanks
Chris
Kg4bek
