If the transmiter is sometimes desensitizing the receiver,then re tune the or 
readjust the duplexeur.

--- On Tue, 8/31/10, cmcclel...@aol.com <cmcclel...@aol.com> wrote:


From: cmcclel...@aol.com <cmcclel...@aol.com>
Subject: Re: [Repeater-Builder] Duplexers
To: Repeater-Builder@yahoogroups.com
Date: Tuesday, August 31, 2010, 2:44 AM


  




Thank you for your response.
The problem is that the repeater is located on top of a building and the tower 
on that building is only about 20 feet tall. We can move the two antennas apart 
horizontally, but only 20 feet vertically.  Duplexers are way too expensive and 
hard to find for the 200 Mhz band.  We are running about 20 watts and the 
frequency separation is 1.6 mhz.  Sometimes a week signal comes in and 
sometimes the transceiver is desensitizing the receiver and covers it up.  Any 
suggestions?
Thanks
Chris
 

In a message dated 8/30/2010 8:36:53 P.M. Eastern Daylight Time, 
wb6...@verizon.net writes:
  

Chris,

You do not have to use a duplexer, but it makes building a repeater SO much
easier! Keep in mind that "antenna separation" usually means vertical
separation, not horizontal separation. Moreover, the same isolation
provided by 1000 feet of horizontal separation might be provided by 10 feet
of vertical separation. The amount of isolation you need is based generally
on the transmit power, frequency separation between TX and RX, and the
sensitivity of the receiver. The receiver bandwidth and antenna types also
play a factor.

73, Eric Lemmon WB6FLY


-----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










      

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