So from what I am getting here. Only some PA's are affected by the cable length. Mine happens to be a Master II Tband. It's only trial and error to discover it the problem. It's trial and error to make the cable length right so the PA is happy.
If I understand this right, what cause the problem is the PA's output is not a true 50 ohms by failure or design. This causes the 50 ohm coax to not be matched to transfer the power from the PA to the duplexer. So you alter the cable length to make it match the output of the PA impedance. Which in turn helps it to transfer the power to the duplexer. Why does this work? Isn't the input to the duplexer also 50 ohms? Too much thinking for a Saturday morning! -Tim > -----Original Message----- > From: Joe [mailto:[EMAIL PROTECTED] > Sent: Saturday, October 02, 2004 4:45 AM > To: Repeater-Builder@yahoogroups.com > Subject: Re: [Repeater-Builder] Duplexer story update > > > I have used a short cable, then used various coax > adapters to lengthen the cable. This is easier than > the "cut and try" technique. I have one of those > adapter kits that allows you to put together any > combination of adapters. For example, I can make a > male UHF to female UHF adapter. This will add length > to the cable easily and quickly. > > If I see that cable length is effecting matching, I > then take the time to cut a cable to that magic > length. > > Joe > > > If you have several hours of free time, and > > nothing else to do, you can use the "cut and try" > >method of finding the magic length of cable that > >transforms the output impedance of your PA to the > input >impedance of your duplexer. 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: http://docs.yahoo.com/info/terms/
