Where did you find (what is) the formula for jumpers from the duplexer > to the transmitter and receiver? > > N7HQR
http://www.repeater-builder.com/ge/duptuning.html I have been told that this formula, explained in Paragraph 4 of the above site, also works for the electrical length from the duplexer to the TX-RX. Others say that only the TX is SOMETIMES critical and a Z-Matcher will also work. If anyone feels I have misunderstood this information, please let me know. When inserting any in-line devices in to your repeater's feed line, be sure any added feed line(s) used to connect the device (like a watt meter) are at least one half wave length of your transmit frequency. You can calculate the electrical length required by dividing your frequency in to 5904 and multiplying the result by the velocity factor of your feed line. This will yield the 1/2 electrical wave length in inches, tip to tip including the RF connector. An example, 5904/442.275 = 13.35, now multiply 13.35 by the velocity factor of the feed line, I'll use 66%, 13.35 * .66 = 8.81 inches. You can use any multiple of the result 8.81, 17.6, 26.43, 35.24. Also try to use a good watt meter like the Bird, the less expensive watt meters are not a true power measuring device but a glorified voltage meter which can be easily fooled by hi Q as found in a duplexer. JIM KA2AJH ----- Original Message ----- From: "Daron J. Wilson" <[EMAIL PROTECTED]> To: <Repeater-Builder@yahoogroups.com> Sent: Sunday, March 28, 2004 6:38 PM Subject: RE: [Repeater-Builder] Duplexer Cable Legnth > > >> Where did you find (what is) the formula for jumpers from the duplexer > to the transmitter and receiver? > > N7HQR > > > > > > > > Yahoo! Groups Links > > > > > 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/
