DISASSEMBLY
Remove the power and interface connectors before disassembling the unit. The unit is disassembled for alignment/service
by removing the six T-10 torx screws from the end plate with the antenna connector as indicated by the white arrows. The
cover with the other end plate is then slid off.
DUPLEXER
The duplexer allows the Repeater to simultaneously transmit and receive. To accomplish this, the receive input path must
suppress (notch) the transmitter signal by 65dB or more. In addition, on the transmit path, transmitter noise on the
receive frequency must be also suppressed by about 65dB. The duplexer contains four cavities, two for each path to
achieve the necessary notch depth. Because the notches are very narrow, the duplexer must be re-tuned if the frequency
of operation is changed by more than 50 kHz. Follow the procedure below to tune the duplexer:
1. Unplug the two RF cables connecting the duplexer to the main PCB.
2. View video in the attached link for Duplexer Tuning Instructions.
Instructions for Freedom R8100:
https://www.youtube.com/watch?v=V16Wz8JfJ1U
Instructions for Aeroflex 3920:
https://www.youtube.com/watch?v=jaCaCWUDI5s
Generic Tuning Instructions:
https://www.youtube.com/watch?v=tf5h_wz9G2o
https://www.youtube.com/watch?v=jtwJOSLLqG4
Note that the duplexer cables are terminated in female SMB connectors. An adapter will most likely be required to mate
with the cables to/from the test set/equipment. SMB Adapters can be purchased from most electronic component
suppliers.
Antenna Connection
RX High Pass
Connection
TX Low Pass
Connection
