Ramsey Electronics COM3010 User Manual page 54

TYPICAL TEST PROCEDURES
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Set up the COM 3010 to generate and monitor the same frequency. The COM 3010 can
be linked for either the transmitter or receiver frequency.
STEP-1 TUNING THE RECEIVER SIDE OF THE DUPLEXER (RX PASS)
1. The receive side of the duplexer is tuned to reject the transmitter noise at the transmit
frequency.
2. Connect RF OUT to the duplexer antenna port as shown in FIGURE-1 below. This is
done in order to inject each signal for the test. -50 dbm output is a good starting point.
Do not disconnect this as it will remain connected this way for the entire procedure.
3. Set the COM 3010 Generator for the repeater transmitter frequency and generate a -50
dbm signal.
4. Attach the 50 Ohm load directly to the duplexer transmitter port.
5. Connect the RECEIVE IN to the duplexer receiver port.
Property of Ramsey Electronics, Inc.
6. The receiver in the RSSI mode is now connected. Adjust the cavity closest to the
RECEIVE IN connection for minimum signal or greatest notch. This will also be the
noisiest signal (maximum negative RSSI indication). Next, do the same for the other
cavities in line.
Do not reproduce or distribute.
7. You may need to increase the generator output level and readjust all in line cavities to
get the best tuning points as the rejection is increased. You can determine the rejection
in db by adding the generator db value to the RSSI value. Example Generator -40dbm
and Receiver RSSI -110 dbm =70 db rejection
8. The locking nuts on the Cavity tuning shafts should be hand tightened and the rejection
tuning re-measured.
TX PASS TX PASS
TUNE TO NOTCH RX
54
FIGURE-1
RX PASS – RECEIVER SIDE
RX PASS RX PASS
TUNE TO NOTCH TX
50? LOAD