Adjustment Of Reject Notch On Receive Leg - Motorola R-2001D Operator's Manual

CAVITY & DUPLEXER TUNING
BANDPASS WITH REJECT NOTCH
B.
Adjustment of Reject Notch on Receive Leg
1. Connect the Analyzer's RF In/Out to the in-service duplexer as shown in figure 4-22. Disconnect the cable at the .----../
duplexer receiver port that comes from the receiver. Move the Analyzer's RF In/Out cable from the duplexer
antenna port to the duplexer receiver port. Connect a power-rated dummy load to the duplexer antenna port.
4.
Set DISPLAY to Spectrum Analyzer, FUNCTION switch to Monitor, and attenuator to -30 dB. Verify that the
display's center frequency reads the same as the transmit frequency in step A-7 above.
3. Key the transmitter and adjust the reject notch adjustments on the duplexer receive leg cavities for minimum
signal on the display. Change the attenuator, as necessary, to keep the signal on the display.
4. Loosen the cavity reject adjustment nut and slide it within its slot while watching the display. Tighten the adjust-
ment nut. Be careful not to mistune the rejection adjustment. Fine-tune the rejection adjustment by turning the
bandpass knob a maximum +/-15°. This completes the duplexer receiver leg reject notch adjustment.
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