15
Appendix H: Viavi CX300 Tests
MAINTENANCE GUIDE | MT-4E ANALOG & P25 DIGITAL RADIO SYSTEMS
Receiver Reference Oscillator Adjustment
Connect the CX300 and Zetron Radio as shown in Figure H-13.
Figure H-13: Receiver Reference Oscillator Testing
The reference oscillator test on the receiver requires a connection directly into the Synthesizer, which uses an
SMB connector. Disconnect the SMB cable from the LO output of the synthesizer and connect the small SMB-
SMB cable to the SMB jack that is mounted on the Synthesizer (beneath the RF Preselector). The SMB-BNC
adapter is required to connect this point to the RF INPUT on the CX300 as shown in Figures H-14 (VHF and UHF
400 MHz Receiver) and H-15 (UHF 700 / 800 / 900 MHz Receiver).
Figure H-14: VHF and UHF 400 MHz Receiver Reference Oscillator Connection
Synthesizer L.O. output
from Receiver to
RF INPUT on CX300
Computer running RSS
USB from
Computer to Rx
RECEIVER
OFF
NORM
SQ. DISABLE
BUS
CNTL
A D
RF I N
IN
REF
USB
FREQUENCY (MHz)
MADE IN CANADA
MODEL # CODE
VOL
SYSTEM REGULATOR
METER
+
-
MADE IN CANADA
ON
OFF
EXT
SPKR
INT
EXT
SPKR
OFF
POWER
ON
2
1
5
4
3
6
7
8
11
10
9
FUNCTION
12
on CX300
SMB-SMB
To RF INPUT
cable
LO output of
synthesizer
