Codan Radio MT-4E Analog and P25 Digital - Maintenance Guide - Manual (Page 55)

MT-4E ANALOG & P25 DIGITAL RADIO SYSTEMS | MAINTENANCE GUIDE
Chapter 5: Codan Radio System Testing Page 47
Transmitter Modulation Fidelity Testing
Connect the IFR 2975 and Codan Radio as shown in Figure 5-33.
Figure 5-33: Transmitter Modulation Fidelity Testing
On the IFR 2975, recall Codan setup 9 (Tx_ModFid) from your internal drive. Enter the correct RF
frequency on the IFR 2975 and set the transmitter front panel switch to NORM. The MIC MODE switch
on the front panel can be set to either Digital or Analog (this test does not make use of the front panel
switch).
In the transmitter RSS, enter the Service section and click on “Test Patterns”. Ensure the transmitter
frequency is in the frequency box. In the Select Pattern window select “C4FM Modulation Fidelity”.
Click on the “Key Tx” button as shown in Figure 5-34 and the transmitter will begin generating the test
pattern out the RF output.
Figure 5-34: RSS Transmitter Modulation Fidelity Test Pattern
TRANSMITTER
CNTL
BUS
MIC RF OUT
A D
ANALOG
DIGITAL
NORM
OFF
KEY TX
MIC MODE
REF IN
USB
FREQUENCY (MHz)
MADE IN CANADA MODEL # CODE
VOL
SYSTEM REGULATOR
METER
+
-
MADE IN CANADA
ON
OFF
SPKR INT EXT EXT
SPKR
OFF
POWER ON
2
1
5
4
3
6 7 8
11
10
9
FUNCTION 12
Computer running RSS
USB from
Computer to Tx
Tx RF OUT to T/R port on IFR 2975
HELP MODE
TAB
SHIFT
+
-
.
BKSP
HOLD
RETURN
ESC ENTER POWER
1 2 ABC 3 DEF
JKL MNO GHI 6 5 4
TUV WXYZ PQRS 9 8 7
# 0 *
VOLUME
SQUELCH
GEN T/R ANT
125 W MAX MIC AUDIO I/O DVM CH2 CH1 SCOPE TEST PORT
100V MAX 100V MAX 100V MAX