IFR COM-120B Service Manual

1-8-14 PM DEVIATION METER
CALIBRATION
PREREOUISITES:
1-B-1 POWER
SUPPLY CALIBRATION
1-8-2
TCXO/OCXO
CALIBRATlON
EQUIPMENT
REOUIRED:
1 MODULATION
ANALYZER
1
SIGNAL GENERATOR
FIGURES:
1-9
STEP
PROCEDURE
1. Apply Power
to COM-1208. Allow
5
minute warm-up
period.
2. Press REC Test Mode
Key
(3)
to access
RF Receive
Operation
Screen.
3. Set Receive Operation
Screen
Parameters
as
follows:
RF Field
101.0000
MHz
Input
ANT
Attenuation
3A
dB
Demodulation
Type
PM
lF Bandwidth
300
kHz
4. Move
cursor to Line.
5.
Press
CONFIG Soft
Function
Key F6
to access
Receiver
Audio/Data
Filters
Setup Menu.
6. Set Modulation Meters Filter
Line High-Pass Filter tor
300
Hz.
7.
Set
Modulation Meters Filter
Line Low-Pass Filter
tor 4 kHz.
8. Press EXEC
Soft
Function
Key F5.
9.
Press RETURN
Soft
Function
Key F6
to
return
to
RF Receive
Operation
Screen.
10.
Connect
Test Equipment
as shown in Figure 1-9.
11.
Access Full
Screen
Phase
Meter.
12.
Set
Phase Meter Parameters
as
follows:
Range
10 RAD
Peak
Hold
OFF
Average
OFF
13.
Set Signal
Generator
for
101 MHz
Signal FM Modulated
with 1 kHz
tone at 5
kHz
deviation
at
-10
dBm output
level.
14.
Set
Modulation
Analyzer
for PM Measurement
with
300 Hz High-Pass Filter,
3
kHz
Low-Pass
Filter
and
Peak+
detector
activated.
15.
Verify Modulation
Analyzer reading
and Phase
Meter
Reading
match
(10.7
Radians).
lf
not,
go
to
Step
12.
1-41
1-8-14 PM DEVIATION METER CALIBRATION
PREREQUISITES:
EQUIPMENT REQUIRED:
FIGURES:
STEP
1-8-1 POWER SUPPLY CALIBRATION
1-8-2 TCXO/OCXO CALIBRATION
1
1
1-9
MODULATION ANALYZER
SIGNAL GENERATOR
PROCEDURE
1. Apply Power to COM-120B. Allow 5 minute warm-up period.
2. Press REC Test Mode Key (3) to access RF Receive Operation Screen.
3. Set Receive Operation Screen Parameters as follows:
RF Field
Input
Attenuation
Demodu lation Type
IF Bandwidth
4. Move cursor to Line.
101.0000 MHz
ANT
30 dB
PM
300 kHz
5. Press CONFIG Soft Function Key F6 to access Receiver Audio/Data Filters Setup Menu.
6. Set Modulation Meters Filter Line High-Pass Filter for 300 Hz.
7. Set Modulation Meters Filter Line Low-Pass Filter for 4 kHz.
8. Press EXEC Soft Function Key F5.
9. Press RETURN Soft Function Key F6 to return to RF Receive Operation Screen.
10. Connect Test Equipment as shown in Figure 1-9.
11. Access Full Screen Phase Meter.
12. Set Phase Meter Parameters as follows:
Range
Peak Hold
Average
10 RAD
OFF
OFF
13. Set Signal Generator for 101 MHz Signal FM Modulated with 1 kHz tone at 5 kHz deviation
at -10 dBm output level.
14. Set Modulation Analyzer for PM Measurement with 300 Hz High-Pass Filter, 3 kHz
Low-Pass Filter and Peak+ detector activated.
15. Verify Modulation Analyzer reading and Phase Meter Reading match (±0.7 Radians). If
not, go to Step 12.
1-41
Scans by ArtekMedia © 2008

IFR COM-120B Specifications

General

Brand	IFR
Model	COM-120B
Category	Measuring Instruments
Language	English