ESC 550 Source (serv.man3) - JBL Audio Service Manual (repair manual). Page 12

(Amplitude Modulation)

Function.......................................................................AM
Input Level ............................................74dB/m (5mV/m)
Generator...................................Modulation 30%, 400Hz

(Frequency Modulation)

Function.......................................................................FM
Input Level ................................................60dB/m (1mV)
Generator .................................Deviation 22.5kHz, 1kHz

Step

Signal or Sweep Generator

Reception
Frequency

Output Indicator

Connection

Adjustment

Adjust For

Connection

Frequency

1

No Signal

1710kHz

DC Digital Voltmeter

JW84

TC102

10.5+/-0.1V

2

No Signal

520kHz

Same as Step 1

L101

1.2+/-0.1V

3

Repeat Step 1 and 2 a few times

4

AM Loop Antenna at a
distance of 24 inch (60cm)
from the IRT Loop

450kHz

Point of
noninterference

IF Sweep Generator

IC101 Pin 12

T101

Flax and Max

5

Same as Step 4

620kHz

620kHz

RF Sweep Generator

R180

L102

Max

6

Same as Step 4

1400kHz

1400kHz

Same as Step 5

TC101

Max

7

Repeat Step 5 and 6 a few times

8

To the FM antenna
terminals through a
matching transformer

10.7MHz

Point of
noninterference

IF Sweep Generator

IC101 Pin 12

T102
T103

Flat and Max
Check Voltage
Between
R109=0V+/-30mV

9

Same as Step 8

98.1MHz

98.1MHz

RF Generator

Q181, Q182 “C”

SR03

Max Separation