Cobra MR HH425 LI VP, Serivce Manual

Page: 9 / 65

ALIGNMENT AND PROCEDURES
This unit has been fully aligned at the factory before shipment and does not normally require further adjustment.
When necessary, however, the unit may be aligned as indicated below.
Do not adjust any circuit in this radiotelephone unless you understand the circuit operation and have
experience in adjusting the radiotelephone. Tampering with the radiotelephone may upset the alignment and
lower its performance.
The test equipment listed below are used for the test setup shown in Fig. 3.1.
This test setup used either partially or totally during the following adjustments.
Test Equipment
1) DC Power Supply (7.2V DC) 0 - 15V 3A max.
2) RF Power Meter 10 W 50 Ohm 100-200 MHz
3) RF Signal Generator 100-200 MHz, 50 ohm termination
4) FM Linear Detector (FMLD) 100-200 MHz
5) Frequency Counter 1-500 MHz
6) Oscilloscope 20 MHz
7) Distortion Meter
8) Sinadder
9) Audio Oscillator
10) Toggle Switch (for use as PTT switch).
Fig. 3.1
RF POWER
METER
DC POWER
SUPPLY
AUDIO OSC
PTT
SWITCH
UNIT
UNDER TEST
OSCILLOSCOPE
SINADDER
FMLD
FREQ
COUNTER
DISTORT
METER
RF SG
SPEAKER
JACK
MIC
ANT
RX
TX
COUPLER
9