E F Johnson Company 2422001-1 Benutzerhandbuch

ALIGNMENT AND TEST PROCEDURES

7-4

August 2000
Part No. 001-2001-200

7.2 EXCITER ALIGNMENT

The TCXO must be adjusted within 5 minutes of turn-
ing the AC power on to the repeater. Do not under any
circumstances try to set frequency later on in any of
the tests, as TCXO frequency stability cannot then be
guaranteed.

Refer to Figure 7-2 for component locations.

Refer to Figure 7-7 for equipment needed and setup
diagram.
NOTE: Some adjustments will be made using the cur-
sor "Up"/"Dn" or "PgUp"/"PgDn" keys.

W A R N I N G

SAFETY MEASURES ARE DISABLED IN TEST
MODE. ALARMS ARE ACTIVE. HOWEVER, FEA-
TURES SUCH AS THERMAL SHUTDOWN IN THE
PA ARE DISABLED.

7.2.1 PRETEST

1. Set TCXO modulation adjust RV101 fully counter-

clockwise.

2. Connect the power meter to J402.

7.2.2 VOLTAGE MEASUREMENTS

Apply power to the Exciter by plugging the

20-pin cable from the RF Interface Board into J401.

Measure the voltages at the following pins.

U406, pin 1

+12V DC

0.4V

U405, pin 1

+5V DC

0.3V

U402, pin 1

+3.5V DC

0.1V

U404, pin 7

+3.5V DC

0.1V

Figure 7-2 EXCITER ALIGNMENT POINTS

7.2.3 PROGRAM TUNE-UP CHANNEL

For Exciters operating between:
138-144 MHz or 154-172 MHz.

1. Using the PC and software, program the Synthesizer

for the Transmit frequency.

2. Press the space bar to key the Exciter.

3. Tune the VCO inductor L102 for +4.5V DC

0.05V

at TP1 (U403, pin 6).
Increase the transmit frequency by 3 MHz.
The voltage on TP1 shall be less than 7.5V.
Decrease the transmit frequency by 3 MHz.
The voltage on TP1 shall be greater than 2V.

MOD

CNTRL

Q411

Q410

Q407

Q406

A007

U406

Y401

RV401

U404

Q413

Q412

U407

U402

RV101

U405

J401

J402

Q417

Q415

Q414

Q416

Q404

Q403

U403

TP1