Midland BR777 Alignment Procedure

1. REFERENCE TEST EQUIPMENT
A. HP8921A Cell site test set or HP8920A, B Communication Test Set with Spectrum
Analyzer option.
B. Fluke 187 Digital Voltmeter
C. HP E3615A Power supply
2. TEST POINT
A. ANTENNA
B. VCO reference voltage
C. RX audio output
D. TX Mic. Input
E. Battery Vcc
F. Up Key
G. Down Key
H. Function Key
I. Monitor Key
J. PTT Key
K. CALL Key
Note. : All key can be activated when connect with ground except Power key.
3. VCO ALIGNMENT
A. Set unit to Channel 1 and connect a voltmeter to TP1 (VCO PD).
B. Press & hold PTT.
C. Extend L303 until the voltmeter reads 1.0V.
D. Release PTT button so units is in receiving mode and monitor the voltage on TP1. The
voltage should be in the range 1.0Vds +/-0.5V
E. Set unit to channel 4.
F. Press & hold the PTT switch and observe the voltage on TP4. The voltage should be 1 –
2.4 Vdc.
G. Release PTT and observe the voltage on TP1. The voltage should read between 1.0 – 2.4
Vdc.
Note : VCO shield-can should be soldered after VCO alignment is finished.
4. TRANSMITTER FREQUENCY ALIGNMENT
A. Press & hold the PTT button.
B. Align CT201 trimmer capacitor such that the output frequency is equal to the channel
frequency with a maximum error of +/- 200 Hz. CT201 is located on the left side of VCO
shield can.
BR777
ALIGNMENT PROCEDURE
: Test point is not prepared. Use antenna contact with
ANTENNA_GND_T(antenna ground).
: Test point 1 is prepared.
: Test point SPKOUT is prepared.
: Test point MICIN is prepared.
: Test point BAT is prepared.
: Test point UP is prepared.
: Test point DW is prepared.
: Test point Menu is prepared.
: Test point SCAN is prepared.
: Test point PTT is prepared.
: Test point CALL is prepared.
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