Midland BR777 Manual

BR777
ALIGNMENT PROCEDURE
Page 1
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 : Test point is not prepared. Use antenna contact with
ANTENNA_GND_T(antenna ground).
B. VCO reference voltage : Test point 1 is prepared.
C. RX audio output : Test point SPKOUT is prepared.
D. TX Mic. Input : Test point MICIN is prepared.
E. Battery Vcc : Test point BAT is prepared.
F. Up Key : Test point UP is prepared.
G. Down Key : Test point DW is prepared.
H. Function Key : Test point Menu is prepared.
I. Monitor Key : Test point SCAN is prepared.
J. PTT Key : Test point PTT is prepared.
K. CALL Key : Test point CALL is prepared.
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
Page 2
5. TRANSMITTER OUTPUT POWER CONFIRMATION
A. Set unit to channel 1 and power Hi mode.
B. Press & hold the PTT button.
C. Transmit power should normally be between 1.0W to 1.5W.
6. TRANSMITTER DEVIATION ALIGNMENT
A. Connect an audio generator (600 ohms) to the ear jack. The audio frequency should be set
at 1KHz with a level of 200mV RMS.
B. Connect an FM deviation meter (communications test set) to Antenna contact. Set the
monitor to read peak to peak divided by two [(pk-pk)/2] deviation. Set filter of equipment
from 25Hz to 15KHz.
C. Press & hold the PTT button.
D. Align RV2 for +/- 2.0 kHz deviation (+/-0.1KHz). RV2 is located on the bottom of the VCO
shield can.
E. Decrease audio generator level until deviation reads +/- 1.5 kHz (approximately 4mV) and
record generator level. Level should be between 2 mV and 5 mV.
F. Confirm that transmit audio distortion is less than 5%.
7. RECEIVER ALIGNMENT
A. Set the output level of the RF signal generator for -47dBm. The generator should be set for
1.5 kHz deviation at 1 kHz audio.
B. Set volume level 4 (It is initial.).
C. Connect Audio analyzer to SPKOUT.
D. Set equipment filter 25Hz to 15KHz.
E. Align CF3 to get a maximum output level & a minimum distortion and confirm that Rx audio
distortion is less than 3%.
F. Confirm that Rx Sensitivity is less than –120dBm (nominally –123dBm) by reducing the
output level of the RF signal generator until a 12 dB SINAD reading is achieved.
H. Set SSG output level until 9dB sinad sensitivity and confirm until the unit is un-squelched.
I. Set signal generator level to –47dBm.
J. With 1.5KHz deviation at 1KHz modulation, set volume for maximum audio. Audio level
should be on over than 1.5Vrms.
8. BATTERY INDICATOR CONFIRMATION
A. Set unit to receiving mode. Don’t set transmitter mode..
B. Set power supply voltage to 3.7 Vdc.
C. Decrease power supply voltage until low battery icon blinks.
9. POWER OFF CURRENT CONSUMPTION
A. Set power supply voltage to 3.7 Vdc and connect to unit.
B. Confirm current. It must be less than 100uA.

BR777
ALIGNMENT PROCEDURE
Page 3
10. FREQUENCIES TABLE
Display # Freq. MHz Display # Freq. MHz
1 464.5000 29 462.9125
2 464.5500 30 464.4875
3 467.7625 31 464.5125
4 467.8125 32 464.5375
5 467.8500 33 464.5625
6 467.8750 34 466.0375
7 467.9000 35 466.0625
8 467.9250 36 466.0875
9 461.0375 37 466.1125
10 461.0625 38 466.1375
11 461.0875 39 466.1625
12 461.1125 40 466.1875
13 461.1375 41 466.2125
14 461.1625 42 466.2375
15 461.1875 43 466.2625
16 461.2125 44 466.2875
17 461.2375 45 466.3125
18 461.2625 46 466.3375
19 461.2875 47 466.3625
20 461.3125 48 467.7875
21 461.3375 49 467.8375
22 461.3625 50 467.8625
23 462.7625 51 467.8875
24 462.7875 52 467.9125
25 462.8125 53 469.4875
26 462.8375 54 469.5125
27 462.8625 55 469.5375
28 462.8875 56 469.5625

BR777
LABORATORY TESTING PROCEDURES
Page 1
UNIT TEST - (UNIT ASSEMBLED)
TEST PREPARATION
1) Install 1 Lithium Ion battery.

Left bottom terminal is the system plus polarity

Right bottom terminal is the system minus polarity.
2) Press the power button.
SYSTEM TEST
1) Radiated Transmit and Receive performance may be observed.
2) Audio out & Audio in are available at the Headset jack.
LABORATORY TEST - (UNIT UN-ASSEMBLED)
TEST PREPARATION
1) Disassemble unit (4 screws – 2 behind battery cover). Remove the back cabinet.
2) Remove the antenna and install a 50 ohm coax cable in its place.
3) Either clip alligator leads or solder test leads to the power supply connections. The
positive terminal is the lower right terminal. The negative terminal is the lower left
terminal. (battery side view)
4) Connect 3.7VDC power source to the terminals, observing correct polarity.
5) Connect an 16-ohm load through the Headset jack (right terminal of 2.5mm stereo
phone plug).
6) Connect a audio generator with 10uF coupling capacitor through the Headset jack
(left terminal of 2.5mm stereo phone plug).
7) Select desired channel 1- 4 using CH up/down keypad switch.

BR777
LABORATORY TESTING PROCEDURES
Page 2
SPECIFIC TEST METHODS AND GUIDANCE
Modulation Characteristics – (paragraph 2.1047(a) of the Rules)
FOR TX AUDIO FILTER RESPONSE
1. Connect audio generator with 10uF coupling capacitor to microphone input jack.
Press PTT button.
2. Connect RF output with modulation meter. (Filters of modulation meter should be
set to a 50Hz to 15KHz.)
3. Adjust audio generator about 5-6mVrms for 0.75KHz modulation.
4. While transmitting, sweep generator and note measurement.
5. Please compensate the back-ground noise level.
Modulation Characteristics – (paragraph 2.1047(b) of the Rules
FOR TX AUDIO LOW PASS FILTER RESPONSE.
1. Connect audio generator with 10uF coupling capacitor to microphone input jack.
Press PTT button.
2. Connect AC voltmeter or other test equipment via jumper wire to the junction of R39
& C53.
3. Adjust audio generator for 200mV.
4. While transmitting, sweep generator and note measurement.
Occupied Bandwidth – (paragraph 2.1049(c) of the Rules)
1. Connect an audio frequency sweep generator with 10uF coupling capacitor to
microphone input jack.
2. Adjust audio generator to a frequency of 2500Hz and a level of 100mV rms (+16dB
above 10-12mV per FCC).
3. With a spectrum analyzer, transmit the radio and monitor the transmitter though an
antenna.
4. Note required measuements per FCC.

BR777
PRODUCTION SPECIFICATION
Page 1
1. GENERAL SPECIFICATION
Items Specifications
1 Tx Frequency range 461.0375MHz ∼469.5625MHz
2 Tx VCO Frequency range Same as item 1
3 RX Frequency range Same as item1
4 RX VCO Frequency range 4439.6375MHz ∼448.1625MHz ( Lower Heterodyne )
5 Channel Number
Channel Spacing 4CH
25KHz
6 Frequency Control PLL Synthesizer with Temperature Compensated Crystal
Reference
7 IF frequencies 21.4 MHz for 1’st IF
450KHz for 2’nd IF
8 Modulation FM (F3E emissions)
9 Standard Test Modulation signal Modulated audio Frequency : 1KHz
Test modulation : +/-1.5KHz
10 TX Frequency stability Max. +/-2.5ppm ( -30℃to +60℃)
Nominal test temperature Range 25℃+/- 5℃ 11
Extreme operating temperature
Range -20℃to +50℃
12 Antenna Impedance 50 ohm +/- 25 ohm
13 Power source 1 Lithium Ion battery
Test Power Supply Voltage 3.7Vdc. +/-0.1Vdc 14 Extreme Supply Voltage Range 3.2Vdc to 4.2Vdc
15 Battery life time ( Typ. 5/5/90 duty) Min. 45 Hours
16 Microphone Self contained Electret
17 Speaker Self contained 16 ohm

BR777
PRODUCTION SPECIFICATION
Page 2
2. DETAILED SPECIFICATION
A. RECEIVER SECTIONS * Normal test condition *
TYP. LIMIT
1. MAXIMUM USABLE SENSITIVITY
* 1KHz +/-1.5KHz DEV.
* REF. CHANNEL 1 & 4
-120dBm <-118dBm
2. 20dB QUIETING SENSITIVITY
* 1HKz +/-1.5KHz DEV.
* REF. CHANNEL 1 & 4, 12dB SINADDER
-114dBm <-110dBm
3. ADJACENT CHANNEL TWO SIGNAL
SELECTIVITY & SENSITIZATION
* +/- 1 CHANNEL SPACING
>50dB
4. INTER-MODULATION SPURIOUS RESPONSE
ATTENUATION >50dB
5. SPURIOUS EMISSIONS
* CONDUCTIVE CONNECTION <-53dBm
6. RECEIVE FREQUENCY RESPONSE
* REF. 1KHz +/-1.5KHz DEV.
250Hz
3KHz
-18.0dB
-12.0dB
+/-2.0dB
+/-3.0dB
7. AUDIO OUTPUT LEVEL
* REF. 1KHz +/-1.5KHz DEV.
* (No LOAD )
* Volume Max.
1.8V >1.3V
8. AUDIO OUTPUT DISTORTION
* REF. 1KHz +/-1.5KHz DEV.
* ( No LOAD ) <5%
9. MAX. S/N RATIO
* REF. 1KHz +/-1.5KHz DEV.
* ( No LOAD ) 36 dB >30dB
10. RX VCO REF. VOLTAGE
* REF. CHANNEL 1
* REF. CHANNEL 4
1.0V
2.0V
+/-0.3V
+/-0.3V
11. SQUELCH THRESHOLD
* REF. 1KHz +/-1.5KHz DEV.* 9dBsinadder -3dB - +3dB
16. CURRENT CONSUMPTION
* Un-squelched Volume Max.
* Squelched
* Power Off
200mA
35mA
50uA
+/-40mA
<40mA
<100uA

BR777
PRODUCTION SPECIFICATION
Page 3
B. TRANSMITTER SECTIONS
TYP LIMIT
1. TRANSMITTER FREQUENCY TOL.
* REF. CHANNEL 1 <+/-200Hz
2. TRANSMITTER RF POWER
* REQUIRED CONDUCTIVE CONNECTION
* REF. CHANNEL 1 Hi Power (DC3.7V)
Low Power
1.2W
0.4W
+0.3W / -0.2W
+0.3W / -0.2W
3. TRANSMITTER OCCUPIED BANDWIDTH
* REQUIRED CONDUCTIVE CONNECTION
* REF. CHANNEL 1 @12.5KHz
<-50dBC
4. TRANSMITTER SPURIOUS
* REQUIRED CONDUCTIVE CONNECTION
* REF. CHANNEL 8
<-50dBC
5. MODULATION SENSITIVITY
* REF. 1KHz AUDIO
* CHANNEL 1 , @+/-1.5KHz 4mV +/-2mV
6. MODULATION LIMITING
* REF. 1KHz AUDIO, CHANNEL 1
* (INPUT AUDIO ; 200mVrms) +/-2.2KHz +/-0.2KHz
7. CTCSS CODE DEVIATION
* CH 1
* CH38
0.4KHz
0.4KHz
+/-0.1KHz
+/-0.1KHz
8. MODULATION AUDIO DISTORTION
* REF. 1KHz AUDIO +/-1.5KHz 3% <5%
8.TX AUDIO FREQUENCY RESPONSE
* REF. 1KHz AUDIO, CHANNEL 1
* ( INPUT AUDIO ; 3mVrms )
250Hz
3KHz
6KHz
-31.0dB
+6.0dB
-16.0dB
+/-3.0dB
+/-3.0dB
+/-3.0dB
9. TX MODUALTION S/N
* REF. 1KHz AUDIO, CHANNEL 1
* ( REF. INPUT AUDIO ; 12mVrms ) >30dB
10. TX VCO REF. VOLTAGE
* CHANNEL 1
* CHANNEL 14
1.0V
2.0V
+/-1.0V
+/-1.0V
11. CURRENT CONSUMPTION
* DC5V Power Hi 800mA +/-200mA

BR777
TX AUDIO TEST RESULT
Page 1
Frequency Response of Audio Low Pass Filter (150mV input)
3K 4K 5K 6K 7K 8K 9K 10K 15K 20K
#1 0 -8.90 -15.80 -21.10 -25.30 -28.90 -32.00 -34.50 -45.40 -52.1
#2 0 -9.00 -15.90 -21.20 -25.30 -28.90 -31.90 -34.50 -45.20 -50.2