Standard Horizon HX751 User manual

1
SERVICE MANUAL
Floating Marine Transceiver
HX751
EM032N97B
HX751
CLR
WX

2
Specifications
General
Frequency Ranges: TX: 156.025 MHz - 157.425 MHz
RX: 156.050 MHz - 163.275 MHz
Channel Spacing: 25 kHz
Frequency Stability: ±10 ppm (–4 °F to +140 °F [–20 °C to +60 °C])
Emission Type: 16K0G3E
Antenna Impedance: 50 
Supply Voltage: 7.4V DC, Negative Ground (Battery Terminal)
Current Consumption: 280 mA (Receive, Typical at AF MAX.)
50 mA (Standby)
10 mA (Standby, Saver On)
1.6 A / 1.5 A / 1.0 A / 0.7 A
(TX: 6 W / 5 W / 2.5W / 1W)
Operating Temperature: –4 °F to +140 °F (–20 °C to +60 °C)
Thermometer Operating Range: 14 °F to +140 °F (–10 °C to +60 °C)
Case Size (W x H x D): 2.44” x 5.57” x 1.61” (62 x 141.5 x 41 mm) w/o knob & antenna
Weight (Approx.): 10.8 oz (305 g) w/FNB-V99LI, Belt Clip, & Antenna
Transmitter
RF Power Output: 6 W / 5 W / 2.5 W / 1 W (@7.4 V )
Modulation Type: Variable Reactance
Maximum Deviation: ±5 kHz
Spurious Emission: –75 dBc typical
Microphone Impedance:2k
Receiver
Circuit Type: Double-Conversion Superheterodyne
Intermediate Frequencies: 1st: 47.25 MHz
2nd: 450 kHz
Adjacent Channel Selectivity: 70 dB typical
Intermodulation: 70 dB typical
Ham & Noise Ratio: 40 dB typical
Sensitivity: 0.25 μV for 12 dB SINAD
Selectivity: 12 kHz / 25 kHz (–6 dB / –60 dB)
AF Output (Internal SP): 700 mW @16 for 10 % THD (@7.4 V)
Performance specifications are nominal, unless otherwise indicated, and are subject to change without notice. Measured in accor-
dance with TIA/EIA-603.
Important Note
The HX751 was assembled using Pb (lead) free solder, based on the RoHS specification.
Only lead-free solder (Alloy Composition: Sn-3.0Ag-0.5Cu) should be used for repairs performed on this appara-
tus. The solder stated above utilizes the alloy composition required for compliance with the lead-free specification,
and any solder with the above alloy composition may be used.

3
Exploded View & Miscellaneous Parts
CP9173001 (COL:BLAC)
CP9173002 (COL:BLUE)
BELT CLIP ASSY




CP9170020 (COL:BLAC, USA)
CP9170021 (COL:BLUE, USA)
CP9170022 (COL:BLAC, EXP)
CP9170023 (COL:BLUE, EXP)
CP9170024 (COL:BLAC, AUS)
CP9170025 (COL:BLUE, AUS)
CP9170026 (COL:BLAC, EU)
CP9170027 (COL:BLUE, EU)
CP9170028 (COL:BLAC, UK)
CP9170029 (COL:BLUE, UK)
FRONT PANELASSY
RA099980A
RELEASE KNOB (BATTERY)
RA099990A
LATCH PLATE (BATTERY)
RA1184200
RUBBER PACKING (CASE)
RA0999700 (x2 pcs)
COIL SPRING (TERMINAL)
CS1991101
TERMINALASSY
RA099220A
RUBBER PACKING (TERMINAL)
RA0434100
SHEET (M-TEX1131)
CP9169001
CHASSIS ASSY
RA0919700
O RING (6X2.2)
RA1030600
MIC HOLDER RUBBER
G6090200
LCD
RA1000100 (Lot. 1~23)
RA100010A (Lot. 24~)
LIGHT GUIDE (LCD)
RA1000200
REFLECTOR SHEET
RA1087000 (Black; Lot. 15-16)
RA1083900 (Blue; Lot. 15-16)
RA108700A (Black; Lot. 17-23)
RA118390A (Blue; Lot. 17-)
RA108700B (Black; Lot. 24-)
KNOB SCREW (SP/MIC)
RA1030500 (BLACK)
RA1184100 (BLUE)
RUBBER CAP (MIC)
RA1199600
RUBBER KNOB
(Rubber keypad)
RA046760A
O RING (ANT)
RA039980A
LIGHT GUIDE (LED) RA1084700
O RING (3.4X0.95)
RA1193300
RUBBER KNOB (PTT)
(Rubber cover)
RA0999400 (Lot. 1~18)
RA099940A (Lot. 19~)
HOLDER (PTT)
RA103720A
MASK SHEET (32x28)
RA051780B
CAUTION LABEL (FCC)
RA0478700
SHEET (5.6M-TEX1131)
CP9171002 (COL:BLAC)
CP9171003 (COL:BLUE)
REAR PANEL ASSY
Non-designated parts are available only as
part of a designated assembly.
RA1000300
INTER CONNECTOR
REF.





VXSTD P/N
U24108020
U24112020
U9900019
U9900026
U9900068
DESCRIPTION
BIND HEAD TAPTITE-B2X8SUS
BIND HEAD TAPTITE-BM2X12SUS
PAN HEAD TAPTITE-B M2X6
PAN HEAD TAPTITE-B M2X8
PAN HEAD TAPTITE-B M2X4NI#3
QTY.
2
4
3
5
9
















RA1007900
SHEET (RADIATION)
MAIN ASSY
RA1084800 (x 4 pcs)
WASHER 4.3X2.0
DESCRIPTION
CAT460 Antenna (BLACK)
CAT460 Antenna (BLUE)
FNB-V99LI Li-Ion Battery Pack
NC-88B 120VAC Wall Charger
NC-88C 230VAC Wall Charger
NC-88U 230VAC Wall Charger
CD-39 Charger Cradle
E-DC-19A DC Cable with Cigarette Lighter Plug
(w/o CE, UK)
BOTTOM COVER (HX751)
QTY.
1
1
1
1
1
1
VXSTD P/N
Q3000176
Q3000235
AAF99X002
AAD88X002
AAD88X003
AAD88X004
AAF94X001
Q9000821
RA1213700

4
Note

5
Block Diagram