ARMY
TM 11-5820-553-10
NAVY EE150-SN-OPl-010/E110-PRC 70
OPERATOR’S MANUAL
RADIO SET AN/PRC-70
(NSN 5820-01-062-8246)
This copy is a reprint which includes current
pages from Changes 1 and 2.
DEPARTMENTS OF THE ARMY AND THE NAVY
19 FEBRUARY 1982
TM 11-5820-553-10/EE150-SN-OPl-010/E110-PRC 70
WARNING
Serious injury or death could result to personnel if the
whip antenna comes in contact with power lines.
When operating in HI PWR with the whip antenna, DO
NOT TOUCH the antenna when in transmit mode—an
RF burn can result.
This decal is located near the WIRE terminal and WHIP
antenna on the front panel of the radio set. It is applicable to BOTH long wire and whip antenna usage.
WARNING
Adequate ventilation should be provided while using
TRICHLOROTRIFLUOROETHANE. Prolonged
breathing of vapor should be avoided. The solvent
should not be used near heat or open flame; the products of decomposition are toxic and irritating. Since
TRICHLOROTRIFLUOROETHANE dissolves
natural oils, prolonged contact with skin should be
avoided. When necessary, use gloves which the solvent
cannot penetrate. If the solvent is taken internally, consult a physician immediately.
TM 11-5820-553-10/EE150-SN-OPl-010/E110-PRC 70
WARNING
A potential RF radiation hazard exists when Radio Set
AN/PRC-70 is operated in HI PWR, with the whip
antenna, either 6 or 9 foot (2 or 3 meters). This hazard is
increased when the radio is operated in the portable
(backpack) mode. For protection against these hazards,
observe the following safeguards:
a. Use a dummy load when operating the radio, if
possible, such as when performing Preventive Maintenance Checks and Services (PMCS) to determine
equipment readiness/availability.
b. Operate the radio in the off-the-back (fieldemplaced) mode, if possible, using either the doublet or
the long-wire antenna.
c. If a whip antenna must be used for transmissions
in the field-emplaced mode, use a microphone cable
long enough to maintain a distance of at least 1.7 feet
(50 centimeters) from the antenna.
d. If the radio must be operated in the portable (onthe-back) mode, use LO PWR or do not transmit for
longer than 30 seconds out of any 6-minute interval.
CAUTION
Do not attach antenna to this unit if high power
transmitters in the range 2-76 MHz are being operated
within 200 feet.
Change 1
A
TM 11-5820-553-10/EE150-SN-OPl-010/E110-PRC 70
CAUTION
FREQUENCY STABILITY CHECK
The AN/PRC-70 radio requires a radio frequency
stability check annually. Refer to your organizational
maintenance schedule to ensure your radio does not
become due for this check during a mission.
CAUTION
Handcrank Generator G-76/G must be producing
power BEFORE the AN/PRC-70 is turned on. Failure
to do this may damage the radio.
B
Change 1
TM 11-5820-553-10
TM 11-5820-553-10
D
TM 11-5820-553-10
SAFETY STEPS TO FOLLOW IF SOMEONE
IS THE VICTIM OF ELECTRICAL SHOCK
DO NOT TRY TO PULL OR GRAB THE INDIVIDUAL
IF POSSIBLE
, TURN OFF THE ELECTRICAL POWER
IF YOU CANNOT TURN OFF THE ELECTRICAL
POWER, PULL, PUSH, OR LIFT THE PERSON TO
SAFETY USING A WOODEN POLE OR A ROPE OR
SOME OTHER INSULATING MATERIAL
SEND FOR HELP AS SOON AS POSSIBLE
AFTER THE INJURED PERSON IS FREE OF
CONTACT WITH THE SOURCE OF ELECTRICAL
SHOCK, MOVE THE PERSON A SHORT DISTANCE
AWAY AND IMMEDIATELY START ARTIFICIAL
RESUSCITATION
TM 11-5820-553-10
F
TM 11-5820-553-10
EE150-SN-OPI-01B/E110-PRC 70
C2
CHANGE
DEPARTMENTS OF THE ARMY
AND THE NAVY
NO. 2
Washington, DC, 1 August 1987
OPERATOR’S MANUAL
RADIO SET AN/PRC-70
(NSN 5820-01-062-8246)
TM 1l-5820-533-10/EE150-SN-OPI-010/E110-PRC 70,
19 February 1982 is changed as follows:
1. Remove old pages and insert new pages as indicated
below. New or changed material is indicated by a vertical bar in the margin of the page. Added or revised
illustrations are indicated by a vertical bar adjacent to
the identification number.
Remove pages
i through iv . . . . . . . . . . . . . . . . . .
1-1 and 1-2 . . . . . . . . . . . . . . . . . . . .
1-5 through 1-10 . . . . . . . . . . . . . . .
2-3 AND 2-4 . . . . . . . . . . . . . . . . . . .
2-11 and 2-12 . . . . . . . . . . . . . . . . . .
2-15 through 2-26 . . . . . . . . . . . . . .
4-3 and 4-4 . . . . . . . . . . . . . . . . . . . .
4-7 through 4-10 . . . . . . . . . . . . . . .
4-17/(4-18 blank) . . . . . . . . . . . . . . .
A1 and A2 . . . . . . . . . . . . . . . . . .
Insert pages
i through iv
1-1 and 1-2
1-5 through 1-10
2-3 and 2-4
2-11 and 2-12
2-15 through 2-26
4-3 and 4-4
4-7 through 4-10
4-17/(4-18 blank)
A1 and A2
2. File this change sheet in front of the publication for
reference purposes.
Distribution authorized to the Department of Defense and DOD contractors only
for official use or for administration or operational purposes. This determination
was made on 26 March 1987. Other requests for this document will be referred
Commander, US Army Communications-Electronics Command and Fort
Monmouth, ATTN: AMSEL-ME-P, Fort Monmouth, NJ 07703-5000.
DESTRUCTION NOTICE–Destroy by any method that will
prevent disclosure of contents or reconstruction of the
document.
TM 11-5820-553-10
EE150-SN-OPl-010/E110-PRC 70
TECHNICAL MANUAL
NO. 11-5820-553-10
TECHNICAL MANUAL NO.
EE150-SN-OPI-010/E110-PRC 70
DEPARTMENTS OF THE
ARMY AND THE NAVY
Washington, DC, 19 Feb 82
OPERATOR’S MANUAL
RADIO SET AN/PRC-70
(NSN 5820-01-062-8246)
REPORTING ERRORS AND
RECOMMENDING IMPROVEMENTS
You can help improve this manual. If you find any
mistakes or if you know of a way to improve the procedures, please let us know. Mail your letter, DA Form 2028
(Recommended Changes to Publications and Blank
Forms), or DA Form 2028-2 located in back of this
manual direct to: Commander
Electronics Command and Fort Monmouth, ATTN:
AMSEL-ME-MP, Fort Monmouth, New Jersey 07702-5000.
, US Army Communications-
For Navy, mail comments to the Commander
Naval Warfare Systems Command,
Washington, DC 20363-5100.
In either case, a reply will be furnished direct to you.
Chapter
Section I. General
1. INTRODUCTION
Scope . . . . . . . . . . . . . . . . . . . 1-1
Consolidated Index of Army
Publications and Blank
Forms . . . . . . . . . . . . . . . . . . . .1-2
Maintenance Forms,
Records, and Reports . . . . . . . .1-3
Reporting Equipment Im-
provement Recommendations
(EIR) . . . . . . . . . . . . . . . . .... . . . . . . . . . . 1-4
Warranty Information . . . . . . . .1-5
II. Description and Data
Equipment Characteristics,
Capabilities, and Features . . . . .1-6
EE150-SN-OPI-01B/E110-PRC 70/Change 2
ATTN: SPAWAR8122,
, Space and
Paragraph
Page
1-1
1-1
1-1
1-2
1-2
1-2
i
TM 11-5820-553-10
Chapter 2
Section I.
Section II.
III.
IV.
Paragraph
Location and Description
of Major Components.
System Application. . . . .
Tabulated Data . . . . . . .
OPERATING
INSTRUCTIONS
Controls and Indicators
Damage From Improper
Settings . . . . . . . . . . . . .
Operator/Crew Controls
Operation Under Usual
Conditions
Types of Operation . . . . .
Preliminary Starting
Procedures . . . . . . . . . .
Portable Configuration.
Fixed Configuration. . . . .
Initial Adjustments. . . . .
Operating Procedures . . .
Operation Under Unusual
Conditions
Operation Under Emer-
gency Conditions . . . . .
Recognition and Identi-
fication of Jamming . . .
Antijamming Procedures . . . . . . . . 2-11
Preparation for Movement
Portable Configuration
Movement . . . . . . . . . . . . . . . . . . . . .2-12
Fixed Congifuration
Movement . . . . . . . . . . . . . . . . . . . . 2-13
Fixed Voice Configura-
tion Movement . . . . . . . . . . . .2-14
CW or FSK Configuration
Movement . . . . . . . . . . . . . . . . . . . . . 2-15
Retransmit Configuration
Movement . . . . . . . . . . . . . . . . . . . . . . 2-16
. . . . 1-7
1-8
. . . .
1-9
. . . .
2-1
2-2
2-3
2-4
. . .
. . . . 2-5
. . . . 2-6
. . . . 2-7
. . . 2-8
. . . 2-9
2-10
Page
1-3
1-7
1-7
2-1
2-1
2-5
2-5
2-5
2-7
2-15
2-15
2-21
2-23
2-24
2-26
2-26
2-27
2-27
2-28
Chapter 3.
Section I.
ii
MAINTENANCE
INSTRUCTIONS
Tools and Equipment
General. . . . . . . . . . . . . . . . . . . . . .3-1
II.
Lubrication Instructions
General . . . . . . . . . . . . . . . . . . .. . . . . . .3-2
3-1
3-1
TM 11-5820-553-10
III.
IV.
Chapter 4.
Section I.
II.
Preventive Maintenance
Checks and Services
(PMCS)
General . . . . . . . . . . . . . . . . . . . .3-3
Preventive Maintenance
Checks and Services. . . . . . . .3-4
Maintenance of the Radio
Set . . . . . . . . . . . . . . . . . . . . ..3-5
Troubleshooting
General . . . . . . . . . . . . . . . . . . .3-6
V.
Maintenance of Radio Set
General . . . . . . . . . . . . . . . . . . .3-7
MATERIEL USED IN
CONJUNCTION WITH
MAJOR ITEM
General
List of Auxiliary Equip-
merit . . . . . . . . . . . . . . . . . . . . 4-1
Installation Instruc-
tions for Auxiliary
Equipment
Voice Security Equip-
ment Configuration . . . . . . . .4-2
Code Burst and CW
Configuration . . . . . . . . . . . . .4-3
Digital Message Device Group
OA-8990 Configuration . . . . . . . . 4-4
Handcrank Generator
Configuration . . . . . . . . . . . . . . . . .4-5
Power Supply Configuration . . . . . 4-6
Paragraph
Page
3-1
3-2
3-2
3-3
3-3
4-1
4-1
4-4
4-8
4-10
4-14
Appendix A.
Section I.
II.
Section I.
REFERENCES . . . . . . . . . . . . .
B.
COMPONENTS OF END
ITEM LIST . . . . . . . . . . . . . .
Introduction . . . . . . . . . . . . . . . .
Integral Components of
End Item . . . . . . . . . . . . . . . . .
ADDITIONAL AUTHORI-
C.
ZATION LIST
Introduction . . . . . . . . . . . . . . . .
Additional Authorization
II.
List . . . . . . . . . . . . . . . . . . . . .
A-1
B-1
B-3
C-1
C-2
Change 2 iii
TM 11-5820-553-10
Section
Number
1-1
1-2
2-1
2-2
2-3
2-4
2-5
4-1
4-2
4-3
4-4
4-5
4-6
D. EXPENDABLE SUPPLIES
AND MATERIALS LIST
I. Introduction . . . . . . . . . . . . . . . .
II. Expendable Supplies and
Material List . . . . . . . . .
. . . . .
Paragraph
Page
D-1
D-2
LIST OF ILLUSTRATIONS
Title
Radio Set AN/PRC-70 . . . . . . . . . . .
Contents of Accessory Carrying Bag . .
RT-1133/PRC-70 Controls.
Radio Set AN/PRC-70 Portable Con-
figuration . . . . . . . . . . . . . . . . . . . 2-6
Doublet Antenna AS-2975/PRC-70 . . . . . . . . . . . . 2-8
Long Wire Antenna Configuration . . . . . . . 2-11
Retransmit Configuration . . . . . . . . . . . . . . . . 2-13
Voice Security Equipment Configuration 4-2
CW Configuration . . . . . . . . . . . . 4-5
Digital Message Device Group (DMDG),
OA-8990/P Configuration . . . . 4-8
Handcrank Generator, G-76/G Con-
figuration, . . . . . . . . . . . . . . . . 4-10
Battery Charging with
Generator G-76/G . . . . . . . . . . . . . . . . . . 4-12
Power Supply, PP-6148/U Configuration 4-16
Handcrank
Page
1-4
1-5
2-2
iv
TM 11-5820-553-10/EE150-SN-OPl-010/E110-PRC 70
CHAPTER 1
INTRODUCTION
Section I. GENERAL
1-1. Scope
This manual contains operator instructions for Radio
Set AN/PRC-70. Equipment description, installation
instructions, and maintenance duties for the operator
are included in the manual. Operating and maintenance
instructions for the auxiliary equipment used with the
AN/PRC-70 are contained in separate technical
manuals. Refer to appendix A for a listing of these
manuals.
1-2. Consolidated Index of Army Publications and
Blank Forms
Refer to the latest issue of DA Pam 310-1 to determine
whether there are new editions, changes or additional
publications pertaining to the equipment.
1-3. Maintenance Forms, Records, and Reports
a. Reports of Maintenance and Unsatisfactory
Equipment. Department of the Army forms and pro-
cedures used for equipment maintenance will be those
prescribed by DA Pam 738-750, as contained in
Maintenance Management Update. Navy personnel will
report maintenance performed utilizing the
Maintenance Data Collection Subsystem (MDCS) IAW
OPNAVINST 4790.2, Vol 3 and unsatisfactory
material/conditions (UR submissions) IAW OP-
NAVINST 4790.2, Vol 2, chapter 17.
b. Report of Packaging and Handling Deficiencies.
Fill out and forward SF 364 (Report of Discrepancy
ROD)) as prescribed in AR 735-11-2/DLAR 4140.55/
NAVMATINST 4355.73B/AFR 400-54/MCO 4430.3H.
Change 2
1-1
TM 11-5820-553-10/EE150-SN-OPl-010/E110-PRC 70
c.
Discrepancy in Shipment Report (DISREP) (SF
361). Fill out and forward Discrepancy in Shipment
Report (DISREP) (SF 361) as prescribed in AR 55-38/
NAVSUPINST 4610.33C/AFR 75-18/MCO P4610
.19D/DLAR 4500.15.
1-4. Reporting Equipment Improvement
Recommendations (EIR)
a. Army. If your Radio Set AN/PRC-70 needs
improvement, let us know. Send us an EIR. You, the
user, are the only one who can tell us what you don’t
like about the design. Put it on an SF 368 (Quality
Deficiency Report). Mail it to Commander, US Army
Communications—Electronics Command and Fort
Monmouth, ATTN: AMSEL—PA—MA—D, Fort
Monmouth, New Jersey 07703—5000. We’ll send you
a reply.
b. Navy. Navy personnel are encouraged to submit
EIR's through their local Beneficial Suggestion Pro-
gram.
1-5. Warranty Information
Radio Set AN/PRC-70 is warranted by the contractor
for a period of 12 months. It starts on the date of
Government acceptance indicated on the appropriate
DD Form 2408-9. Report all defects in material or
workmanship to your supervisor who will take appropriate action through your Organization's maintenance shop.
Section II.
1-6. Equipment Characteristics, Capabilities and
Features (fig. 1-1)
Radio Set AN/PRC-70, referred to hereafter as the
radio set, is a medium-to-long-range communications
set which operates in the 2 to 76 MHz frequency band.
Various configurations of this equipment are possible so
that it may be transported by one or two persons or installed at fixed sites such as field headquarters, command
posts, etc. The radio set may be operated in all kinds of
1-2
Change 2
DESCRIPTION AND DATA
TM 11-5820-553-10
weather and terrain. Operating modes include
amplitude modulation (AM), single sideband (SSB),
continuous wave (CW), frequency modulation (FM),
and frequency-shift keying (FSK). Provisions are
included for the connection of separate security
devices to allow secure communications in selected
modes. Two radio sets may be connected together
for retransmission purposes.
1-7. Location and Description of Major
Components
The radio set consists of the items shown in figures
1-1 and 1-2. The items not described in separate
technical manuals are described in the following
subparagraphs.
1-3
TM 11-5820-553-10
1-4
Figure 1-1. Radio Set AN/PRC- 70.
Change 2
1-5
Figure 1-2.
TM 11-5820-553-10
Figure 1-2.
TM 11-5820-553-10
a. Receiver-Transmitter RT-1133/PRC-70. The
Receiver-Transmitter RT-1133/PRC-70 (A, fig.
1-1) is the major assembly of the radio set. Receiver-
Transmitter RT-1133/PRC-70 is referred to
hereafter as the RT unit. The RT unit is housed in a
metal case and contains the receive and transmit
circuits. Controls for the operator and cable connectors are located on the front panel of the RT unit.
b. Accessory Carrying Bag. The accessory
carrying bag (C, fig.1-1) is used for carrying the
following items (fig. 1-2):
(1) Handset H-250/U.
(2) Headset H-251/U.
(3) CW
CX-13101/PRC-70.
(4) Doublet Antenna AS-2975 PRC-70 con-
sisting of:
(a) 5-foot measuring tape.
(b) Ground rod.
(c) Balun assembly with RG-58 Cable
Assembly.
(d) 25-foot RG-25 Cable Assembly with BNC
adapter.
(e) Halyard assembly (2 each).
(f) Wire rope assembly (2 each).
(5) Whip Antenna AS-2974/PRC-70 consisting
of:
(a) 6-foot whip (4 sections).
(b) 9-foot whip (6 sections).
(c) Swivel antenna base.
c. Maintenance Cable Assembly. This assembly
(B, fig. 1-1) connects the RT unit to a power supply
for operating, testing, and troubleshooting the RT
unit without a battery.
d. Doublet Antenna AS-2975/PRC-70. This
assembly is a half-wave portable antenna that is
adjustable for an operating frequency between 2 and
30 MHz and is only used in fixed configurations.
Key KY-116/U
with Cable
1-6
TM 11-5820-553-10/EE150-SN-OPl-010/E110-PRC 70
e. Whip
assembly consists of a foldable 6-foot antenna, a
foldable 9-foot antenna, and a swivel antenna base.
The 6-foot antenna is used for the 4 to 76 MHz
range and the 9-foot antenna is used for the 3 to 76
MHz range. The whip antenna assembly is required
for portable configurations.
1-8. System Application
The radio set is a lightweight transceiver designed
for manpack use. It operates in the frequency range
of 2 to 76 MHz in AM, CW, SSB, and FSK modes
and from 30 to 76 MHz in FM mode. The radio set
has a long-range communications capability up to
2500 miles (4000 km). The 30 to 76 MHz SSB mode
offers flexibility for setting up communication nets
and links. The built-in antenna coupler is automatic,
and provides the best match with whip, long wire,
and doublet antenna assemblies.
1-9. Tabulated Data
The following subparagraphs describe the technical
data for the radio set. Table 1-1 lists the physical
data of the items of the radio set. The relationship
between the various modes, frequencies, antenna
assemblies and distances are shown in tables 1-2
and 1-3.
a. Receiver-Transmitter RT-1133/PRC-70
Input Voltage . . . . . . . . . . . . . . .+20 to +32 vdc
Power Consumption:
Receive Mode .. . . . . . . . . . . . 7 watts maximum
Low-Power Transmit Mode. . . .50 watts maximum
High-Power Transmit Mode
FSK, CW, FM, AM . . . . . . . . . . 160 watts maximum
SSB . . . . . . . . . . . . . 115 watts maximum
Power Output:
Duty Cycle . . . . . . . . . . . . . .9 to 1 receive-to-transmit
Antenna AS-2974/PRC-70. This
ratio.
Change 2
1-7
TM 11-5820-553-10
High-Power Mode
CW, FM*, FSK. . . . . . . . . . . 21-42 watts average
SSB . . . . . . . . . . . . . . . . . . . . . . .
AM . . . . . . . . . . . . . . . . . . . . . . . 7.5 watts carrier, 7.5
Low-Power Mode . . . . . . . . . .3 watts, +2dB, -2.5 dB
Frequency Range. . . . . . . . . . .2.000 to 75.9999 MHz in
* FM transmit enabled only in 30.0000 to 75.9999 MHz range.
NOTE
A temperature-sensing switch is located
in the power amplifier module. If continuous transmission at HI PWR is
required during high temperatures the
RT unit may switch to lower power
(approximately
proximately
operation. When the temperature is
sufficiently reduced the RT unit will
automatically return to the higher power
level.
Receiver Sensitivity:
FM . . . . . . . . . . . . . . . . . . . 0.60µV
SSB, FSK, CW . . . . . . . . . . . . . 0.375 to
AM . . . . . . . . . . . . . . . . . . . . . .2.50
Receiver Signal-to-Noise
Ratio . . . . . . . . . . . . . . . . . . . .10 dB at referenced
Receiver Selectivity:
FM . . . . . . . . . . . . . . . . . . . . . . . . . .32 kHz at 6dB
SSB, CW, FSK . . . . . . . . . . . . .2.8 kHz at 6 dB
AM. . . . . . . . . . . . . . . . . . . . 6.0 kHz at 6 dB
3 watts) after ap-
10 minutes of such
21-42 watts peak en-
velope power
watts upper sideband.
30 watts PEP at
85%
minimum
100 Hz steps
(varies with frequency)
modulation
0.50
µV
sensitivity
70 kHz at 60 dB
4.0 kHz at 26 dB
6.0 kHz at 60 dB
14.0 kHz at 60 dB
µV
1-8
TM 11-5820-553-10
Doublet Antenna AS-2975/PRC-70
b.
Frequency Range . . . . . . . . . . . . 2 to 30 MHz
(normal range)
Input Impedance. . . . . . . . . . . . 50 ohms
Whip Antenna AS-2974/PRC-70
c.
6- foot section . . . . . . . . . . . . . . 4 to 76 MHz
9-foot section . . . . . . . . . . . . . . .3 to 76 MHz
Table 1-1. Items Comprising an Operable Equipment
Dimensions
Length Depth Width Weight
NSN
Item
5820-01-062-8246 Radio Set
AN/PRC-70
Consisting
of:
5820-01-073-9114 Receiver-
Transmitter
RT-1133/
PRC-70
5995-01-092-5943 Maintenance
Cable
Assembly 1 60 –
Accessory
Carrying
Bag
5985-01-073-5602 Doublet
Antenna
AS-2975/
PRC-70
5985-01-073-5601 Whip An-
tenna
AS-2974/
PRC-70
(6 ft)
(9 ft)
5965-01-017-0549 Headset
H-251/U 1 8 4
5965-00-043-3463 Handset
H-250/U 1 8 2
5805-00-503-3395 CW Key KY-
116/U
with
(in.) (in.) (in.) (lb.)
Qty
4 11.9 13.25 21.0
1
1 11 17.5
1 2808 –
1
72 –
1 108 –
153
–
6.5
—
– 0.75
—
1.00
4
2
3
0.45
2.0
5.25
0.7
0.5
0.4
Change 2
1-9
TM 11-5820-553-10
Table 1-1. Items Comprising an Operable
NSN
5995-01-073-6123
Equipment- Continued
Length Depth Width Weight
(in.) (in.)
Item
Qty
Cable CX-
Dimensions
13101/
PRC-70
Ground Rod
SMC
746768/800-
45 NOTE 1 18 –
The following equipment is required but not supplied as part of the AN/PRC-70.
6140-01-089-7636 Battery
BB-542/U 1 12.2 2.56 4.0
Table 1-2. Operating Modes, Antennas, and Frequencies
Operating Mode
FM
Antenna Frequency
6-foot whip
30 to 76 MHz
9-foot whip 30 to 76 MHz
CW, FSK, AM, SSB
6-foot whip
9-foot whip
Doublet
4 to 76 MHz
3 to 76 MHz
2 to 30 MHz
(normal)
Table 1-3. Operating Modes, Antennas, and Distances
(in.) (lb.)
0.75
0.8
7.0
Mode
CW
Antenna
AS-2975/PRC-70
Distance Range
up to 2,500
miles*
SSB Voice, AM AS-2975/PRC-70 0–500 miles
SSB Voice, FM
AM
FM
AS-2974/PRC-70
AS-2974/PRC-70 0–15 miles
AS-2974/PRC-70
0–25 miles
0–15 miles
*Long wire antenna may be used (para 2-6b).
1-10
TM 11-5820-553-10
CHAPTER 2
OPERATING INSTRUCTIONS
Section I. CONTROLS
AND INDICATORS
2-1. Damage From Improper Settings
No damage will result to the equipment from improper control settings at turn-on. Battery life will
be shortened by some control settings. Maximum
battery drain occurs when the POWER switch is set
to HI PWR and the SQUELCH switch is held in the
DIAL LIGHT position. For best battery life use
other settings of the controls when possible.
2-2. Operator/Crew Controls
Figure 2-1 shows the RT unit front panel controls.
Table 2-1 lists the operator controls, indicators, and
connectors and describes their functions.
CAUTION
Do not change front panel controls while
RT unit is transmitting.
2-1
TM 11-5820-553-10
Figure 2-1.
2-2
Figure 2-1.
TM 11-5820-553-10
Table 2-1. Controls, Indicators and Connectors
Control, indicator,
or connector
Function
POWER switch Sets major functions of RT-l133/PRC-
70 as follows:
Positions:
OFF
RCV ONLY
LO PWR
Removes all power from RT unit.
Applies power to receive circuits only,
Allows transmission in low-power mode
when transmitter is keyed. Output is
approximately 3 watts,
HI PWR
Allows transmission in high-power mode
when transmitter is keyed. Output is
approximately 30 watts.
TUNE Starts automatic tuning sequence in unit
to tune antenna coupler. Switch is
spring loaded in this position and
returns to HI PWR position when
released.
MODE switch
Selects operating mode of unit. Modes
are CW, FSK, AM, SSB, and FM*.
* Transmit enables only in 30.0000 to 75.9999 MHz range.
VOLUME control
SQUELCH switch
Sets volume of received audio.
Controls operation of receiver squelch
and unit dial lights as follows:
Positions:
RXMT
Actuates switching circuit which con-
trols second RT-1133/PRC-70 in
retransmit mode.
OFF
ON
Disables squelch circuit.
Enables receiver squelch in voice modes.
Squelch is disabled if MODE switch is
set to CW or FSK.
DIAL LIGHT
Momentary switch position; applies
power to dial lights. Switch returns to
ON position when released.
RXMT connector
Connects
unit to second RT unit
RT-1133/PRC-70 in retransmit mode.
Connects CW Key KY-116/U for CW or
FSK operation.
AUDIO connector
Connects Handset H-250/U to RT unit
for normal voice operation and Headset
H-251/U during CW or FSK operation.
X-MODE
connector
Connects voice security applique to unit
for secure voice operation.
2-3
TM 11-5820-553-10
Table 2-1. Controls, Indicators and Connectors–Continued
Control. indicator
or connector
CAUTION
Dummy shorting caps for AN/PRC-70 and
AN/PRC-77 are not interchangeable.
NOTE
Shorting cap must be connected to connector at all
times when voice security applique is not being
used or power to RT unit will be interrupted.
ANT connector
Installing the coax connector of the doublet antenna to the antenna connector removes all R.F.
power from the wire connector post.
WHIP connector
Installing the antenna swivel base to the whip connector removes all R.F. power from the antenna and
wire connectors.
WIRE connector
GND connector
FREQUENCY
selector controls
and indicators:
A
B
C
D
E
F
Connects feedline for Doublet Antenna
AS-2975/PRC-70 to RT unit.
NOTE
Connects whip Antenna AS-2974/PRC-70 to
RT unit.
NOTE
Connects random wire length antennas to
RT unit.
Connects ground wire to RT unit.
Operating frequency is changed by rotat-
ing frequency selector controls while
observing frequency readout numerals.
FM transmit is disabled by these
controls below 30.0000 MHz setting.
Megahertz tens selector
Megahertz unit selector
Kilohertz hundreds selector
Kilohertz tens selector
Kilohertz units selector
Hertz hundreds selector
Function
2-4
Change 2
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