Rockwell Automation COLLINS MP-20 User manual

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Introduction-----------------------------------------------------------------------------------------3
Radio Set Components----------------------------------------------------------------------------4
Operating Configurations andOptions--------------------------------------------------------9
Standard Two-Person Configuration----------------------------------------------------------9
Single Operator Configuration------------------------------------------------------------------9
Cold Weather Configuration-------------------------------------------------------------------10
Audio/Keying Option---------------------------------------------------------------------------- 10
Input Power Option------------------------------------------------------------------------------10
Antenna Options----------------------------------------------------------------------------------10
Preparation For Use------------------------------------------------------------------------------11
963A-1 Radio Set Harness---------------------------------------------------------------------- 11
719D-2A Receiver-Transmitter Group------------------------------------------------------ 13
Power Pack---------------------------------------------------------------------------------------- 14
Headset, Handset and Telegraph Key------------------------------------------------------- 14
938A-2 Antenna---------------------------------------------------------------------------------- 14
Antenna Counterpoise-------------------------------------------------------------------------- 15
938A-1 Antenna-Vertical Orientation------------------------------------------------------- 16
938A-1 Antenna-Horizontal Orientation--------------------------------------------------- 17
Operation----------------------------------------------------------------------------------------- 19
Preliminary Setup For Mobile Use----------------------------------------------------------19
Preliminary Setup For Stationary Use----------------------------------------------------- 20
886B-1 Generator Operations-------------------------------------------------------------- -20
Spare Battery Use------------------------------------------------------------------------------ 21
719D-2A Receiver-Transmitter Group Operating Controls---------------------------21
Frequency Display and Selectors---------------------------------------------------21
Mode Selector--------------------------------------------------------------------------21
Function Selector----------------------------------------------------------------------21
Gain Control---------------------------------------------------------------------------22
Panel Lighting-------------------------------------------------------------------------23
Operating Indicators------------------------------------------------------------------------- 23
Operating Time--------------------------------------------------------------------------------23
Warnings--------------------------------------------------------------------------------------- 23
Voice Communication----------------------------------------------------------------------- 24
CW Communication------------------------------------------------------------------------- 24
Data Communication------------------------------------------------------------------------ 24
Operation Maintenance---------------------------------------------------------------------25
Clearing Tune-Incomplete Condition---------------------------------------------------25
Reenergizing The 612A-1 Battery--------------------------------------------------------25

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Introduction
The MP-20 Radio Set (figure 1 is a lightweight HF portable receiver – transmitter
which offer many desirable features.
Figure 1. MP-20 Radio Set.
■20 watts of RF power output (pep or average)
■280,000 communications channels in the 2- to 30-MHz band at 100-Hz increments
■SSB and AM operation
■Voice, CW and data modulation
■Rugged construction
■Much smaller size and lighter weight then older systems
■Fully waterproof
■Low power consumption
■An integrated, automatic antenna tuner with constant VSWR surveillance for
greater efficiency.

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MP-20 radio set components
The MP-20 Radio Set, shown in figure 2, consists of the 719D-2A Receiver
Transmitter Group, 612A-1 Battery, 963A-l Radio Set Harness, H-189/GR Handset,
and 938A-2 Antenna.
Figure 2. MP-20 Radio Set Components

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7191D-2A receiver-transmitter group
A compact lightweight receiver - transmitter consisting of three units: 377L-2
Receiver – Transmitter Control, 671V-2 Receiver – Transmitter, and a 549A-2
Amplifier-Coupler. When mechanically latched together, these units are electrically
connected through mating connectors. All operating controls for the receiver-
transmitter are located beneath a hinged cover on the 377L-2.
612A-1 battery
A Nickel cadmium, 1.8 Ah, battery that latches beneath the 719D-2A Transmitter –
Receiver Group. It supplies DC power to the receiver – transmitter for 12 hours of
operation at a 1:9 transmits voice/receive duty cycle.
963A-1 radio set harness
A Lightweight, rugged pack frame with adjustable straps. It can hold,
simultaneously, a 719D-1A Receiver-Transmitter Group, 612A-1 Battery, and either
an 886B-I Generator or a spare 612A-1 Battery. The field pack attaches to the rear
of the pack frame, and has compartments to store all the accessory components
except the 412Y-2 Battery Charger.
H-189/GR handset.
A Handset with an earpiece, microphone, and push-to-talk (ptt) switch in one
assembly. It is connected to the receiver-transmitter through a coiled cord and plug.
938A-2 antenna
A 2.4 meters (8-foot) whip antenna that can be easily folded for storage. It has a
shock absorbing mount and detent positioning device capable of ±90" front-to-back
movement in 45o increments.
MP-20 accessory components
Accessory components, shown in figure 3. that may be used with the MP-20 include
headset, telegraph key, 540L-1 Battery Cable, 938A-1 Antenna, antenna
counterpoise, 540K-1 Control Extender, 412Y-2 Battery Charger, 886B-1
Generator, and nonrechargeable battery.

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Figure 3. Accessories Components (Sheet 1).

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Headset
A headset consisting of two earpieces, a boom microphone, a push to talk (ptt)
switch, a headband, and a coiled cord and plug.
Telegraph key
The telegraph key is adjustable in tension and gap, and has a 0.9-metre (3-foot)
flexible cord and plug. The key can be attached to the operator's thigh with a strap.
540L-1 battery cable
A 1.5-metre (5-foot) cable and a canvas bag, with an adjustable shoulder strap, that
allows the 612A-1 Battery to be carried under the operator’s outer clothing during
very cold weather.
938A-1 antenna
A dipole antenna that consists of two 35.67-metre (117-foot) braided wires wrapped
on individual plastic bobbins, that allow long-range communication. Each wire has
a 15.25-metre (50-foot) throwing line attached. The two wires are connected to a
center junction, which is connected to the receiver - transmitter with a 15.25-metre
(50-foot) antenna feeder cable.
Antenna counterpoise
Four 10-metre (32.8-foot) braided wires, wrapped on a plastic bobbin, are used to
provide a ground plane in low electrical conductivity areas. The four wires are
connected together at a center junction, which is connected to the receiver-
transmitter with a 1.8-metre (6-foot) cable.
510K-1 control extender
A 2-piece unit that allows the 377L-2 Receiver-Transmitter Control to be extended
for one-man operation of the receiver-transmitter while it is mounted on the
operator's back. The 377L-2 plugs into the part that clips onto the operator's belt.
The other part, connected through a cable, secures to the 671V-2 Receiver-
Transmitter.

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Figure 3. Accessories (Sheet 2).

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412Y-2 battery charger
A portable battery charger, with a cover, that allows up to six 612A-1 Batteries to be
charged or discharged simultaneously. It operates with either +28 volts dc power or
110 volts ac power. A simple internal wiring change permits Operation on 220-V ac
power.
886B-1 generator
A hand-operated generator that can be latched between the receiver-transmitter
and the battery to extend the operating time indefinitely. The charging current is
about 125 mA at cranking speeds that can be maintained by the operator for 15
minutes.
Nonrechargeable battery
The nonreehargeable battery is a dry expendable battery that can directly replace
the 612A-1 Battery.
Operating configurations and options
The accessory components may be used with the 719D-2A Receiver-Transmitter
Group to produce operating configurations for various missions. Options that must
be considered in selecting the proper configuration include: type of input power,
mission duration, transmission range, stationary or mobile use, one or two man
operation and weather conditions.
Standard two-person configuration
The standard configuration consists of the 719D-2A Receiver-Transmitter Group
and 612A-1 Battery installed in the 963A-l Radio Set Harness. The 938A-2 Antenna
is connected to the antenna connector and the H-189/GR Handset is connected to an
audio connector. This configuration may be used during mobile missions of up to 12
hours operating time and distances up to 25 kilometers (15.5 miles). Normally, two
persons are required; one to carry the unit, the other to operate the controls from
the rear.
Single operator configuration
The 377L-2 Receiver-Transmitter Control can he clipped onto the operator's belt
using the 540K-1 Control Extender. This makes it possible for one person to operate
the 719D-2A Receiver-Transmitter Group while carrying it.

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Cold weather configuration
During very cold weather, the 612A-1 Battery must be kept warm to obtain
sufficient mission time. The 540L-1 Battery Cable allows the 612A-1 Battery to be
removed from the 963A-1 Radio Set Harness and to be carried in a battery bag
under the operator's outer clothing.
Audio/keying option
The 719D-2A Receiver-Transmitter Group can be keyed by the H-189/GR Handset,
the headset, the telegraph key, or by a modem. All connections are made to one of
the two audio connectors on the 377L-2 Receiver-Transmitter Control.
Input power option
The 963A-1 Radio Set Harness is made to accept a second 612A-1 Battery, which is
latched beneath the operating 612A-l Battery. When the operating G12A-1 Battery
becomes discharged, it can be interchanged with the spare 612A-l Battery to provide
a total of 24 hours of operation.
For cases of isolated or extended missions, when recharged 612A-1 Batteries are not
available, the 886B-1 Generator is used to replenish the battery charge. It may be
used either when the 719D-2A Receiver-Transmitter Group is not being used or
when it is in operation. The 886B-1 Generator connects directly between the 719D-
2A Receiver-Transmitter Group and 612A-1 Battery on the 963A-l Radio Set
Harness, without the need for additional cables.
Antenna option
In dry or rocky terrain of low electrical conductivity, a counterpoise Is provided for
use with the whip antenna. The simple 4-wire counterpoise is laid out on the ground
and its center connected to the shell of the BNC connector on the 719D-2A Receiver-
Transmitter Group.
To accomplish extended range communications, a simple portable 93SA-1 Antenna
(dipole) is provided for use in place of the 2.4-metre (8-foot) whip antenna. Each leg
of the dipole has a nylon throw line for stringing the dipole between convenient trees
or other structures. The center of the dipole has a coaxial feed cable, which is
connected to the BNC connector on the 719D-2A Receiver-Transmitter Group. The
dipole may be erected either vertically or horizontally; horizontal erection
providing, the greater range.
A 637K-1 Antenna can be used with the 719D-2A Receiver-Transmitter Group. This
high-angle radiation antenna requires a base adapter.

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Preparation for use
Make sure the contents of Operating Configurations and Options is understood
before proceeding with the Preparation for Use procedures.
963A-1 radio set harness
A. Remove pack frame, field pack, and straps from shipping container
B. Place nylon backrest over top and bottom horizontal tubular parts of pack frame.
Refer to figure 4. The 3-tab end of backrest goes on top. Lace nylon string between
eyelets on top and bottom of backrest and tie securely. Strings should be on the
inward side of the pack frame
Figure 4. Attaching Backrest to Pack Frame
C. Slide lower backstrap through slots on pack frame and connect turnbuckle to
both ends of lower backstrap. Refer to figure 5. Tighten turnbuckle. This adjustable
lower backstrap keeps the load away from the carrier's back and allows air
circulation between the back and the load. When the turnbuckle is screwed tight,
the strap is almost flat. If the carrier's waist is small, the turnbuckle should be
loosened enough to allow the backstrap to curve in and fit against the lower back.
Figure 5. Attaching Lower Backstrap to Pack Frame

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D. The two padded shoulder straps are attached to the pack frame at the top and
bottom. Refer to figure 6. The shoulder strap with the quick release assembly is for
the left shoulder. Insert the looped (lower) end of the shoulder strap from the inside
of the pack frame through the opening at the bottom side (just below the slot that
accepts the lower backstrap). Thread the strap trough the loop and pull tight. Route
the webbing at the top of the strap around the top of the frame (between the tabs of
the nylon backrest) trough the buckle and pull tight. Repeat the procedure with the
other shoulder strap.
E. The waist strap has a quick release assembly like the left shoulder strap. The part
of the waist strap with the pull-tab should be attached on the left or right of frame,
depending on which hand is used to pull it open. Insert the looped end of the strap
from the outside of the pack frame trough the opening on the lower part of the
frame. Thread the strap trough the loop and pull tight. Repeat the procedure with
the other waist strap.
Figure 6. Attaching Shoulder and Waist Straps to Pack Frame

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F. The field pack is attained to the rear and bottom of the pack frame. Refer to
Figure 7. Place the metal rings, on rear of field pack, over the two hooks on the rear
of the pack frame. Insert the webbing straps, on the field pack, through the
openings near the hooks, through the buckles, and pull tight. Secure the bottom
straps on the field pack through the openings on the bottom of the frame, and pull
tight.
Figure 7. Attaching Field Pack to Pack Frame
719D-2A receiver-transmitter group
To prepare Receiver – Transmitter for operation, proceed as follows.
A. Secure either the 377L-2 Receiver-Transmitter Control or the 540K-1 Control
Extender to the 671V-2 Receiver-Transmitter using four screws. Ensure that their
mating connectors are aligned and mated before tightening the screws.
B. Secure the 548A-2 Amplifier-Coupler to the 671 V-2 Receiver Transmitter using
the four latches: two on the bottom, an adjustable one in front, and an adjustable
one in rear. Ensure that their mating connectors are aligned and mated before
engaging the latches.
C. Slide assembled 719D-2A Receiver-Transmitter Group into the 963A-1 Radio Set
Harness from the top. Secure receiver-transmitter to pack frame by engaging and
tightening the four spring-1oaded cam latches, two on each side.

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Power pack
The power pack for the 719D-2A Receiver – Transmitter Group is the 612A-1
Battery; either by itself, or with a spare battery, or with an extender cable or with a
hand crank generator.
CAUTION
Do not short circuit battery as permanent damage can occur.
A. If only the 612A-1 Battery is to be used, slide it into the pack frame, from the
side, beneath the 719D-2A Receiver-Transmitter Group. Mate the electrical
connectors and secure the battery to the Receiver – Transmitter using the two
latches.
B. If the 612A-1 Battery is to be used with a spare battery, secure them together
with the two latches on the spare battery. Then slide the combination into the pack
frame, from the side, beneath the 719D-2A Receiver-Transmitter Group. Male the
electrical connectors and secure the top battery to the receiver-transmitter using the
two latches. Secure the bottom battery to the pack frame with two thumbscrews.
C. If the 612A-1 Battery is to be used with the 886B-1 Generator, place the
generator on top of the battery and secure them together with the two latches on the
battery. Then slide the combination into the pack frame from the right side, beneath
the 719D-2A Receiver – Transmitter group. Mate the electrical connectors and
secure the generator to the receiver – transmitter using the two latches. Secure the
battery to the pack frame with two thumbscrews. Position hand crank so that it
rests in the bracket on the pack frame; and secure by rotating the hand crank
holding catch.
D. If the G12A-1 Battery is to be used with the 540L-1 Battery Cable, plug one end
of the cable into the bottom connector of the 712D-2A Receiver - Transmitter
Group, or 886B-1 Generator if used and tighten the thumbscrews. Place battery into
battery bag.
Headset, handset and telegraph key
Plug the connector(s) of the handset, or headset, or telegraph key, or a combination
of them into the audio connector(s) on the 377L-2 Receiver – Transmitter Control.
938A-2 antenna
A. Unfold the sectional whip antenna, and engage each section to its adjacent section
B. Fit the plug of the antenna mount onto the whip antenna connector on the 549A-2
Amplifier-Coupler, tighten holding nut firmly to ensure antenna switch operation.

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Antenna counterpoise
A. Unwind the four 10-metre (32.8 foot) braided wires of the counterpoise of the
plastic bobbin.
B. Stretch four wires in four directions and secure looped ends over stakes pounded
in the ground. Refer to figure 8.
C. Place receiver – transmitter with whip antenna near center of counterpoise.
D. Connect the 1.8-metre (6-foot) cable from the counterpoise center junction to the
BNC connector on the 549A-2 Amplifier-Coupler.
E. Position whip antenna in a vertical position by pulling up handle on antenna
mount and then releasing into correct detent.
Figure 8. Counterpoise Placement.

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938A-1 antenna-vertical orientation
A. Unwind the support throw lines and enough antenna wire from each bobbin, for
the frequency in use. Markings on the antenna wire are provided to simplify this
operation. Connect the ends to the dipole center junction terminals as shown in
figure 9. Connect snap fasteners to provide strain relief.
Figure 9. Center Junction of 938A-1 Antenna
NOTE:
In some cases, better transmission is obtained if the operating frequency is three or
five times the frequency at which the antenna is set.
B. Make a small loop in the antenna wire at the measured point. Insert it into the
hole on the bobbin terminal and secure the wire by tightening the thumbscrew,
Refer to figure 10, Repeat for the other half of the antenna.
Figure 10. 938A-1 Antenna Securing
C. Connect the plug on the 15.25-metre (50-foot) antenna feeder cable to the socket

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of the dipole center junction and connect the snap fastener to the anchor ring.
Connect the other end of the feeder cable to the BNC connector on the 549A-2
Amplifier-Coupler.
D. Erect the antenna with the wire as close as possible to the vertical position as
conditions allow. Refer to figure 11.
Figure 11. Vertical Orientation of 938A-1 Antenna
E. Ensure that the antenna feeder cable is well separated from the antenna wire
and, ideally, should be positioned at right angles to the wire.

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938A-1 antenna - horizontal orientation
A. Unwind the support throw lines and enough antenna wire from, each bobbin for
the frequency in use. Markings on the antenna wire are provided to simplify this
operation. Connect the ends to the dipole center junction terminals as shown in
figure 9. Connect snap fasteners to provide strain relif.
NOTE:
In some cases, better transmission is obtained if the operating frequency is three or
five times the frequency at which the antenna is set.
B. Make a small loop in the antenna wire at the measured point. Insert it into the
hole on the bobbin terminal and secure the wire by tightening the
thumbscrew. Refer to figure 10. Repeat for the other half of the antenna.
C. Connect the plug on the 15.25-metre (50-foot) antenna feeder cable to the socket
of the dipole center junction and connect the snap fastener to the anchor ring.
Connect the other end of the feeder cable to the BNC connector on the 549A-2
Amplifier-Coupler.
D. Orient t.ho antenna so that the direction of reception and transmission is along a
line at right angles to the line of the antenna.
E. Erect the antenna with the wire as high as possible. A minimum height of 1/4 λ(λ
is wavelength in meters) is recommended. Also, erect the antenna as close as
possible to the horizontal position between two supports as shown in figure 12.
Figure 12. Horizontal Orientation of 938A-1 Antenna
F. Ensure that the antenna feeder cable is well separated from the antenna wire and,
ideally, should be positioned at right angles to the wire.

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Operation
Perform the procedures described in Preparation for Use before proceeding with
either of the following preliminary setup procedures.
CAUTION
Do not operate the radio set without a suitable antenna. Make sure the antenna is
properly connected before tuning the radio set.
Preliminary setup for mobile use
A. Using shoulder straps and waist strap, secure assembled radio set to back of
carrier. Both the left shoulder strap and the waist strap have quick release
assemblies, which should be secure as shown in figure 13. Adjust shoulder straps,
waist strap, and lower backstrap for maximum comfort.
Figure 13. Shoulder Strap and Waist Strap Quick Releases
B. Position whip antenna in a vertical position by pulling up antenna mount and
then releasing in correct detent.
C. If the 540K-1 Control Extender is being used, loop over the shoulder and clip it
onto the belt of the operator.
D. If the 540L-1 Battery Cable is being used, place the battery bag over the shoulder
and strap it around the thigh of the operator, under the outer garments. Plug the
battery end of the cable into the battery connector and tighten the thumbscrew.
E. If the telegraph key is being used, strap the key to the thigh. Plug cable into
connector on 377L-2 Receiver-Transmitter Control. Adjust key gap and tension as
desired

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F. If the H-1S9/GR Handset is being used, plug cable into connector un 377L-2
Receiver-Transmitter Control. Hook handset onto hook on right shoulder strap.
G. If headset is being used, place headset around operator's head with earphones
over ears and metal connecting bar behind neck. Loop Velcro head strap over head
and connect together. Loosen knurled knob and adjust microphone to a position
directly in front of mouth; then tighten knob. Clip psah-to-talk switch (ptt) to
clothing on chest. Plug cable into connector on 377L-2 Receiver – Transmitter
Control
Preliminary setup for stationary use
A. Lay assembled radio set on ground, either on its front or rear.
B. The radio set is normally operated with the standard whip antenna, which is
generally satisfactory for distances up to 25 kilometres (15.5 miles). In dry or rocky
terrain of low electrical conductivity, use the counterpoise with the whip antenna.
Where greater distances are required, the dipole antenna should be used, and
should be erected as close to the vertical as conditions allow. For considerably
greater distances, the dipole should be erected horizontally between two supports,
and its line should be at 900to the direction of the distant station. Select the desired
antenna and install it as directed in preparation for use.
C. If the 540L-1 Battery Cable is being used, place the battery bag over the shoulder
and strap it around the thigh of the operator, under the outer garments.
D. If the telegraph key is being used, strap the key to the thigh of the operator. Plug
cable into connector on 377L-2 Receiver - Transmitter Control. Adjust key gap and
tension as desired.
E. If the H-189/GH Handset is being used, plug cable into connector on 377L-2
Receiver - Transmitter Control.
F. If headset is being used, place headset around operator's head with earphones
over ears and metal connecting bar behind neck. Loop Velcro head strap overhead
and connect together. Loosen knurled knob and adjust microphone to a position
directly in front of mouth, then tighten knob. Clip push-to-talk switch (pit) to
clothing on chest. Plug cable into connector on 377L-2 Receiver – Transmitter
Control.
886B-1 generator operation
When the charge on a battery is too low to provide adequate power for receiver-
transmitter operation, a clicking sound will be heard on the headset or handset
earpiece. The battery charge can be replenished in the field using the hand-crank
generator.
Recharging the battery can be accomplished with the receiver-transmitter turned
off or while it is being operated. To recharge the battery, rotate the hand crank
clockwise. Adequate charging current is generated when the green light on the
hand-crank generator is lit. During normal operation, the red light should remain
off. In normal operation, the operator will not become prematurely fatigued.