The MA-4450 was a Message Entry and Read-Out Device (MEROD) developed
by Racal COMSEC in Salisbury (UK).
It was intended for sending encrypted messages in
burst mode over a radio link,
and was therefore often used by Special Forces (SF) in combination with a
manpack radio.
The image on the right shows a typical MA-4450 with the optional
illumination lid opened.
It has a large LCD screen at the top
and a keyboard with 51 rubber keys below it. The keyboard consists of the
usual alphanumerical keys (0-9 and A-Z) with the common QWERTY layout.
At the top row are 7 function keys, the rightmost of which is the OFF key.
At the bottom are the space bar and two large keys for left
and right.
The MA-4450 is also known as a Tactical Data-Entry Device(TDED)
or by its National Stock Number (NSN) 5811-99-722-5579.
All connections are at the rear of the unit.
There are 4 sockets for RADIO, HANDSET, PRINTER and a REMOTE port.
Each socket accepts a different type of connector, so that mistakes are
avoided. Power is supplied to the MA-4450 via the REM-PORT.
When the optional illumination lid is fitted, it takes its power from the
PRINTER socket, to which it is connected by means of a short lead.
For use in the field, and in particular by special forces, the MEROD would
generally be packed inside a nylon 'raincoat' or carrying pouch,
such as the one shown in the image on the right.
It allows the device to be carried at the shoulder or
to be attached to the webbing.
The MEROD can be operated from within the pouch that has various pockets
for the ancillaries, cables and the junction box. Further images below.
A small junction box is used to connect the
device (TDED) to the radio and a suitable DC power source. This junction
box is known as the Rapier Interface Box (RIB). It has the designator MA-4271
and can be installed in one of the pockets
of the pouch.
A special version of the MEROD was made for the US Special Forces. It is
designated KY-879/P
and is also known as NSN 5820-001-100-3194.
During the 1980s MEROD devices, such as the MA-4450, were used by Dutch
Special Forces (104 Waarnemings- en Verkenningscompagnie) for operations
behind enemy lines, in many cases combined with a
manpack radio set,
such as the
AEG Telefunken SE-6861 (Dutch: LAPR).
The image on the right [1] shows Dutch Special Forces (Commando's) using a
MEROD device in an underground hideout. At the top right is the
SE-6861 radio set.
In the Netherlands this radio was commonly known as LAPR which is short for
Lange Afstands Ploeg Radio (Long Distance Group Radio) or by
designator KL/TRC-5151.
The MEROD itself was known in The Netherlands as
Digitaal Berichten Apparaat or DBA (Digital Message Device).
It was also used at the
other end of the link, e.g. in the (mobile)
command center
shown in the second image below[1].
MEROD was also used in combination with the
MA-4420 MEROD base station, which
allowed messages to be (pre)recorded, stored and
printed. It could also be controlled by a computer.
Below is an overview of the various parts that are used in combination
with the MEROD. The first section of the table lists the parts and cables
that were supplied with our unit. The lower section list the cables
that were available [B]. If you know of any other ancillaries,
please let us know.
Name
Description
Designator
NSN
MEROD
Message entry device
MA 4450
5811-99-722-5579
RIB
Rapier Interface Box
MA 4271
5811-99-786-8876
BCPP
2m cable 7-pin male to 50 pin Centronics
BA 453840
5811-99-786-8879
HANDSET
10 cm cable 7-pin male to 7-pin female
BA 454625
-
TDED
30 cm cable 7-pin male to 7-pin male
BA 453848
5811-99-786-8886
DC SUPPLY
Cable 4-pin female to 3-pin male
BA 453844
5811-99-786-8882
RADIO
Cable 7-pin male to 7-pin male
BA 454624
-
The following cables are listed in the manual [B]:
BCPP
2m RIB SKA to Computer
BA 453840
5811-99-786-8879
RADIO
2m TDED SKD to CNR or CUR
BA 453841
-
RADIO
6m TDED SKD to CNR
BA 453842
-
DC SUPPLY
2m RIB PLG (PSU input) to PSU
BA 453844
5811-99-786-8882
DC SUPPLY
6m RIB PLG (same as above)
BA 453845
-
DC SUPPLY
1m RIB PLG to vehicle battery
BA 453846
-
DC SUPPLY
Y-cable 453844 to CUR heated-glove socket
BA 453847
-
TDED
40cm RIB SKL to TDED REM-PORT
BA 453848
5811-99-786-8886
DC SUPPLY
1m RIB PLG to EDED Standby Pack
BA 453856
-
Glossary
BCPP
Battery Command Post Processor
Tactical planning, deployment and management computer system.
CNR
Clansman Radio
The MA-4450 MEROD was initially designed for use with the British
Clansman series of military radios.
With an appropriate adapter cable it can also be used with other radios.
CUR
Communications Unit Rapier
RIB
Rapier Interface Box
A small junction box (MA-4271) that is connected to the REM-PORT (Remote Port)
of the of the MEROD. It has two sockets (TDED and BCPP) that are connected
in parallel and a smaller PSU socket. It allows the MEROD to be connected
to a power source and a computer/peripheral simultaneously.
TDED
Tactical Data-Entry Device
The is the actual MEROD or MA-4450 device.
PSU
Power Supply Unit (e.g. vehicle battery)
External power source for the TDED, which can be a CUR, a branch cable
(Y-cable), vehicle battery, external PSU or TDED Standby Pack.
Connections
The diagram below shows how the various parts are connected via
the supplied cables. Basically, the MEROD is connected in between
the radio and the handset. A short optional extension cable of approx.
10 - 20 cm (BA 454625) may be used for easier connection of the handset,
whilst a long cable (BA 454624) connects the MA-4450 to the radio.
If the optional illuminated top lid is present, it should be connected
to the PRINTER socket (SKB) of the MEROD as shown here:
The Rapier Interface Box (RIB) is connected to the Remote Port (REM-PORT)
of the MEROD. It bascially expands the REM-PORT into two identical ports
(TDED and BCPP) and allowed an external power source to be connected
simultaneously to the DC SUPPLY socket at the right.
