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Selex EZPRR   H-174-4855-ELSA
Enhanced Encrypted Personal Role Radio

EZPRR is a short range Personal Role Radio (PRR) for military use, developed by Selex ES 1 in the UK in 2005. It is the successor to the PRR (H4855) and offers extended range, data transmission and full voice/data AES128 encryption. The radio is typically used by Special Forces (SF) units, reconnaissance squads and infantry sections for direct tactical soldier-to-soldier communication. EZPRR is sometimes written as EZ-PRR. The radio is also known as H-174-4855-ELSA.

The radio operates in the 2.4 GHz band and uses spread spectrum technology. It weights 1.5 kg and is powered by two 1.5V AA-size penlight batteries, allowing 20 hours of continuous use.

It is a low-power device with a range of approx. 800 m, and works well through the thick walls of a building. The EZPRR is used by all British Forces, some US forces and even by UN peace keeping forces. The device is typically issued to every member of an eight-person infantry section. A separate wireless Push-To-Talk (PTT) unit with a 2m range is available as an option.

The device offers 256 communication channels, 16 of of which can be selected directly via the channel selector. Only channels 1 to 14 can be encrypted. Channels 15 and 16 operate 'in clear' in order to provide backwards compatibility with the earlier unencrypted Selex PRR radios. A small hidden rotary switch further allows 16 of such 16-channel banks to be selected.

  1. Selex ES was formerly known as Selex Communications and before that as Selenia Communications and as Marconi. On 28 march 2016, the company was renamed Leonardo, after its parent company.

EZ-PRR EZ-PRR with enhanced antenna Controls and connections Thales GPS receiver connected to the EZPRR EZPRR and GPS unit in the same pouch EZPRR with bended gooseneck antenna Racal Frontier SF headset With and without gooseneck
The diagram below gives a quick overview of the controls and features of the EZPRR. The device has the same form factor and controls as its predecessor, the PRR. A removable switch pack is attached at its right side and allows it to be configured for different applications. It is shown here with the standard single-PTT switch pack. The enhanced antenna offers a better gain and, hence, an increased range. Furthermore, the HF output has been increased from 50 mW to 100 mW.

A suitable headset should be connected to the headset socket at the top. Transmission is operated by pressing the PTT button at the side of the radio, or by means of an (optional) external wireless PTT. The set can be enhanced in several ways, for example by swapping the switch pack for a dual-role one, adding a GPS receiver, or using a Special Forces (SF) headset.

The diagram above shows a Selex EZPRR with the optional Thales GPS receiver. It is connected to the data socket of the EZPRR and should be located at the side of the radio. Special carrying pounches are available that can bold both devices. Frequencies and cryptographic keys are programmed by means of a PC with special software that is connected to the headset socket.

Standard headset with one speaker and boom-type microphone Racal Frontier Special Forces headset
GPS locator beacon
Single PTT switch pack Dual PTT switch pack Carrying pouch Enhanced antenna Gooseneck antenna
Remote PTT Programming and key filling cable
Patrol Headset
A simple lightweight headset is supplied with every PRR. It has a very short cable and connects directly to the headset socket on the PRR.

The headset consists of a single earpiece with an adjustable gooseneck noise-cancelling microphone mounted at the bottom. Elastic straps are used to fixate the headset on the operator's head. At the end of the short cable is a black LEMO connector that mates with the headset socket on the PRR.

Frontier SF headset
As an alternative to the standard headset shown above, special in-ear headsets were available, such as the Racal Frontier set shown here. These headsets are particularly popular with Special Forces (SF) and provide hearing protection as well as 'talk-through', so that the operator can still hear the surrounding sound.   
Racal Frontier SF headset

GPS beacon
The EZPRR can be enhanced by connecting an external GPS receiver to its data socket. The image on the right shows the Thales GPS receiver (or Navigation Module as it is called) that was developed especially for this purpose.

It is fully compatible with the Infantry Soldier Situational Awareness Tool (ISSAT) and allows somewone with an ISSAT terminal to see the current position of each platoon member [2]. In case of a casualty, the soldier can pull the orange plug in order to send a distress signal.
Thales GPS receiver connected to the EZPRR

Thales GPS receiver connected to the EZPRR Thales GPS receiver Open battery compartment Distress plug Removed distress plug Thales GPS receiver connected to the EZPRR EZPRR and GPS unit in the same pouch
Single PTT switch pack
By default, each EZPRR comes with the single PTT switch pack shown here. It has a connection for the headset at the top and a socket for connection of the optional GPS locator at the bottom. The PTT is at the side. The switch pack is mounted to the radio by means of one bolt.   
Single PTT switch pack

Dual PTT switch pack
As an option, the switchpack of the EZPRR can be swapped for a version with two PTT buttons, allowing an external radio to be controlled directly from the EZPRR's headset.

The dual PTT option has a fixed cable with a connector at the end, for connection to the external radio. The one shown here was made for the Clansman series radios, but other types are available as well.
Dual PTT switch pack

Single PTT switch pack Inner contacts of the Single PTT switch pack Headset socket on the single PTT switch pack Data socket at the bottom of the single PTT switch pack Switchpack separated from the EZPRR Dual PTT switch pack Dual PTT switch pack mounted to the EZPRR Close-up of the two PTTs. The circular one is the 2nd PTT. It is somewhat recessed.
Carry pouch
Various carrying pouches are available, such as the one shown here. It has camouflage colours and can be attached to the soldier's webbing kit. The one shown here also has room for the optional GPS locator.   
EZPRR and GPS unit in the same pouch

Enhanced antenna
In order to extend the range of the EZPRR compared to the older PRR, a longer antenna with a better gain is used. Together with the enhanced power ouput, this effectively doubles the radio's operational range.

The antenna can be mounted directly to the antenna socket of the radio, but can also be mounted on top of the goosenex extension.
EZ-PRR with enhanced antenna

Gooseneck antenna
For special field requirements, in particular for use by Special Forces (SF), a gooseneck option for the antenna was developed. It is fitted between the radio and the enhanced antenna and allows the antenna to be positioned independantly from the radio.   
Bended gooseneck antenna

With and without gooseneck Gooseneck mounted to the EZPRR Gooseneck socket (left) and antenna (right) Antenna mounted on top of the gooseneck EZPRR with gooseneck antenna Operating the EZPRR with gooseneck antenna EZPRR with bended gooseneck antenna Bended gooseneck antenna
Wireless PTT
The transmitter of the EZPRR can be activated by pressing the PTT at the side of the device, but also by means of an (optional) external wireless PTT. This wireless PTT has to be paired with the radio and is different from the one used with the older PRR.

Currently unavailable.
This image shows the Remote PTT of the older PRR. We are currently looking for a Remote PTT for the EZPRR.

Programming cable
Both the featues and the cryptographic keys of the EZPRR can be programmed by means of PC-based software. For connection of the PC, this special programming cable is needed.

One end is connected to the headset socket of the EZPRR, whilst the other end goes to the serial port (RS232) of a PC or laptop. If no serial port is available, a suitable USB-adapter is required.

As present, we don't have the software for this. If you can provide it, please contact us.
Programming cable

The EZPRR has two sockets for connection of the ancillaries. The one at the top is for connection of a headset. The one at the bottom is the data socket, which is used for connection of the GPS receiver. The order of the connector pins is defined as 'when looking into the socket'.

Headset socket
  1. MIC
    Mircophone (in)
  2. PTT
  3. SPK
  4. GND
  5. GND
Data socket
  1. GND
  2. ?
  3. ?
  4. ?
  5. ?
  6. GND
  7. ?
Switch pack connector
The pinout of the internal switch pack connector at the right side of the radio is based on information found on the internet, mainly from Brooke Clarke [3], and is subject to change. If you have additional information, please contact us.

  1. MIC
  2. ?
  3. SPK
    Speaker (out)
  4. V
    3V (out)
  5. GND
  6. PTT
  7. ?
    busy pips
  8. ?
  9. ?
  10. RX
    Data in
  11. TX
    Data out
  12. ?
Headset wiring
Base on the pinout of the 5-pin LEMO socket given above, a suitable headset or microphone/speaker combination with Push-To-Talk (PTT), should be wired as shown in the diagram on the right. The pinout of the LEMO socket is given when looking into the socket on top of the radio.   

    Enhanced Encrypted Personal Role Radio
  • GPS
    Global Positioning System
  • LPD
    Low Probability of Detection
  • LPI
    Low Probability of Intercept
  • PC
    Personal Computer
  • PRR
    Personal Role Radio
  • PTT
    Push To Talk
  • SF
    Special Forces
  • USB
    Universal Serial Bus
  1. AESP-5820-B-150-201, EZPRR - Operating Information

  2. AESP-5820-L-265-201, Casualty Locating Beacon (CLB)

  3. AESP-5820-C-108-201, CLB Information Management System (IMS)
  1. Selex ES Ltd, EZPRR Datasheet
    2013. Retrieved May 2015.

  2. Selex ES Ltd, EZPRR Datasheet
    2014. Retrieved June 2015.

  3. Brooke Clarke, Bowman H4855 AN/PRC-43 Personal Role Radio
    Retrieved May 2015.
Further information
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Crypto Museum. Created: Tuesday 26 May 2015. Last changed: Wednesday, 05 October 2016 - 04:43 CET.
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