Clansman Clansman is the name of a combat net radio system ( CNR ) used by the British Army from 1976 to 2010 . Clansman was developed by the Signals Research and Development Establishment ( SRDE ) in the 1960s , to satisfy a General Staff Requirement ( GSR ) laid down in 1965 . Most Clansman radio equipment was built by Racal , Mullard Equipment Ltd ( MEL ) and Plessey , although headsets and ancillaries were also produced by Amplivox , Marconi and others . Clansman represented a considerable advance over existing radios being offered to the Armed Forces at the time . It replaced the aging Larkspur radio system , and proved to be more flexible , reliable and far lighter . The technological advances achieved in the design of Clansman allowed the introduction of Single SideBand ( SSB ) operation and NarrowBand Frequency Modulation ( NBFM ) to forward area combat net radio for the first time . Clansman was in use by British forces from the late 1970s and saw service in most recent UK military operations . It was replaced in the mid - 2000s by the new Bowman communication system . Family . The Clansman family of Military Radio Sets comprises nine main radio units , operating in the High Frequency ( HF ) , Very High Frequency ( VHF ) and the Ultra High Frequency ( UHF ) Radio Bands . Models are designated " UK / PRC " or " UK / VRC " , which stand for " United Kingdom / Portable Radio Communicator " and " United Kingdom / Vehicle Radio Communicator " respectively . The radios first came into service in the late 1970s at that time the main advantage of the Clansman radios was that they were all frequency synthesised ( switched channels , as opposed to using a variable tuning scale for example ) . This provided frequency stability , obviating the need to tune the radio again , once a frequency was set . Previous UK military radios were much less stable , and had to be frequently tuned ( or might need to be tweaked to " pull in " a weak signal ) . Clansman HF Radio Sets . UK / PRC 316 . A late introduction to the Larkspur range , its original designation was A16 Lightweight HF Radio Station . Deployed in tropical or high temperature climates , it was powered by either a standard 12VDC Battery that connected directly to the set or if issued , a Leclanche Battery that connected directly to the set . It was compatible with most D10 or R4 Copper stranded antenna systems that was currently fielded at that time , some examples being the Shirley , Jamaica , Half Jamaica and Yagi . Despite not being of the Clansman family , its late introduction to service coupled with its Clansman equivalent , the PRC / RT320 not being ready meant the PRC 316 survived for just over 5 years once Clansman was introduced . Once the PRC / RT320 was completed and fully fielded , the PRC 316 was rapidly withdrawn . Another reason cited for its retention was that it was relatively easy to operate and was inter - operable with the other HF Radios in the Clansman family . UK / PRC 319 . Special Forces and STA Patrol man - portable , patrol level radio HF / VHF , Half - duplex transceiver capable of burst transmission which was built in the United Kingdom by MEL . Features include key - pad entry of frequency , mode and data with digital LCD display ; 10 pairs of pre - programmable channels ; half - duplex operation with the option of transmitting and receiving on different channels ; the option of using a removable pocket sized electronic message unit ( EMU ) to transmit and receive short data communications ; fully automatic antenna tuner which can be remoted up to 50m from the set using standard co - ax cable ; Self test facility . power output is 50 watts PEP on high power setting with an adjustable low power of 2 - 5 watts . Frequency range is 1 . 5 - 40 MHz allowing short range VHF communications overlap with the other clansman series radios on the higher frequencies . UK / PRC 320 . An HF / USB / AM / CW transceiver built by Plessey and issued down to company level . The set operates in the 2 - 29 . 9999 MHz range with a possible 280 , 000 channels . RF power output is a selectable 3 or 30 watts . derived from an earlier prototype known as the B20 . The PRC 320 can be used as a manpack ( backpack ) or vehicular radio and it originally replaced the Larkspur Station Radio ( SR ) A13 SR C13 and other HF Radios in service with the British Army . The PRC320 can be used with a number of different Clansman antennas that are supplied with the set ; A 2 . 4m whip antenna is supplied for portable manpack operation using HF groundwave communication . Alternatively a dipole antenna can be used for HF Skywave operation . See VRC 321 below for typical ranges achievable using these modes of propagation . The set includes a built - in Antenna Tuning Unit ( ATU ) , this electrically matches the whip antenna length to the radio frequency in use . The ATU can also match any other wire antenna to the operating frequency . The set together with its ancillaries ( batteries , cables , audio gear and antenna parts ) together make up the complete equipment schedule ( CES ) . It is a well known fact in signalling ( military radio operating ) that the use of morse code and later data transmission and reception could extend the range and add to the versatility of the UK / PRC 320 . After Market a number of data entry devices were produced as add ons such as MEROD , TDED and Kipling . Current Users . Clansman HF Sets are still in use in the UK by the Cadet Forces . Many of the sets have found their way into amateur service since the Clansman system became obsolete . UK / VRC 321 . An vehicle - borne High Frequency ( HF ) transmitter / receiver used for inter company communications outside of the normal working range of the VHF forward area nets it can also be used dismounted from a vehicle as a ground station with an external power supply or batteries and antenna system . It was also used for rear link communications up to Brigade level and administrative radio nets . The set uses USB / AM or CW with an RF output of 20 - 30 Watts . It was Manufactured by MEL at Crawley in Sussex and replaced the Larkspur SR C13 and C11 R210 HF Vehicle Stations . The radio is issued together with ancillaries to make up the operating station , inducing a power cable , antenna tuner unit , coaxial cables and antenna wires . Other accessories such as the selectivity unit radio frequency ( SURF ) were available . The SURF , when tuned , allowed more than one set to be operated from the same position without interfering with each other . The standard antenna tuning unit used with the UK / RT 321 is the Tuning Unit Radio Frequency ( TURF ) 25 Watts . This could be used either attached to the set , or remotely depending on which antenna configuration was used . UK / VRC 322 . A VRC321 station with the addition of a 300 Watt peak envelope power ( PEP ) linear amplifier ( ARF 250W ) and appropriate high power antenna tuning unit ( TURF 250 ) manufactured by MEL of Crawley , Sussex . Clansman VHF Radio Sets . UK / PRC 349 . An intra - section level portable VHF FM transceiver . Built by Racal BCC . RF power output is 0 . 25 watts . Units supplied to the British Army operate in the 37 - 46 . 975 MHz range , voice ( FM ) transmission Mode and 25 kHz channel separation . A high power ( 2 Watts ) output version was also available and any 10 MHz block in the range 30 - 76 MHz could be supplied . Worn in a holster on the chest or back . The PRC349 was added to the Clansman family in 1972 . UK / PRC 351 / 352 . An intra - platoon level backpack VHF FM transceiver . Built by Racal BCC . The PRC 351 has 4 watt RF power output , and operates in 30 - 75 . 975 MHz range with possible 1840 channels spaced 25 kHz apart . This radio is also capable of being mounted on a vehicle in conjunction with the TUAAM . The PRC 352 is identical , with the addition of a 20 watt RF amplifier and can be used as a ground station . UK / VRC 353 . A vehicle - mounted VHF FM transceiver built by Marconi Space and Defence Systems . The frequency range and channel separation is the same as the 351 / 352 with power settings up to 50 W . Antenna systems are provided to provide improved performance in semi - static situations such as an elevated broadband vertical dipole mounted on an 8 metre mast . The VRC is also capable of data transmission and when used in conjunction with an add - on unit ( Digital Master Unit ) provides a medium level secure speech network . Clansman UHF Radio Sets . UK / PRC 344 . A forward air control UHF AM transceiver . Built by Plessey . Operates in 225 - 399 . 9 range with 50 kHz steps for possible 3500 channels . RF power output is rated at 2 . 5 watts . Batteries and Charging . Manpack and Portable Stations . Re - chargeable batteries were supplied for all of the portable range of radios . The PRC 344 , PRC 351 , 351 / 2 and PRC 320 all shared the same common battery - the 24 Volt 3 . 3 Ampere \ Hour Nickel Cadmium ( NICAD ) type later upgraded to 4 Ampere \ Hour ( or Ah ) . Each radio would be issued with three batteries , and a range of battery charger s was available for this common battery . With the exception of the PRC 349 which was 12 Volt ( nominal ) , The Manpack and Portable sets and their chargers were almost all nominally rated 24V DC ( Direct Current ) to match the British Army ' s choice of 24 Volts to power its vehicle systems . The Direct Current Charging Units ( DCCU ) was used to float charge ( provide a top up charge while the set was in use ) the manpack battery , while it was mounted in a vehicle , using a clip in kit for example . It could also provide a full charge cycle over 4 . 5 Hours from flat , switching itself out of circuit when complete . ( A clip - in kit locked the radio in a convenient frame for rapid deployment when dismounting , and had the charger as part of the installation . ) There were a few exceptions where 24 Volts was not used in vehicles , such as in the General Service ( GS ) Landrover where a 12v system was used for example . A 12 Volt DCCU was provided . The Clansman 24V 4Ah Nickel Cadmium Battery was prolific and for convenience an Alternating Current Charging Unit ( ACCU ) was provided for use in barracks where up to sixteen batteries could be charged simultaneously or singularly . All of these chargers worked the same , basically providing an appropriate charging current while sensing the battery temperature to detect when charging was complete , achieved by measuring the voltage across two sets of a series pair of silicon diodes in the battery itself , one series pair would sence the internal temperature of the cells the other series pair fitted close to the outer case of the battery to sence ambient temperature , the difference in temperature being used to determine the state of charge . One drawback of the Clansman 24V 4Ah NICAD is that failure of these diodes makes batteries unserviceable . Also due to partial charge cycle s due to the ' memory effect ' of the Nicad cells . A discharge process could have prevented such failures , but was not provided for in either the DC or ACCU . Specialists can rebuild the unserviceable Clansman NICAD battery . Later an intelligent battery management system ( IBMS ) was provided which automatically conditioned one or more batteries , a process which ensured only complete charge cycles were applied , in order to avoid the NICAD memory effect . The PRC 349 was originally intended for use with 1 . 5V AAA Alkaline batteries and provided with a cassette to hold them . As these became more expensive a variety of mains adapters and nickel cadmium batteries came into service . A lithium version was later introduced as a lightweight replacement for the 24V 4Ah NICAD . Vehicle Sets . These were nominally 24 Volt and were powered by lead acid batteries which were charged by the vehicle alternator , an auxiliary engine fitted to the vehicle , or a charging engine or generator - particularly when ground mounted or static . AC Adapters , Transformers and Switched Mode Power Supplies . A number of AC Mains units were provided so that sets could be used in barracks . Clansman Control Harness and Accessories . Clansman Control Harness refers to a range of accessories which were fitted into vehicles for the purpose of controlling the set ( s ) and providing other features such as loud speakers , a vehicle intercom system , and switching between two radio sets . Control boxes provided the switching and facilities to plug the audio gear into . Clansman Audio Gear . A Range of Audio Gear for use in various roles are commonly provided such as ; the Lightweight ' B ' Vehicle and Infantry Headset ( Headset BV and I ) , the Clansman Handset , a Pressel ( Press to Talk or PTT ) Switch and the Audio Gear Staff User ( AGS ) . The AGS featured Special Sonovalve technology - a feature designed to allow background noise into the headset through a special valve . In Armoured fighting vehicles an Electronic Automatic Noise Reducing System was provided . Clansman Accessories . IBRU ( Interconnecting Box Radio - rebroadcast Unit ) . Used in conjunction with the " Harness " point on VRC 353 and VRC 321 units , to operate 2 or more sets as a Rebro . ( ReBroadcast ) . Re - Broadcasting allows 2 + networks , on different frequencies , to be combined , effectively increasing the ground size of the net . For instance , a vehicle using whip antennas may only be able to communicate 30 km ; though placing a Rebro vehicle 30 km away could extend this to 60 km by re - broadcasting the signal on a second net . DMU . A Digital Master Unit or DMU is used to provide digital communications and to provide secure encrypted communications on a VHF network , when working to similarly equipped radios . This required additional equipment such as the BID 250 and associated Crypto key material . SURF . A SURF ( Selector Unit Radio Frequency ) is used to prevent interference to operation of the radio sets . The SURF is an electrical filter , designed to reject unwanted interference from other radios when operating in close proximity to each other . The SURF is tuned using a manual control on the front of the unit , so that only the frequency in use , and those close to it , are accepted by the set . A Range of SURFs were provided for attachment to the VHF PRC350 , PRC351 / 2 ( SURF 4 Watt ) and also the HF PRC320 ( SURF 12 Watt ) and VRC 321 ( SURF 25 Watt ) . Antenna Tuning and Matching . TURF . A TURF ( Tuning Unit Radio Frequency ) is an Antenna Tuning Unit or ATU . It is used to artificially lengthen the antenna ( or tune it ) Often at HF wavelengths for example an antenna would be physically too long to attach to a radio without affecting portability and manoeuvrability . A shorter vehicle whip was more practicable and also field antennas were constructed with for example , vertical radiators constructed using the Racal 8 or 12 metre masts . Because these were an electrical compromise , they had to be tuned by use of a TURF ( or electrically matched to the set ) . The TURF 25 Watt ( a separate unit to the radio ) is considered mandatory when using the VRC321 it tunes both unbalanced , end fed wires and whips and also balanced antenna such as the dipole . An antenna tuning unit is built into the manpack PRC 320 . The TURF requires users to manually tune the antenna , unlike the VHF " TUAAM " which is an Automatic Tuning Unit . TUAAM . A TUAAM ( Tuning Unit Automatic Antenna Matching ) is an ATU which matches the antenna at VHF and which is used mainly with the VRC 353 and PRC 351 / 2 ( when used with the clip - in kit and mounted in a vehicle ) . The TUAAM automatically tunes the antenna , and artificially shortens it rather than lengthening it , but essentially it performs the same function as a TURF . Clansman Antenna . A Range of Antennas specially manufactured for use with Clansman Radio : Elevated VHF Antenna ( EVHF ) . An elevated end fed dipole for use with the VHF Radio to extend the range when mounted on an 8 or 12 Meter Mast .