MOULD Home Defence Radio

This topic is a simplified description of the defunct MOULD radio system. The original phase provided one system per home defence sub-region and employed 120 hilltop sites. A later contract extended this with the addition of County networks bringing the number of separate networks to ninety and increased the hilltop sites to 150. Based on an article in 'The Wire' circa 1986, by A F Carter with the addition of my own observations.


MOULD first came to my notice in January 1987 when an article in the RSGB Radcom warned radio amateurs that links between MOULD hilltops were using the 70 cm band that we shared on a secondary basis with the Ministry of Defence (MOD). The article explained that MOULD would provide communications between Regular Army, TA Battalions and the Army District and Regional Headquarters. Phase 1 cost £7m to install and used 18-channel Pye Pegasus radios operating at 66-88MHz. A network of hilltop sites were linked together to give area coverage. These bearer links used 140-150MHz and 420-450MHz in a formation giving a maximum of 7 radio hops between users.
Having been alerted to the presence of the system, I was able to find the frequencies being used locally for the area coverage and the inter site links. I never had the inclination to investigate military communications and back then did not appreciate MOULD's connection with home defence. Only after the scheme closed down has this become apparent, in June 2009 I obtained a copy of a technical article published in the mid-eighties that has filled in the gaps in my knowledge and is the basis for this page. Further information was forthcoming in 2010 and 2011 allowing more specific details to be added.
MOULD closed during the two thousands and the users have been transferred to AirWave the common system for UK Emergency Services' communications used by the Police, Fire and Ambulance authorities. The MOULD equipment was being recovered from hilltop sites during 2008.

The Radio Network

Phase 1 of the UK Army MOULD radio system was introduced in 1976 - 77 in England, Scotland and Wales, but not Northern Ireland, as a communications system was already in place there. It was designed to give area coverage in each home defence region, these align with the civilian Regional Government Headquarters boundaries. In the mid-eighties, Phase 2 provided additional schemes giving area coverage in each county.
Phase 1 MOULD Network, Region 7
Region 7
In order to give area coverage a number of hilltop sites with rebroadcasters working in the VHF low band, were connected together with radio links, operating in VHF high band or UHF. In this drawing of the network in Home Defence Region 7, there are two sub networks. In the Sub-Region 7.1 under control of the RGHQ at Chilmark, there are nine hilltop sites, and nine in Sub-Region 7.2 controlled by Bolt Head RGHQ. Three sites Middleton Court, Cranmore Tower and Newton Barrow are common to both networks and have rebroadcasters on both networks. The schemes were carefully designed so there are no more than five links in between any two sites. In Sub Net 7.2 for example, the extremities at Four Lanes or Collaton Cross, are only five links away from Newton Barrow.
Countrywide, Phase 1 employed 120 hilltop sites. This increased to 150 when Phase 2 was implemented. Most of the English and Welsh hilltop sites chosen for MOULD were those in use by the emergency services and UKWMO / GCN. Some MOD, Civil Aviation and Broadcasting sites were used too. All the hilltop radio equipment was maintained by the No.2 Signals Brigade.
In Phase 1, the MOULD mobile and fixed sets were 18 Channel crystal controlled Pye M252 Pegasus transceivers, outputting 5 to 15 Watts in the 79MHz band and receiving in the 74MHz band. In Phase 2, Pye FM914, 25 Watt synthesized 250 channel transceivers were used.
The hilltop radio equipment was all mains operated. The rebroadcaster equipment was Pye 400 Series, 60 Watt transmitter with a separate receiver, operating in the VHF low band. VHF high band links, using a Pye T404, 25 Watt transmitter and separate R404 receiver. UHF links using a Pye T414, 5 Watt transmitter and separate R414 receiver.
The hilltop rebroadcasters and mobiles, use frequencies in military bands, shared with other fixed and mobile military services. I don't know the exact upper and lower limits of the bands used for the VHF and UHF links, but the approximate band edges are given below.
For example, in my notes recorded during an exercise in October 1988, 74.050MHz, 74.125MHz, 74.200MHz, 74.525MHz, hilltop transmit frequencies were all carrying the same traffic. I now find out in 2011 these were four of the five transmitters on the Region 9 Principal Net., which covers the area where I live.

Network Design

The design of the MOULD network is very different from the wide area schemes used by the emergency services. Emergency services have a number of hilltop locations all transmitting and receiving on the same frequency and linked back to a single control point. A full description is given in the 'Emergency Services Radio / Pre 1987' in the website menu. In contrast each of the MOULD hilltop sites use different pairs of transmit (TX) and receive (RX) frequencies to give area coverage. The MOULD network did not have a central control point so adjacent sites were linked together in an open network. A limit of five serial links was imposed to ensure reliable communications.
On any particular network, each hilltop was permitted to have a maximum of five links to other sites. Cranmore Tower, one of the sites shown on the Region 7 map has five links in sub-network 7.1. There are also two links forming part of network 7.2, but this has a separate set of equipment. In Phase 2, and therefore not shown in the drawing above, Cranmore Tower got a third set of equipment working on the Somerset County network.
Mobiles accessing MOULD Network
Hilltop sites
Referring to the diagram above this text, each mobile would select the channel used at the nearest hilltop. For mobiles M1 and M2 this would be Channel 5. If M1 called M2, its signal would be received at the hilltop and be rebroadcast so M2 could hear it. As well as simply rebroadcasting the signal, it would be sent on the link to the next hilltop and broadcast on Channel 4, this site would relay the signal on the link to the next site. Here it would be broadcast on Channel 2, so mobile M4 could hear the signal. This site is linked to two others, where it would be broadcast on Channels 1 and 3. Mobile M3 would also hear the signal on Channel 1. If mobile M3 called mobile M2, it would transmit on Channel 1, its message would be similarly broadcast by all sites on the network, so all four mobiles including M2 would hear the message.
Hilltop Site Control Unit Logic
Control Logic
The hilltop radio equipment was controlled by a 'Control Switching and Signalling Unit' (CSSU). The CSSU routed the signal from the receivers to the appropriate transmitter. The logic diagram shows that any signal received on the low band area channel was rebroadcast by the area channel transmitter and all the link transmitters. A signal received on a particular link would be broadcast by the area channel transmitter and sent out on all the other links except the originating link.
Where two or more networks shared the same hilltop, the CSSU may be configured to link together two networks for operational reasons, usually a 'Principle' Regional Net. and a County Net.
Whereas the emergency services radio schemes had all their transmitters and receivers duplicated, this was not the norm for MOULD, except at the more remote hilltop sites where access could be difficult in adverse weather conditions. To guard against the loss of a hilltop site, due to wartime action or a fault, mobile units known as 'Insertion Vehicles' were kept on standby, so they could be driven to the site to replace it, while repairs were undertaken.
Insertion Vehicle and Support
Insertion Vehicle exterior
The 'Insertion Vehicle' is a hardtop Landrover, with a supporting stores vehicle, and a generator. It contains the same equipment used in the hilltop installation. The radios are channeled to allow them to replace any of the MOULD hilltops within the Region it supports.
Radio Installation inside the Insertion Vehicle
radio installation
Both Vehicle Photographs Courtesy of Martin Swift
MIV Addition Rebroadcaster Allocation
These channels are arranged so the insertion vehicle can act as an additional hilltop site for the mobiles within the region. These channels form part of the Pegasus 18 channels, the remaining channels allow it to replace a non functioning hilltop rebroadcaster.
The insertion vehicle's radio is programmed so its transmitter uses the opposite band to a normal mobile, in this case the lower band (74-75 MHz), whereas normally a mobile would transmit in the upper band. The receive is the opposite way too, listening in the higher band, a normal mobile listens in the lower band.
The final column in the list below shows the Pye 914 radio channel, that normal mobiles would select to use the special rebroadcaster on the insertion vehicle. Listening on the MIV TX and transmitting on the MIV RX frequency.
914 Set
Ch. No.
3 & 74.087578.9875117
3 & 74.300079.9125242
MIV Pegasus Allocations in Region 2
These channels are arranged so the insertion vehicle can replace a non functioning hilltop that may have been destroyed by enemy action.
The list identifies the hilltop and the Regional or County Net at that hilltop, that it replaces. The last two channels are additional Regional Channels that are not present at any hilltop. A full list of hilltop channels for Region 2 may be found in the section further down this page Regional Maps and Frequency Data
Region 2; Insertion Vehicle PATTERN ONE Radio
914 Set
Ch. No.
Net / Hilltop Site
1Humberside / Weedley74.625079.8625
2Principle N / Trimdon74.562579.7375
3S Yorks / Clifton74.687579.8375
4Training / Garrowby Hill74.375079.0875
5W Yorks / Golcar74.637579.5375
6Principle N / High Spen74.45079.9125
7Principle S / Richmond Outmoor74.200079.5875
8Durham / Colliers Law74.312579.6375
9Principle N / Richmond Outmoor74.312579.3375
10Northumberland / Ottercops Moss74.650079.1625
11Principal S / Garrowby Hill74.187579.2375
12Cleveland / Trimdon74.600079.7875
13N Yorks / Greenhow Hill74.612579.0675
14N Yorks / Ravenscar74.587579.6625
15N Yorks / Garrowby Hill74.137579.9625
16MIV Rebroadcaster 174.037579.4375
17MIV Rebroadcaster 274.400079.8125
Region 2; Insertion Vehicle PATTERN TWO Radio
914 Set
Ch. No.
Net / Hilltop Site
1Principal S / Clifton74.075079.0375
2Principal S / Golcar74.575079.6375
3Principal S / Ravenscar74.012579.0125
4Principal S / Richmond Outmoor74.200079.5875
5Principal S / Weedley74.412579.4625
6Principal S / Garrowby Hill74.187579.2375
7Humberside / Weedley74.500079.7625
8Principal N / Trimdon74.562579.7375
9Principal N / Colliers Law74.050079.1875
10Northumberland / Brizlee Wood74.100079.2125
11Northumberland / High Spen74.275079.3875
12Cleveland / Trimdon74.600079.7875
13N Yorks / Garrowby Hill74.137579.9625
14N Yorks / Richmond Outmoor74.662579.6875
15Durham / Trimdon74.025078.9875
16MIV Rebroadcaster 174.037579.4375
17MIV Rebroadcaster 274.400079.8125

The Full Details - An Example from Region 8

MOULD Region 8 Radio Scheme with Radio Frequencies
In Wales there were two Principal Networks, Region 81 in the North and Region 82 in the South, corresponding with Brackla RGHQ 82 and a nonexistent RGHQ 81. There were eight County Networks in Wales, in Region 81, Clwyd and Gwynedd; in Region 82, Dyfed, Mid, South and West Glamorgan, Gwent and Powys.
The County Networks consisted of one or more hilltop sites, Mid Glamorgan had one rebroadcaster whereas Powys had a network of four. If desired, county networks could be coupled in with the regional Principal Network. Abergavenny was the coupling point for both Gwent and Powys, into Principal for Region 82. Dyfed could be coupled at Mynydd Sylen into Region 82 Principal net. Network control including coupling was performed remotely by the use of SELCALL signals. The hill top site at Old Pale is located in Region 10, but also serves Region 81, with rebroadcasters on networks for Region 10 Principal, Cheshire and Merseyside; Region 81 Principle and Clywd. Similarly Brown Clee is located in the West Midlands Region 9, but also serves Region 81 Principle Net.

18 Channel Mobiles

Channels in a Region 2, Pye M252 Mobile

Pye Pegasus M252
Pye Pegasus
The Pye Pegasus M252 wireless sets used in Phase 1 of MOULD were able to select one of eighteen channels, restricting their use to one defence region. Some regions required two patterns of channel variants. In Region 2, Set No.1 could operate through all nine sites in the 'Principal Net', four on the north and five on the south. A choice of two sites for 'North Yorkshire County Net' but only a single site for the remaining 'County Nets'. Channel 17 is allocated to the Mould Insertion Vehicle (MIV) should it need to be deployed. The Region 2, No.2 type set had a different variation of radio channels, with the emphasis on 'County Nets' as can be seen from the tables below. Some defence regions were divided into two sub-regions aligned with the civilian sub-regional government areas of the RGHQ, an example being Region 8, Wales, divided into subregions 81 & 82.
Click Tabs to see Regional Pegasus Set Allocations
Allocation Chart
The limitation of only 18 channels meant army home defence forces could not be deployed outside their own region. This shortcoming was addressed in Phase 2 by the introduction of sets with 250 channels.

250 Channel Mobiles

The Pye 914 set having 250 channels, was able to cover every network in the whole of England, Scotland and Wales. Northern Ireland was not part of the MOULD scheme. The channel allocations and link maps are shown further down in this chapter, but a complete list is available for downloading.
Pye 914 and Selcall Unit
Pye Radio 914

National List of Sites including TX & RX Frequencies

All these PDF documents are under 40 Kb in size and require the case sensitive password RingBell to open them.
Most of the frequencies were used more than once across the whole country. The separation between sites using the same frequency being sufficient to avoid interference. This series of PDF document lists the Hilltop Transmit Frequency, Receiver Frequency, Channel number for the Pye 914 Radio, Site Name and Network Name in various sorted sequences.
To prevent undesirable indexing of these PDF documents by Web Crawlers, they are encoded, requiring a password to open. I am sorry if this is a nuisance, but html allows whole pages to be excluded from search engine indexes, but not the documents linked from a page.

Regional Maps and Frequency Data

A 'Net' or network consists of one or more hilltop sites all broadcasting the same messages. The map shows the radio links between hilltop sites used to create these networks. Links between hilltop sites were either single channel at VHF or UHF frequencies or two channels per link frequency using a 1 + 1 carrier system with a 'Pye RTU' at each end of the link. VHF links being used across longer hops or difficult terrain where UHF couldn't provide a reliable path. These links are shown on each Regional map according to the Key here. In some places, two separate radio links operating on different frequencies connected hilltops together, these appear as two parallel lines on the map.
A detailed explanation of 1 + 1 speech multiplexing used by MOULD links is provided in a separate chapter on this website. Found in the Miscellaneous Topics part of the Chapter Menu.
Key for Regional Maps
Key to Maps
The last two columns give the frequencies that were in use by MOULD rebroadcasters, TX frequency is transmitted from the hilltop and RX is transmitted by the mobile (or fixed mobile stations).
Networks in Region 1 Scotland
CCP Block Schematic
Small map
Collafirth Hill51 North74.337579.5375
Latheron51 North74.012579.4625
Mossy Hill51 North74.012579.0625
Mount Eagle51 North74.675079.6875
Saxa Vord51 North74.150079.1875
Wideford51 North74.050079.0375
Bat a Carchel51 South74.512579.6625
Brimmond Hill51 South74.637579.7375
Cairn Mon Earn51 South76.012584.6375
Cairnpapple51 South75.787584.4625
Craigowl51 South76.325084.8375
East Lomond51 South74.700079.6375
Mount Eagle51 South74.300079.1125
Pitlochry51 South74.025079.0875
Tom A Chait51 South74.187579.2375
Torslaisg51 South74.587579.8875
Garve51 West74.250079.2875
Melvaig51 West74.100079.2125
Mount Eagle51 West74.725079.7875
Tom A Chait51 West74.537579.0375
Brown Carrick52 Net74.437579.2000
Cambret Hill52 Net74.462579.7750
ClachMacKenny52 Net74.037579.1375
Clermiston52 Net74.400079.5375
Dunnion Hill52 Net74.687579.7125
Dunslair Heights52 Net74.025079.0875
Green Lowther52 Net74.112579.8000
Kirk O Shotts52 Net74.712579.7875
Sergeants Law52 Net74.200079.3125
South Knapdale52 Net74.287579.0875
Bat a CarchelCentral74.312579.2625
Caldons HillDumfriesGalloway74.187579.3875
Cambret HillDumfriesGalloway74.312579.7250
Green LowtherDumfriesGalloway74.362579.8875
East LomondFife74.612579.5875
Brimmond HillGrampian74.525079.6125
Cairn Mon EarnGrampian75.912584.2125
Mormond HillGrampian74.262579.2625
Dunnion HillLothianBorders74.150079.5875
Dunslair HeightsLothianBorders74.537579.0375
Brown CarrickNorth Strathclyde74.212579.6250
CampbeltownNorth Strathclyde74.300079.1125
ClachMacKennyNorth Strathclyde74.550078.9875
CruachenNorth Strathclyde74.612579.7875
Sergeants LawNorth Strathclyde74.275079.8625
SloyNorth Strathclyde74.350079.4625
South KnapdaleNorth Strathclyde74.150079.5875
Brimmond HillPrincipal Region 174.737579.3125
Cairn Mon EarnPrincipal Region 175.737584.0875
ClermistonPrincipal Region 174.237579.3375
CraigowlPrincipal Region 175.937584.4375
Dunslair HeightsPrincipal Region 174.187579.2375
Green LowtherPrincipal Region 174.612579.8375
Kirk O ShottsPrincipal Region 174.587579.6875
Mount EaglePrincipal Region 174.562579.5625
PitlochryPrincipal Region 174.087579.1875
Sergeants LawPrincipal Region 174.087579.0250
TorslaisgPrincipal Region 174.650079.7125
ClachMacKennyRoyal Marines74.225079.5625
Collafirth HillShetland74.037579.8875
Mossy HillShetland74.462579.3875
Saxa VordShetland74.237579.6125
Brown CarrickSouth Strathclyde74.487579.6000
ClachMacKennySouth Strathclyde74.675079.8375
Green LowtherSouth Strathclyde74.062579.9125
Kirk O ShottsSouth Strathclyde74.262579.2125
Sergeants LawSouth Strathclyde74.162579.4375
SuidheSouth Strathclyde74.337579.5125
ClettravalWestern Isles74.162579.4375
EitshalWestern Isles74.737579.3125
Networks in Region 2 North East
MOULD Region 2
Area Map
Colliers LawDurham74.362579.5375
WeedleyNorth Humberside74.625079.8625
Garrowby HillNorth Yorks74.137579.9625
Greenhow HillNorth Yorks74.612579.0625
RavenscarNorth Yorks74.587579.6625
Richmond OutmoorNorth Yorks74.662579.6875
Brizlee WoodNorthumberland74.100079.2125
High SpenNorthumberland74.275079.3875
Ottercops MossNorthumberland74.650079.1625
CliftonPrincipal Region 274.075079.0375
Colliers LawPrincipal Region 274.050079.1875
Garrowby HillPrincipal Region 274.187579.2375
GolcarPrincipal Region 274.575079.6375
High SpenPrincipal Region 274.450079.9125
RavenscarPrincipal Region 274.012579.0125
Richmond OutmoorPrincipal Region 274.312579.3375
TrimdonPrincipal Region 274.562579.7375
WeedleyPrincipal Region 274.412579.4625
WeedleySouth Humberside74.500079.7625
CliftonSouth Yorks74.687579.8375
Garrowby HillTraining74.375079.0875
Richmond OutmoorTraining74.200079.5875
GolcarWest Yorks74.637579.5375
Networks in Region 3 & 4 East Midlands & Anglia
MOULD Region 3 + 4
Area Map
Alport HeightsDerbyshire74.262579.2625
AlconburyDistrict Command74.412579.4625
Alport HeightsDistrict Command74.537579.6875
Back StreetDistrict Command74.262579.2625
BarkwayDistrict Command74.112579.1125
Brink HillDistrict Command74.362579.5375
Glebe FarmDistrict Command74.025079.0125
Great BromleyDistrict Command74.425079.4625
SpitalgateDistrict Command74.162579.1625
StenigotDistrict Command74.212579.3125
Stoke Holy CrossDistrict Command74.050079.1875
StreatleyDistrict Command74.325079.4875
Danbury BeaconEssex74.600079.7875
Great BromleyEssex74.687579.6875
Copt OakLeicestershire74.550079.6125
Glebe FarmLeicestershire74.462579.4875
Brink HillNorfolk74.012579.0625
Stoke Holy CrossNorfolk74.650079.7875
Berry HillNottinghamshire74.437579.5125
Kirton in LindseyNottinghamshire74.475079.4875
BarkwayRegion 4 Principal B74.025079.0125
BedmondRegion 4 Principal B74.450079.7375
Danbury BeaconRegion 4 Principal B74.500079.6625
Great BromleyRegion 4 Principal B74.625079.6125
StreatleyRegion 4 Principal B74.512579.6375
Alport HeightsRegional74.650079.7875
Back StreetRegional74.137579.1375
Brink HillRegional74.737579.7625
Glebe FarmRegional74.225079.2125
Stoke Holy CrossRegional74.187579.3875
Peasenhall / LinsteadSuffolk74.225079.2125
Networks in Region 5 London
MOULD Region 5
Area Map
Hyde ParkLondon North75.825084.1500
Hyde ParkLondon North East76.062584.2625
HillingdonLondon North West76.325084.8375
Botley HillLondon South East75.737584.0875
Hyde ParkLondon South West76.225084.3625
Botley HillPrincipal Region 576.437584.7625
HillingdonPrincipal Region 575.875084.7125
Hyde ParkPrincipal Region 576.500084.8500
Networks in Region 6 South East
MOULD Region 6
Area Map
Christmas CommonBerkshire74.387579.4375
Christmas CommonBuckinghamshire74.150079.3125
Crabwood FarmHampshire74.650079.6125
Dean HillHampshire74.362579.2875
Golden PotHampshire74.262579.2125
St Boniface DownHampshire74.587579.6625
Coldblow LaneKent74.537579.5125
Christmas CommonOxfordshire74.075079.1625
Botley HillRegion 6 Principal A74.037579.1875
Burton DownRegion 6 Principal A74.050079.0375
Coldblow LaneRegion 6 Principal A74.462579.3875
CrowboroughRegion 6 Principal A74.550079.5625
Golden PotRegion 6 Principal A74.062579.2625
SwingateRegion 6 Principal A74.162579.1625
Christmas CommonRegion 6 Principal B74.012579.0625
Crabwood FarmRegion 6 Principal B74.487579.2375
Golden PotRegion 6 Principal B74.025079.0125
Botley HillSurrey74.337579.3375
Golden PotSurrey74.312579.5375
Burton DownSussex74.125079.1375
Networks in Region 7 South West
MOULD Region 7
Area Map
Bulbarrow Hill71 Net75.875084.5125
Cleeve Common71 Net75.787584.4625
Cranmore Tower71 Net76.437584.7625
Middleton Court71 Net76.225084.3500
Morgans Hill71 Net76.362584.2875
Newton Barrow71 Net75.937584.4375
Swymmers Farm71 Net75.912584.2125
Caradon Hill72 Net75.862584.3875
Collaton Cross72 Net76.325084.5750
Cranmore Tower72 Net76.325084.5750
Gittisham72 Net76.062584.8625
Hensbarrow Down72 Net75.962584.2375
Middleton Court72 Net75.750084.5875
Tichbarrow72 Net76.112584.0375
Swymmers FarmAvon76.537584.8500
Caradon HillCornwall75.912584.2125
Four LanesCornwall75.750084.5375
Hensbarrow DownCornwall75.825084.1500
Beacon HillDevon76.500084.8500
Caradon HillDevon76.362584.2625
Collaton CrossDevon76.012584.6375
Huntshaw CrossDevon76.475084.7875
Bulbarrow HillDorset76.075084.0875
Cleeve CommonGloucestershire76.475084.7875
Morgans HillGloucestershire75.862584.0125
Cranmore TowerSomerset76.112584.0375
Middleton CourtSomerset76.162584.1875
Dean HillWiltshire76.475084.7875
Morgans HillWiltshire75.962584.2375
Newton BarrowWiltshire76.012584.6375
Networks in Region 8 Wales
MOULD Region 8
Area Map
Old PaleClwyd74.062579.1125
Mynydd SylenDyfed74.200079.4375
Pembroke DockDyfed74.612579.7875
Gaer HillGwent74.325079.3375
Mynydd RhiwGwynedd74.400079.9125
Twyn HywelMid Glamorgan74.012579.8875
Pen Y FforestPowys74.600079.6375
Ysgwydd HwchPowys74.450079.4625
Brown CleePrincipal 8174.087578.9875
Craig-y-DdualtPrincipal 8174.337579.3625
GwaenysgorPrincipal 8174.025079.1625
LlandonnaPrincipal 8174.362579.4125
Mynydd RhiwPrincipal 8174.262579.2625
Old PalePrincipal 8174.725079.8125
Ysgwydd HwchPrincipal 8174.137579.8125
AbergavennyPrincipal 8274.112579.1125
Mynydd SylenPrincipal 8274.587579.6625
Pembroke DockPrincipal 8274.562579.5125
Twyn HywelPrincipal 8274.387579.4125
Ysgwydd HwchPrincipal 8274.312579.2625
St Hilary DownSouth Glamorgan74.675079.7125
Twyn HywelSouth Glamorgan74.700079.7625
Foel FynyddauWest Glamorgan74.262579.3125
Networks in Region 9 Midlands
MOULD Region 9
Area Map
Dinmoor HillHerefordWorcester74.225079.2125
Brown CleePrincipal Region 974.200079.4375
Dinmoor HillPrincipal Region 974.687579.7125
NebsworthPrincipal Region 974.050079.3875
Pye GreenPrincipal Region 974.125079.2875
RomsleyPrincipal Region 974.525079.3125
Brown CleeShropshire74.037579.1375
Pye GreenStaffordshire74.012579.0625
RomsleyWest Midlands74.500079.6625
Networks in Region 10 North West
MOULD Region 10
Area Map
Old PaleCheshire74.350079.1875
Great Dun FellCumbria74.137579.9625
Great HillCumbria74.250079.4125
Shap FellCumbria74.075079.0375
Winter HillGreater Manchester74.675079.7125
SnaefellIsle of Man74.387579.9125
Winter HillLancashire74.212579.8625
Old PaleMerseyside74.587579.8875
BarnacrePrincipal Region 1074.712579.7875
Great Dun FellPrincipal Region 1074.225079.2875
Great HillPrincipal Region 1074.012579.0625
Old PalePrincipal Region 1074.150079.4625
Shap FellPrincipal Region 1074.412579.4625
SnaefellPrincipal Region 1074.237579.5750
Winter HillPrincipal Region 1074.112579.8000

Simplex Operation

Regional channels were allocated for direct vehicle to vehicle operation when they were in range of each other. The set's transmitter and receiver both operate on the same frequency.
Simplex Frequency Allocations
914 Set
Ch. No.
Region 179.7625232
Region 279.2625233
Region 3 & 479.7125234
Region 679.7625232
Region 879.5875235
Region 979.5625236
Region 1079.6625237

Civilian Access to MOULD

The Pye CAT 80 Low Band 80 MHz aerial shown to the right, were used for MOULD as well as commercial Public Mobile Radio (PMR). They were made by Telecommunications Limited (TCL) of Dublin Ireland, which eventually became Sigma prior to its closure, following a buyout of the antenna business of Sigma by American PCTel. TCL / Sigma was a feeder factory for Pye Telecom.
CAT 80 MOULD Aerial
MOULD Aerial
Regional Government Headquarters (RGHQ) had access to MOULD. Local Authority Emergency Control (LAEC) centres had MOULD aerials fitted, either the CAT80 shown here on Dudley Borough LAEC or a folded dipole. The LAEC also had access to the council's own radio scheme, generally used countywide by their highways departments. Post cold war in Cambridgeshire, they tried and tested an interlink between the council's radio scheme and MOULD, allowing direct communication between the two systems. This was demonstrated at a civil protection conference at Scarborough in June 1995.
In the nineties a program of fitting MOULD aerials to civilian buildings was undertaken. Aerials were fitted to larger telephone exchanges and wired down to the protected accommodation in their basement, but no radio equipment was connected. As CAT 80 aerials have been spotted on other public buildings as well as Police and Fire stations, these may have been wired for MOULD too. I can only speculate that this would allow military liaison at those places in a civil emergency.
During the eighties a number of local authorities, predominantly Labour Party controlled, declared themselves as 'Nuclear Free Zones'. The Army had some of their MOULD vehicles painted in brighter colours and bore civilian number plates for use in those sensitive local authority areas.
MOULD Vehicles in Civilian Colours
Civilian Colours
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