9 August 2013, 17:11
This started out as a quick estimation of how many stations would have to be operational to achieve full UK coverage. It grew a little out of control, but may help someone making choices.
The calculation is an under estimate as it does not take account of ground topology, nor the elongated shape of the UK
Ranges used are fairly typical for each class of radio.
Land area of UK is 243,610 Sq Km
PMR 446 Ave range =1.5km Number of stations to cover UK: 34,500
Ham HT UV5r type Ave range = 6.0km Number of stations to cover UK: 2,200
As base stn Avg range =20 km Number of stations to cover UK: 200
CB ( Fm) Ave Range = 8 km Number of stations to cover UK: 1300
As base stn Avg range =20 km Number of stations to cover UK: 200
CB ( SSB) Ave Range = 15km Number of stations to cover UK: 350
As base stn Avg range =30 km Number of stations to cover UK: 90
Ham NVIS Ave Range =100km Number of stations to cover UK: 12
Evaluation:
PMR446
More than 34,000 stations needed for national coverage!
Simple to operate. No antenna set-up issues, but CTCSS features complicate things somewhat.
Only useful for tactical and portable LOCAL communications. Not suitable for inter-survivor communications between dispersed fixed groups.
Huge number in circulation in the community: These will be scavengable items post event as many will be discarded once their power packs are depleted.
UV5r type Handhelds
Complex to set up and operate.
16x the coverage of PMR446. Suitable for tactical and portable local communications. Capable of inter village comms between fixed stations.
As a base station vertical antennas designed for vehicle use are small and relatively unobtrusive
Inter operable with PMR446, the 67,000 ham operators currently registered in the UK
Inter operable with maritime stations, coast guard and rescue services.
CB FM
The most simple radios to operate, although setting up antennas needs some skill and knowledge ( hand held units with built in antennas overcome even this)
28x the coverage of PMR446. Suitable for tactical local communications. Capable of inter village comms between fixed stations. Mainly designed for motor vehicle installation but these units are relatively small and can be made portable by constructing Man packs. Some hand held versions available ( Intek for ex)
As a base station vertical antennas designed for vehicle use can be small and relatively unobtrusive For best range we have to install 5m long horizontal wire antenna or 2.5m tall vertical.
Inter operable with an unknown number of existing CB stations in UK. As a base station, occasionally conditions will support communications out to 1000km range, but this is nor a reliable feature.
CB SSB
This is the 12watt EU standard that is soon to be legalised for license free use in the UK.
More complex to operate than normal CB, but too mush so, with identical antenna set up requirements
100x the coverage of PMR446, and 6 to 30 times the coverage of FM CB. Suitable for tactical and near region community communications between portable, mobile and fixed stations. Mainly designed for motor vehicle installation, these units are larger than hand helds, but can be made portable by constructing Man packs. Some self-contained hand held versions are available for portable use ( Albrecht for ex)
Versions of this type of radio are available that feature variable power, which is very useful as it allows us to use just enough power to make the contact, whispering, so to speak as opposed to shouting and drawing too much attention to us. Extended frequency range radios are also available that cover not just UK licensed CB frequencies but those of USA as well. In addition many of this class of radio will operate on two Ham bands as well. These are considerably more complex radios to operate and although able to exactly match the EU standard that is soon to be introduced, they will be non-compliant and therefore technically illegal for non licensed use. Some of these units will support Morse Code ( CW) which will increase range even further.
As a base station vertical antennas designed for vehicle use can be small and relatively unobtrusive For best range we have to install 5m long horizontal wire antenna or 2.5m tall vertical.
All versions of this type of radio will be Inter operable with the unknown number of existing CB FM stations in UK as well as the considerable number of pirate Freeband stations already in existence. The non-compliant versions can be interoperable with Ham 10m and 12m bands.
As a base station, more frequent but still occasional conditions will support communications out to 1000km range and on occasion inter-continentally as well.
Ham NVIS
Currently only legally usable by licensed radio amateurs.
Most complex equipment to set up and operate.
By far the greatest UK mainland coverage, and can be expected to have lowest energy consumption. 5w to 10w should be sufficient for good coverage. Just a dozen strategically located stations operating this equipment will be able to network cover the whole of the UK mainland. Unlike all of the previous options, NVIS transmissions will penetrate into deep valleys and heavily wooded terrain.
Transmitters are recommended are the size of CB vehicle mobile units, although there are also a number of hand held and portable radios on the market. However very small, simple and low cost low power Morse Code transceivers can be used effectively here…these are very robust, easy to power and easy to store as they are truly tiny ( sardine tin sized). See http://www.qsl.net/sp5ddj/pixie3.htm
For true NVIS operation, along with its greater reliable range antennas are very large and are really only fixed base installations. There are ways of taking these portable, but this becomes a somewhat specialised activity that most hams do no attempt.
For keeping a survival community of nationally dispersed fixed homesteads and retreats connected, this format offers strongest performance. Additional benefit to such a community is that transmissions can be received on fairly simple transistorised portable receivers, so that even remote locations can listen in ( big antennas are not needed for listening)
By investing in good ham equipment it is possible to have a single radio that will be interoperable with PMR446, Ham 2m/70cm handhelds like the UV5r, CB radio of both FM and SSB versions, as well as all of the Ham bands including the NVIS frequencies of interest. One very popular self -contained, paperback book sized radio is Yaesu’s model FT817 see brochure pdf at http://www.yaesu.com/indexVS.cfm?cmd=Dis...B4DC9C0D27
Conclusion
For flexibility and ultra portability the PMR446 capable Ham HT ( UV5r type) equipment is best . Cost around £30.00 but time and effort is needed to learn how to configure and use this equipment.
For most cost effective local region communications , the SSB capable CB system offers a good license free platform that can be set up, configured and experimented with in the near future. SSB CB does not replace the Ham HT equipment, it supplements it. Cost expected to be around £150.00 inc antenna.
For ultimate coverage and flexibility a Multi-mode Ham rig capable of operating on the NVIS Ham bands is best. Cost around £600 And for the same, but on a tight budget and with greatest long term durability and repairability in mind, ham band micro transceivers operating on the NVIS frequencies could prove great long term survival coms tools. Cost £10 to £120
The calculation is an under estimate as it does not take account of ground topology, nor the elongated shape of the UK
Ranges used are fairly typical for each class of radio.
Land area of UK is 243,610 Sq Km
PMR 446 Ave range =1.5km Number of stations to cover UK: 34,500
Ham HT UV5r type Ave range = 6.0km Number of stations to cover UK: 2,200
As base stn Avg range =20 km Number of stations to cover UK: 200
CB ( Fm) Ave Range = 8 km Number of stations to cover UK: 1300
As base stn Avg range =20 km Number of stations to cover UK: 200
CB ( SSB) Ave Range = 15km Number of stations to cover UK: 350
As base stn Avg range =30 km Number of stations to cover UK: 90
Ham NVIS Ave Range =100km Number of stations to cover UK: 12
Evaluation:
PMR446
More than 34,000 stations needed for national coverage!
Simple to operate. No antenna set-up issues, but CTCSS features complicate things somewhat.
Only useful for tactical and portable LOCAL communications. Not suitable for inter-survivor communications between dispersed fixed groups.
Huge number in circulation in the community: These will be scavengable items post event as many will be discarded once their power packs are depleted.
UV5r type Handhelds
Complex to set up and operate.
16x the coverage of PMR446. Suitable for tactical and portable local communications. Capable of inter village comms between fixed stations.
As a base station vertical antennas designed for vehicle use are small and relatively unobtrusive
Inter operable with PMR446, the 67,000 ham operators currently registered in the UK
Inter operable with maritime stations, coast guard and rescue services.
CB FM
The most simple radios to operate, although setting up antennas needs some skill and knowledge ( hand held units with built in antennas overcome even this)
28x the coverage of PMR446. Suitable for tactical local communications. Capable of inter village comms between fixed stations. Mainly designed for motor vehicle installation but these units are relatively small and can be made portable by constructing Man packs. Some hand held versions available ( Intek for ex)
As a base station vertical antennas designed for vehicle use can be small and relatively unobtrusive For best range we have to install 5m long horizontal wire antenna or 2.5m tall vertical.
Inter operable with an unknown number of existing CB stations in UK. As a base station, occasionally conditions will support communications out to 1000km range, but this is nor a reliable feature.
CB SSB
This is the 12watt EU standard that is soon to be legalised for license free use in the UK.
More complex to operate than normal CB, but too mush so, with identical antenna set up requirements
100x the coverage of PMR446, and 6 to 30 times the coverage of FM CB. Suitable for tactical and near region community communications between portable, mobile and fixed stations. Mainly designed for motor vehicle installation, these units are larger than hand helds, but can be made portable by constructing Man packs. Some self-contained hand held versions are available for portable use ( Albrecht for ex)
Versions of this type of radio are available that feature variable power, which is very useful as it allows us to use just enough power to make the contact, whispering, so to speak as opposed to shouting and drawing too much attention to us. Extended frequency range radios are also available that cover not just UK licensed CB frequencies but those of USA as well. In addition many of this class of radio will operate on two Ham bands as well. These are considerably more complex radios to operate and although able to exactly match the EU standard that is soon to be introduced, they will be non-compliant and therefore technically illegal for non licensed use. Some of these units will support Morse Code ( CW) which will increase range even further.
As a base station vertical antennas designed for vehicle use can be small and relatively unobtrusive For best range we have to install 5m long horizontal wire antenna or 2.5m tall vertical.
All versions of this type of radio will be Inter operable with the unknown number of existing CB FM stations in UK as well as the considerable number of pirate Freeband stations already in existence. The non-compliant versions can be interoperable with Ham 10m and 12m bands.
As a base station, more frequent but still occasional conditions will support communications out to 1000km range and on occasion inter-continentally as well.
Ham NVIS
Currently only legally usable by licensed radio amateurs.
Most complex equipment to set up and operate.
By far the greatest UK mainland coverage, and can be expected to have lowest energy consumption. 5w to 10w should be sufficient for good coverage. Just a dozen strategically located stations operating this equipment will be able to network cover the whole of the UK mainland. Unlike all of the previous options, NVIS transmissions will penetrate into deep valleys and heavily wooded terrain.
Transmitters are recommended are the size of CB vehicle mobile units, although there are also a number of hand held and portable radios on the market. However very small, simple and low cost low power Morse Code transceivers can be used effectively here…these are very robust, easy to power and easy to store as they are truly tiny ( sardine tin sized). See http://www.qsl.net/sp5ddj/pixie3.htm
For true NVIS operation, along with its greater reliable range antennas are very large and are really only fixed base installations. There are ways of taking these portable, but this becomes a somewhat specialised activity that most hams do no attempt.
For keeping a survival community of nationally dispersed fixed homesteads and retreats connected, this format offers strongest performance. Additional benefit to such a community is that transmissions can be received on fairly simple transistorised portable receivers, so that even remote locations can listen in ( big antennas are not needed for listening)
By investing in good ham equipment it is possible to have a single radio that will be interoperable with PMR446, Ham 2m/70cm handhelds like the UV5r, CB radio of both FM and SSB versions, as well as all of the Ham bands including the NVIS frequencies of interest. One very popular self -contained, paperback book sized radio is Yaesu’s model FT817 see brochure pdf at http://www.yaesu.com/indexVS.cfm?cmd=Dis...B4DC9C0D27
Conclusion
For flexibility and ultra portability the PMR446 capable Ham HT ( UV5r type) equipment is best . Cost around £30.00 but time and effort is needed to learn how to configure and use this equipment.
For most cost effective local region communications , the SSB capable CB system offers a good license free platform that can be set up, configured and experimented with in the near future. SSB CB does not replace the Ham HT equipment, it supplements it. Cost expected to be around £150.00 inc antenna.
For ultimate coverage and flexibility a Multi-mode Ham rig capable of operating on the NVIS Ham bands is best. Cost around £600 And for the same, but on a tight budget and with greatest long term durability and repairability in mind, ham band micro transceivers operating on the NVIS frequencies could prove great long term survival coms tools. Cost £10 to £120