Updated: 01 APR 17 Articles CONTACT! RGHQ-51 Military Reference Pages		Radio Voice Procedures 8. Radio Frequencies

The RTO's Page The RTO's Wiki Links Page 1 Introduction & Equipment. 2 Basic Radio Operations - includes useful learning aids. 3 NATO Phonetic Code 4 Prowords 5 FIVE BY FIVE 6 Authentication Codes 7 Message Precedence 8 Radio Frequencies The Profanity Codes ARAN

Introduction The radio frequency portion of the electromagnetic spectrum is divided in to a number of bands defined by wavelength. However, only three concern the UNMC (UNSGC); High Frequency (HF), Very Hhigh Frequency (VHF), and Ultra High Frequency (UHF). See Table 1 below. Most operators will only be using the Squad level radio network for Marine to Marine communications. This is in the 446MHz frequency range, which is part of the UHF band, see Table 2. While specialist RTO'S (Radio Telephony Operators), will use all 3 bands for unit to unit, and unit to base, as well as Marine to Marine communications. See Table 3 [TBA]. Wavelength, as opposed to frequency is important to know, as this is what determines the length of an antenna. Whip type antennas typically used on battlefield equipment tend to be either full-wave, half-wave, or quarter-wave length. In practise the "length" of the antenna can be electronically tweaked to reduce size, but usually at the cost of performance. The length for a PMR446 antenna would be either; 66cm (full-wave), 33cm (half-wave), or most often 16.5cm (quarter-wave). Table 1: The Bands Band Wavelength Frequency Range Range HF 100~10m 3~30MHz Long Range (over the horizon, over obsticles like hills, potentially global*) VHF 10~1m 30~300MHz Medium Range (line of sight to the horizon, blocked by hills, 500m~70km*) UHF 1~0.1m (100~10cm) 300~3,000MHz (3GHz) Short Range (line of sight, blocked by hills, 100m~8km*) * Dependent upon power output and antenna type. The PMR& dPMR Service Listed below are the 16 analogue PMR and 32 digital dPMR, or Private Mobile Radio frequencies that will be in service with the UNMC for its Squad level radio network as of 01 JAN 18. Both the analog PMR446 and digital dPMR446 radios operate in the frequencies between 446.0~446.2 MHz, which is in the lower part of the UHF band. Their output is 500mW. This means that they operate as line-of-sight radios, with limited ability to deal with obsticles like buildings and dense foliage. Hills and the like will completely block the signals. However for use within an SG Team, even with only 500mW of power, they are more than adequate for Marine to Marine communications. In fact these radios are significantly supperior in performance to the British Army's Personal Role Radios, that operate at a much higher frequency, with no more than 100mW of output. So for once our SG Teams have not been short changed by the supply chain. These radios come in two modes, analogue and digital. The former has been in service with the Corps for nearly two decades, but the digital kit has yet to enter service. Theoretically, they should give longer range, with supperior sound quality. Each of the analogue frequencies has 38 CTCSS (Continuous Tone-Coded Squelch System) "privacy" codes, while the digital service has 104 DCS (Digital-Coded Squelch) codes, aka ID codes. These codes enable users to exchange signals on the same frequency without over-hearing one another. Note that some radios have the option to broadcast without the use of a CTCSS or DCS code (usually marked "00" or "000"), in which case all 38 or 104 channels within a frequency can be covered similtainiously, which tends to provide better performance, especially in the analogue service. Using CTCSS the analogue service can provide up to 608 'channels', whereas digital radios using DCS can provide up to 3,268. Many of the new dPMR radios actually offer both analogue and digital output, meaning you have 48 frequencies, providing 3,936 'channels'. Be aware that although all makes of radio use the same frequencies, the numerical labels for these and for their CTCSS and DCS codes, do not always match one another. Care must be taken to make allowances for this possible flaw when selecting frequencies and codes prior to a mission. If there is no local interference, then do not use the CTCSS or DCS codes, and just specify the frequencies. You will need to learn which 'channels' correspond to which frequencies for your radio if different, and note these in your Battle Book. Some operators print this data on to a label, lamenate it, and affix it to the case of their radio. In the future so as to avoid this problem, the intention is that when equipment requires replacement, that a specific make and model of radio is selected for squad level service, and that any subsequent replacements matches the new legacy kit. dPMR446 equipment also has the advantage that it can support simultaneous voice and embedded data, text messages (SMS) and automatic GPS position reporting. However, to use many of these features requires a radio with a display and keypad, which in most cases will compromise its Ingress Protection (IP) dust and water resistance rating. FYI radios without keypads and displays, have a built in technique for programming them without their aid, but are mainly intended to be programmed by a computer prior to service. For the analogue service the frequencies are spaced at 0.01250 MHz (aka 12.5 kHz) intervals as set out below, whereas they are spaced at 0.00625 MHz (aka 6.25 kHZ) for the digital service. Expressing Frequency & CTCSS/DCS Codes In preparation for combat, radios will be pre-set to specified radio frequencies and DCS/CTCSS codes, which in turn will be allocated a single channel number. This number should be chosen so it does not indicate in any way the actual frequency or DCS/CTCSS code. Thus when in combat, and you suspect that the enemy is listening in, you can order a change to a different channel number, and it will take some time for the enemy to relocate your transmissions. However, there will be many times when this simply will not work, in which case you can specify frequency and codes openly. To make these frequencies easier to remember and articulate, it is not necessary to give the entire string. For example the following shorthand message can only ever apply to one particular frequency and code set, in this case part of the digital service: "KILO THREE ONE, KILO THREE ONE, THIS IS KILO ACTUAL, ADVISE CALLSIGN KILO TWO THREE, THAT THEY ARE JAMMING FREQ ONE FOUR, SIX EIGHT, DELTA THREE SIX, OVER" Firstly the frequency itself has been abbreviated from its full nine digit expression of "446.146875" MHz down to just "1468". This can be done because all frequencies in this band operate within 446.0~446.2MHz, and all end with either "25" or "75", but the middle digits are in fact sufficient to distinguish one frequency from another, if there is any doubt, simpley add the "2" or "7", as the final "5" can always be assumed. Analogue frequencies can be expressed as a single 3 digit group, while digital ones are expressed as two pairs. But bare in mind that sometimes it is necessary to give the entire frequency, especially in briefings, or in formal communications that are being recorded or written down. Secondly, the DCS code has been abbreviated to just "DELTA THREE SIX", by omitting the "CS" characters for speed. Likewise in the analogue service you would leave off the "TCSS" of "CTCSS", simply prefixing the code number with just "CHARLIE" to make it clear that this was a CTCSS code and not a digital one. BLANK Table 2: PMR & dPMR Frequencies IMPORTAN! 1. The suffix "A" and "D" for Analog and Digital in the following table is our own unofficial covention, enabling us to distinguish the two "channel" sets. 2. Frequencies A09~A16, and D01~D16 (marked in red) are NOT authorised for use until 01 JAN 18. In current, none upgraded equipment Channels D17~D32 are labelled as "Channels 01~16". This is because until 01 JAN 18, analog mode is restricted to 446.0~446.1, and digital mode to 446.1~446.2, thereafter their range has been overlapped, thus doubling the number of available frequencies. 3. As a reminder that for ease of use the optional figures have been placed within a pair of brackets, and the critical verbal expressions have been highlighted in bold. Analogue PMR446 Frequencies A01 446.006250 MHz "(FOUR FOUR SIX DECIMAL,) ZERO ZERO SIX, (TWO FIVE ZERO)" A02 446.018750 MHz "(FOUR FOUR SIX DECIMAL,) ZERO ONE EIGHT, (SEVEN FIVE ZERO)" A03 446.031250 MHz "(FOUR FOUR SIX DECIMAL,,) ZERO THREE ONE, (TWO FIVE ZERO)" A04 446.043750 MHz "(FOUR FOUR SIX DECIMAL,) ZERO FOUR THREE, (SEVEN FIVE ZERO)" A05 446.056250 MHz "(FOUR FOUR SIX DECIMAL,) ZERO FIVE SIX, (TWO FIVE ZERO)" A06 446.068750 MHz "(FOUR FOUR SIX DECIMAL,) ZERO SIX EIGHT, (SEVEN FIVE ZERO)" A07 446.081250 MHz "(FOUR FOUR SIX DECIMAL,) ZERO EIGHT ONE, (TWO FIVE ZERO)" A08 446.093750 MHz "(FOUR FOUR SIX DECIMAL,) ZERO NINER THREE, (SEVEN FIVE ZERO)" A09 446.106250 MHz "(FOUR FOUR SIX DECIMAL,) ONE ZERO SIX, (TWO FIVE ZERO)" A10 446.118750 MHz "(FOUR FOUR SIX DECIMAL,) ONE ONE EIGHT, (SEVEN FIVE ZERO)" A11 446.131250 MHz "(FOUR FOUR SIX DECIMAL,) ONE THREE ONE, (TWO FIVE ZERO)" A12 446.143750 MHz "(FOUR FOUR SIX DECIMAL,) ONE FOUR THREE, (SEVEN FIVE ZERO)" A13 446.156250 MHz "(FOUR FOUR SIX DECIMAL,) ONE FIVE SIX, (TWO FIVE ZERO)" A14 446.168750 MHz "(FOUR FOUR SIX DECIMAL,) ONE SIX EIGHT, (SEVEN FIVE ZERO)" A15 446.181250 MHz "(FOUR FOUR SIX DECIMAL,) ONE EIGHT ONE, (TWO FIVE ZERO)" A16 446.193750 MHz "(FOUR FOUR SIX DECIMAL,) ONE NINER THREE, (SEVEN FIVE ZERO)" Digital dPMR446 Frequencies D01 446.003125 MHz "(FOUR FOUR SIX DECIMAL,) ZERO ZERO, THREE ONE, (TWO FIVE)" D02 446.009375 MHz "(FOUR FOUR SIX DECIMAL,) ZERO ZERO, NINER THREE, (SEVEN FIVE)" D03 446.015625 MHz "(FOUR FOUR SIX DECIMAL,) ZERO ONE, FIVE SIX, (TWO FIVE)" D04 446.021875 MHz "(FOUR FOUR SIX DECIMAL,) ZERO TWO, ONE EIGHT, (SEVEN FIVE)" D05 446.028125 MHz "(FOUR FOUR SIX DECIMAL,) ZERO TWO, EIGHT ONE, (TWO FIVE)" D06 446.034375 MHz "(FOUR FOUR SIX DECIMAL,) ZERO THREE, FOUR THREE, (SEVEN FIVE)" D07 446.040625 MHz "(FOUR FOUR SIX DECIMAL,) ZERO FOUR, ZERO SIX, (TWO FIVE)" D08 446.046875 MHz "(FOUR FOUR SIX DECIMAL,) ZERO FOUR, SIX EIGHT, (SEVEN FIVE)" D09 446.053125 MHz "(FOUR FOUR SIX DECIMAL,) ZERO FIVE, THREE ONE, (TWO FIVE)" D10 446.059375 MHz "(FOUR FOUR SIX DECIMAL,) ZERO FIVE, NINER THREE, (SEVEN FIVE)" D11 446.065625 MHz "(FOUR FOUR SIX DECIMAL,) ZERO SIX, FIVE SIX, (TWO FIVE)" D12 446.071875 MHz "(FOUR FOUR SIX DECIMAL,) ZERO SEVEN, ONE EIGHT, (SEVEN FIVE)" D13 446.078125 MHz "(FOUR FOUR SIX DECIMAL,) ZERO SEVEN, EIGHT ONE, (TWO FIVE)" D14 446.084375 MHz "(FOUR FOUR SIX DECIMAL,) ZERO EIGHT, FOUR THREE, (SEVEN FIVE)" D15 446.090625 MHz "(FOUR FOUR SIX DECIMAL,) ZERO NINER, ZERO SIX, (TWO FIVE)" D16 446.096875 MHz "(FOUR FOUR SIX DECIMAL,) ZERO NINER, SIX EIGHT, (SEVEN FIVE)" D17 (CH01) 446.103125 MHz "(FOUR FOUR SIX DECIMAL,) ONE ZERO, THREE ONE, (TWO FIVE)" D18 (CH02) 446.109375 MHz "(FOUR FOUR SIX DECIMAL,) ONE ZERO, NINER THREE, (SEVEN FIVE)" D19 (CH03) 446.115625 MHz "(FOUR FOUR SIX DECIMAL,) ONE ONE, FIVE SIX, (TWO FIVE)" D20 (CH04) 446.121875 MHz "(FOUR FOUR SIX DECIMAL,) ONE TWO, ONE EIGHT, (SEVEN FIVE)" D21 (CH05) 446.128125 MHz "(FOUR FOUR SIX DECIMAL,) ONE TWO, EIGHT ONE, (TWO FIVE)" D22 (CH06) 446.134375 MHz "(FOUR FOUR SIX DECIMAL,) ONE THREE, FOUR THREE, (SEVEN FIVE)" D23 (CH07) 446.140625 MHz "(FOUR FOUR SIX DECIMAL,) ONE FOUR, ZERO SIX, (TWO FIVE)" D24 (CH08) 446.146875 MHz "(FOUR FOUR SIX DECIMAL,) ONE FOUR, SIX EIGHT, (SEVEN FIVE)" D25 (CH09) 446.153125 MHz "(FOUR FOUR SIX DECIMAL,) ONE FIVE, THREE ONE, (TWO FIVE)" D26 (CH10) 446.159375 MHz "(FOUR FOUR SIX DECIMAL,) ONE FIVE, NINER THREE, (SEVEN FIVE)" D27 (CH11) 446.165625 MHz "(FOUR FOUR SIX DECIMAL,) ONE SIX, FIVE SIX, (TWO FIVE)" D28 (CH12) 446.171875 MHz "(FOUR FOUR SIX DECIMAL,) ONE SEVEN, ONE EIGHT, (SEVEN FIVE)" D29 (CH13) 446.178125 MHz "(FOUR FOUR SIX DECIMAL,) ONE SEVEN, EIGHT ONE, (TWO FIVE)" D30 (CH14) 446.184375 MHz "(FOUR FOUR SIX DECIMAL,) ONE EIGHT, FOUR THREE, (SEVEN FIVE)" D31 (CH15) 446.190625 MHz "(FOUR FOUR SIX DECIMAL,) ONE NINER, ZERO SIX, (TWO FIVE)" D32 (CH16) 446.196875 MHz "(FOUR FOUR SIX DECIMAL,) ONE NINER, SIX EIGHT, (SEVEN FIVE)" BLANK HF, VHF & UHF Services This equipment is used for base stations, vehicle mounts and backpack radios, and are operated by highly trained specialist Radio Telephony Operators (RTO'S). The basic systems, operated by Class F RTO's will produce somewhere between 5~10W of output, which with appropriate antennas should be able to cover the entire current AO (Area of Operations). The three Classes of RTO's are authorised to use peak power outputs of up to: Class F RTO (Foundation Licence): 10W ERP Class I RTO (Intermediate Licence): 50W ERP Class A RTO ("Advanced", aka Full Licence): 400W ERP W = Watts (power output) ERP = Effective Radiated Power (radio output + antenna gain) Precise frequencies and performance are still subject to the outcome of the training program, and we do not yet know when these services will become available, although it is hoped to arive sometime later this year (2017). Watch this space. NB: Table 3 will be added once the new operators and their equipment come on line. Table 3: TBA BLANK End of Document

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