Call Sign Formats
Broadcast Stations of the World

 Types of Call Signs

 KDKA  LKA  Z2AB  T3K   3AM   9RLV

This is the most common form of call sign. The 3-letter format dominates in Europe while the 4-letter format dominates in the Americas. Some countries allow even longer call signs such as XEABC Mexico City, TIRSCLCH Los Chiles, Costa Rica, etc. In some countries, letter-number or number-letter prefixes also exist.

The call sign consists of the ITU-assigned country prefix followed by a unique set of letters. In the main examples above : K-DKA, LK-A, Z2-AB, T3-K, 3A-M and 9R-LV. In many cases the additional letters have meaning, in other cases they don't. For government stations, the additional letters assigned were often abbreviations for cities, such as OKP Prague and OKB Brno, Czechoslovakia or 9RLV Leopoldville, Congo. For commercial stations, the additional letters were often company abbreviations, such as WBEN Buffalo, USA for the Buffalo Evening News newspaper. In some countries, the 3rd letter can indicate the region within the country; for example in CMEA Santa Clara, Cuba, the E indicates Villa Clara Province.



This format was adopted by many countries for their broadcast stations and is the same one assigned to amateur radio stations. The number following the prefix usually indicates the region within the country (although in the Italian I2RO example, the 2 indicates the 2nd gov't station in Rome). Since these call signs tended to be more cumbersome to use over the airwaves versus simple 3 or 4-letter calls, they were often truncated, leaving the first one or two letters off. For instance, in the first few examples "2AB"  "2LO"  "7LO"  and "2RO" were used over the air in lieu of the full official callsign. Because of this practice and because of the lack of access to official publications in the early days of radio, DXers have often made the assumption that these truncated callsigns were the actual official ones.

Over time, some countries such as Australia *have* actually made the truncated calls the official ones, at least in the mediumwave band. It is encouraged to continue using the fully prefixed call for international MW DX reports, even though the previously "de facto" calls are now "de jure".



The HC series used in Ecuador for radio stations is a variation of the amateur service format where characters are transposed. Rather than HC2AB, for example, the call sign appears as HCAB2. The OA series used in Peru is another example, where OA2XA becomes OAX2A.


 LRF234  ZYA567

This format has been adopted by a few countries and is the same one assigned to fixed service (point-to-point) radio stations. Often, the 3rd letter signifies a region of the country.


 CSA2  EAJ34  RW567

This format consists of a group of letters followed by a number, usually starting with 1 or 20 and advancing sequentially with each new station assigned. In some countries, this group of letters is simply an ITU prefix, while in others it may be letters assigned to a particular region, type of licence or radio company. Sequential call signs were first adopted by Switzerland, with HB1 Geneva and HB2 Lausanne as the first two licensed stations. Switzerland later abandoned this format. Today, Russia is the biggest user with its RW stations.


 CD56  4QQ218  DMQ-6  HCEE2

This format includes abbreviated frequency information within the call sign. In the first two examples above, 560 kHz and 21.8 MHz are the frequencies of the stations with these call signs, while DMQ-6 is in the 6 MHz band. In the HCEE2 example, this is a TV station in Ecuador operating on channel 2.


 OLR-2A  OEI-34

This format includes coded band information within the call sign. In the first examples, the primary call sign is OLR, the 2 indicates the shortwave band (2 = 49 metres, 3 = 31 metres, 4 = 25 metres, etc.), while the A is the sequential assignment within that band. In the 2nd example, OEI is the primary call sign, the 3 indicates the band (2 = 49 metres, 3 = 41 metres, 4 = 31 metres, etc.), while the 4 is the sequential assignment within that band.


 HV2  HV5  HV100

This format is used in Vatican City on MW. The numeral indicates the power of the transmitter in kW. HV2 = 2 kW, HV5 = 5 kW and HV100 = 100 kW. (Of note, the powers of HV2 and HV100 have increased since the call signs were assigned.)


 VUA2  CD55A  CBF-1

A numerical suffix can either indicate an additional station in the call sign series (example : VUA Ahmadabad, VUA2 Amritsar, VUA3 Allahabad, etc.), an additional station on the same frequency in the frequency series ( CD55, CD55A, CD55B, etc.) or a relay station (CBF Montreal, CBF-1 Senneterre, CBF-2 Mont-Brun, etc.). The numerically suffixed call sign appears similar to the sequential call sign format, however it is different due to the fact that it used for only a minority of stations within a country rather than all of the stations.


Many countries have changed call sign formats over the years. The Dominican Republic is one recent example, changing from the conventional 4-letter call sign format to the sequential format.

Some countries, such as Canada, have used prefixes that belong to other countries - assumedly with permission. In Canada's case, most government radio stations begin with the prefix "CB", which is assigned to and also used by Chile. As a result, there are duplicate call signs such as CBA Moncton and CBA Arica, CBV Quebec and CBV Valparaiso, etc.

Some countries, such as The Bahamas, continue to use old callsign prefixes that are no longer assigned to them. In this case, the prefix "ZN", which is assigned to the British Colonies, a group to which The Bahamas no longer belongs.

Psuedo "call signs" that do not use the official ITU international prefixes and instead are network abbreviations, such as "KBC" Kenya, "BRT" Belgium, "RTM" Morocco, etc., are not included in the DX Info Centre call sign lists. The ITU's International Frequency List (IFL) used to flag these types of calls with a ** symbol, indicating that they were an "identification" rather than "call sign". This is no longer done in the IFL, but some national frequency lists, such as the Canadian one, continue to use this methodology when listing things such as radio beacon "identifications" in lieu of call signs. There are a few exceptions for countries whose official call signs are a mix of traditional and psuedo-type call signs. Spain is an example, with "RNE" being assigned to government stations.

The ITU maintains 27.5 MHz as a division between international and national frequency assignments. Therefore, we recommend the acceptance of non-standard or truncated ITU prefixes (such as Australia's) as the dx call signs for broadcast stations above 27.5 MHz. The vast majority of the world's stations above 27.5 MHz are not assigned call signs using the international call sign series, but rather use national conventions that vary from country to country. So, 2ABCRR (rather than VL2ABCRR) and ABNQ in Australia are perfectly acceptable - and for a large portion of the world's VHF stations, no call signs are assigned whatsoever.

RW or RV ?
Lists of Russian stations will often swap between RW and RV for the call sign prefix. Which is correct?
If you transliterate from Cyrillic to Latin using the ISO 9 standard, the Cyrillic PB becomes RV in English. There are no Cyrillic letters that transliterate as W. However in German and Polish, PB does transliterate as RW.

One question we must ask is which character set is the original call sign assigned in - Cyrillic or Latin? One would assume Cyrillic - however we know that the ITU uses the Latin alphabet exclusively for its call sign allocations, so are the call signs assigned using Latin characters only?  Is RW in fact transliterated as PB rather than the other way around?

To break this deadlock, I have decided to let the ITU decide. In the IFL, the ITU uses RW as the prefix for Russian stations, although RV is used in some of the former Soviet republics. The ITU version is the one that I will consider official and is the one that you will see in use here.

Back to :   Call Sign List    SW Call Sign List    DX Info Centre
©2010-12 William R. Hepburn