Bill's Radio Site

Call Letter and Radio HIstory Page

Last updated November 27 2010  

I have always been for some reason fascinated by call letters.    I have assembled here a combination of pages I myself have written as well as links to various external lists and to historical pages that go well beyond call letters.      I commenced working on these pages in 2008, worked on them for a few months, and as of 2010 they are sitting here unfinished and not well organized.   Hopefully you will find some of this interesting even in the form it is in today.

Some links and references to radio history and reference pages and publications that I have used and plan to use in writing my own pages or  have just plain enjoyed, and which you may find interesting.

Spud Roscoe, VE1BC, has provided me with lists and clarifications of various kinds.  His wonderful and extensive historical account is entitled "Radio Stations Common? Not This Kind".   This is a .pdf file of several chapters and includes many many photographs.  This is essentially the story of Canada's coast radio system and of marine radio, both civil and naval.    This site from a veteran radio operator has to be seen!  

Also extremely important is Jerry Proc's extensive site on Canada's naval radio history: Radio Communications and Signals Intelligence in the Canadian Navy.   This covers both land and shipboard radio.  While I am not dealing specifically with ship callsigns here on my site, those who are interested will find a huge list of Canadian naval ships and their callsigns, both the international type and the tactical voice type, and is up to the minute.     Like Spud's site, this is a great source of information on call signs, equipment, procedures, and just wonderful history.

From the west coast comes Rough Radio: History of Wireless Along the British Columbia Coast, written by Jack Statham, VE7VAZ.   


Statistics Canada's "Coast stations for communication by wireless telegraphy with ships at sea, fiscal year 1916"

Statistics Canada's table "Wireless and radio stations in operation in Canada, March 31, 1924 to 1927

Statistics Canada's table "Radio stations in operation, by class, as at March 31, 1942 to 1946"

In general the excellent website United States Early Radio History.  There is a secton devoted to the early international conferences that brought about regulations and call letters. The US Navy lists linked individually below are on this site.

List of Wireless Telegraph Stations of the World, including shore stations, Merchant Vessels, Revenue Cutters and vessels of the United States Navy, corrected to October 1, 1910   United States Department of the Navy, Bureau of Steam Engineering (facsimile reproduction on this site)

Wireless Telegraph Stations of the World, as the preceding, corrected to January 1, 1912

I also used Bill Hepburn's list of Continuous Marine Broadcasts in Canada.  This excellent list does in effect show all the active call signs for Canadian Coast Guard radio stations including all the peripheral transmitters.  It shows clearly that there really are very few 3-letter calls in use any more outside the military.

Another excellent site with links to various Canadian Army Signals historical pages is one entitled RCSigs Militaria.  This site includes a link to Major  John MacKenzie's 90 Years and Counting: The History of Canadian Military Communications and Electronics.

The Communications Security Establishment: Canada's Signals Intelligence Agency This appears to be an unofficial site on Canada's SIGINT establishment.  Contains links to related sites.

See the Hammond Museum of Radio for the history of radio in Canada, including radio apparatus built in this country.

The Troy Wood site has pages on the Vancouver Wireless Station, CFS Massett, Alert and various military communications and SIGINT stations, and links to other military communications sites.

The Camp X Historical Society website is on Canada's spy training camp in Ontario during World War II, supported by Oshawa Wireless Station.

The United States Early Radio History from Thomas H. White is also fascinating, and gives amongst other things a good outline of the early days of radio when the marine service was paramount, and as well contains several official lists of stations and call letters.   This is a huge site that also deals as much with early broadcasting as it does other topics.  This is where I came to find out about the early international conferences that resulted in radio regulations and call letter allocations.   Included in this site is a reproduction of Wireless Telegraph Stations of the World, from the US Department of the Navy, corrected to January 1, 1912.  This includes the Canadian stations, which at that time were using the Marconi call letters.   White's site has a large number of links to other sites of interest.

I also consulted a publication I have had for more than 30 years, the Alphabetical List of Call Signs of Stations Other than Amateur Stations, Experimental Stations and Stations of the Maritime Mobile Service , 4th edition, January 1970.  International Telecommunications Union, Geneva, 1970.    I recall purchasing this in the early 70's direct from Switzerland, and that the payment was in Swiss francs.

Utility DX'ers Handbook. 1971. Steven Joel Handler and Paul Mayo.

Admiralty List of Radio Signals, Volume I, 1969.  Hydrographer of the (Royal) Navy, 1969.  This publication was also known within the service as N.P. 275 (I)

Radio Call Letters (as of May 9, 1913). Department of Commerce, Office of the Secretary, Washington, 1913.

Radio Navigational Aids 1943. United States Navy Department, Hydrographic Office, and known as H.O. 205.

Radiotelephone Directory of British Columbia, 1957 edition.   This publication lists all the ships registered in Canada that were operating on the west coast, along with their call letters.   It also details the ship/shore marine operator system then active in the 2 MHz and 4 MHz bands.   Interestingly there are also numerous isolated fishing camps and logging sites also listed as they used the marine radio system as well.

North American Radio-TV Station Guide , 2nd edition, 1964, and 10th edition 1974, Vane A. Jones.  This was a more formal version of the various lists that came out in magazine format in the 70's and earlier, such as White's Radio Log.   I used this to check on 3-letter call letters in use in Canada.

Some information is recollection from when I was a Communications Officer in Canada's navy in the mid-70's, or taken from various official lists and from unofficial websites, that I am now unable to cite properly.


American call sign form history

ITU regulations on call letters

ICAO's official site re nationality marks

ITU international allocation list

International Prefixes        


Inland Marine Radio History Archive (Mississippi/Great lakes) (some links below are direct to pages of IMRHA)

Map of Canadian coast stations Grt Lakes/St Lawrence area 1950

US Great Lakes Ship callsigns 1931

Canadian Grt Lakes Ships callsigns 1992

DX' re call letter prefixes

Links to other call letter pages that I myself am in the process of writing or constructing:


American 3-letter call signs.



For those who want more of an historical narrative, it is recommended that you go to the various websites mentioned below.

The information on these pages has come from or been inspired by a number of sources.  Some are official list publications.  These are dry but very interesting to look through.   The others mentioned are not just interesting, they are extremely fascinating, and I cannot thank the authors enough for writing these histories, which go far beyond lists.   Some history is also contained in my broadcasting pages at my main site:     You may also like to visit my pages about my own background in the radio hobby, and also see many of my QSL cards from my years of radio listening.


My intent here is to list as many three letter call signs in alphabetical order, with a bit of information about each station.   This is a slightly different twist on the subject and is quite bare compared to the richness of the above sites.   As the saying goes, "you simply MUST" visit these sites.  I enjoy them  very much.  Both Jerry and Spud have kindly responded personally to my queries, and I am sure they will be happy to answer your questions or receive any input you can give. 

Call letters are the combinations of letters and sometimes numbers that serve to identify a radio station.  Examples are GBR (coast station), VE7BBM (amateur radio station), XND301 (land fixed station),  C-FRDX (aircraft) and CHNS (broadcasting station).  I am including aircraft "registration marks" under the umbrella of call letters because most aircraft marks in the world outside the USA and Russia are in fact identical to call letters. 

"Call letters" can be included under the wider term "call sign" that also includes word identifications such as Speedbird 56 (identifying a commercial airline flight), Hanger 15 (identifying a military aircraft by unit and individual aircraft number), Blackball (identifying a particular military pilot rather than the aircraft itself), and other informal handles.  Logically these could also include the non-call letter identifiers commonly used by broadcasters, such as "The Wave" or "Q104.3" but I have never heard them referred to as call signs.

This page concerns call letters in particular and will concentrate on the Canadian system, which adheres very closely to the internationally mandated umbrella system.   In order to inject a little variety I will also be using the term "call sign" but unless I am referring to one of the other types, I will be referring only to call letters.

For some reason I have always been interested in call letters, and the organization of them internationally.  This comes from my innate interest in lists and organization. I have written short articles about call letters in the past, the distant past, but cannot find them at the present.  This informal page is a spot where over time I am going to post bits and pieces that I find or write about international call letters or call signs, especially Canadian ones.



SHIP SIGNAL FLAG IDENTIFIERS:  It is safe to say that the precursors of radio call letters were the signal flag identifications used by ships in the 19th century and before.   No doubt there were many different systems of a national nature, but apparently it was not until the mid 19th century that an international system of sorts came into use.     At that time ships that adhered to the system had four letters assigned, with naval and government ships receiving identifiers beginning with the letter G in the range GQBC to GWVT, and commercial vessels receiving identifiers in the range HBCD to WVTS.   [As an aside please note that in those days there were no vowels allowed as there were none in the flag system, nor could there be a repeat of a letter within an identifier   ---  thus in this latter series, HBCD is the first one possible!  Why those beginning with WX and WZ were not allowable I do not know]  To identify themselves they would hoist a 6 flag group commencing with the national flag at the top, followed by a flag indicating "code" and then the four letter flags of the call letters.     I am led to understand that the same four letter group could be assigned in various countries, as the overall signal would be prefaced by the national flag.  This system may have evolved to the point where other letter groups than those starting with G were possible.  Until the mid-1920's and beyond, these signal letters had nothing to to with radio call letters, but from that time onwards the two systems became one, in the sense that instead of two sets of identification letters, there was just one, and that conformed to the radio call letters.  Today the four letter flag identifiers are still used but mostly by naval ships and without the two preface flags, and no two ships have the same identifier.    Many naval ships have the four letter flags painted prominently on each side of the funnel or superstructure.   Some civilian vessels, especially fishing vessels, may have the call letters painted out as letters, not as signal flags. 

This page is not a history of radio itself, but it is important to note that conferences and conventions were held in Berlin in 1903 and 1906 respectively, and while these did not produce any binding international regulations, they were the start.  The first call letter assignments came out of the London conference in 1912.   The antecedent of today's ITU (International Telecommunications Union) was set up in Berne, Switzerland (where it remains today).  Between the 1912 conference and some tweaking by the Berne office, the first internationally sanctioned call letters appeared in 1913.   Prior to this there had been on-air identifications, including systematic ones.  For example, the coast and ship stations of the Marconi company had settled on 3-letter calls beginning with the letter M.    Those had replaced what mostly were 2-letter calls that often were indicative of location.  For example the Halifax station had been using HX, but that was replaced by MHX.    In the new international system coming on stream in 1913, those M calls disappeared.   M subsequently became a prefix for British stations only under the international system, so there may well have been an MHX in the new system but certainly not at Halifax!

The biggest user of call letters in 1913 and for quite some time were ships and coast stations.   The demand for call letters was not all that extensive, so that all call letters at first were of the 3-letter variety, whether a land station of some kind or a ship station.  The ship 3-letter call letters were of course different from the pre-existing 4-letter flag identifiers.   In time the 3-letter call signs were replaced by 4-letter ones and the two systems conformed to each other, but with the provision that the same 4-letter call could not be used in different countries, in accordance with the international protocol of the radio authorities.   The result was that the flag and radio identifiers became identical beginning in the 1920's.

The London conference and the Berne office allocated sets of letters to various countries.   Some of these allocations remain the same today but generally speaking there were quite a number of revisions made over the years prior to World War II, but since that time most changes have been the addition of prefixes for new countries that have come into existence.    To some extent, such as in the breakup of the Soviet Union, prefixes that already existed have been farmed out to new countries.

All countries have one or more prefixes assigned, and in theory at least, all call letters of stations in or of that country must start with an assigned prefix.  Prefix series are allocated by the International Telecommunications Union, a United Nations organization based in Switzerland.

National prefixes are made up of two characters.  At first they were all two letters in the series AA to ZZ, with the exception of QA to QZ.     Larger countries or more correctly, those with more clout internationally at the time, received complete single letter series, e.g. all the W's (United States) or all the I's (Italy, which means that the United States had (and still has) WA to WZ.    This also gave these lucky countries the latitude to also use call signs that commenced with just that first letter, followed by a number, e.g. W1 to W0.   Later when all the two-letter prefixes ran out, the ITU resorted to prefixes that were comprised of a letter followed by a number, such as A9, and the opposite type, such as 3B.   Of course as just stated, some countries already had de facto use of Letter/Number prefixes.

In time I will list or link to the complete list of current prefixes but for now here are a few of most interest. (this section is under construction)

Table of Allocations (under construction).   This table is a preliminary one.  It will only show for now the allocations that begin with two letters which was the original and only type until after World War II.   Later I will add the types that begin with a letter and number, and with a number and a letter.    This table will be unique I think in that I will include the 1913 allocations beside the "current" ones.   Back in 1913 not all the possible prefixes were allocated, but the big news is that many prefixes including complete single letter series like B were later moved from one country to another or split between several.  NOTE; AS OF 2010 I HAD STILL NOT BROUGHT THE CURRENT INFORMATION IN.  SOMEDAY!

Letter 1913 Group 1913 Assignment Current Group Assignment
A A (all) Germany
B B (all) United Kingdom
C CN Morocco
CO - CP Chile
CQ Monaco
CR to CT Portugal
CW Uruguay
D D (all) Germany
E EA to EG Spain
F F (all) France
G G (all) United Kingdom
H HA to HF Austria-Hungary & Bosnia-Herzegovina
HG to HH Siam
I I (all) Italy
J J (all) Japan
K KA to KC Germany
KD to KZ United States
L LA to LH Norway
LI to LR Argentina
LX to LZ Bulgaria
M M (all) United Kingdom
N N (all) United States
O OG to OM Austria-Hungary & Bosnia-Herzegovina
ON to OT Belgium
OU to OZ Denmark
P PA to PI Netherlands
PJ  Netherlands West Indies and Surinam
PK Netherlands East Indies
Q Q (all) reserved for service abbreviations
R R (all) Russia
S SA to SM Sweden
SN to ST Brazil
SU Egypt
SV to SZ Greece
T TA to TM Turkey
U UA to UM France
UN to UZ Austria-Hungary & Bosnia-Herzegovina
V VA to VG British Empire: Canada
VH to VK British Empire: Australia
VL to VM British Empire: New Zealand
VN British Empire: Union of South Africa
VO British Empire: Newfoundland
VP to VS British Empire: non autonomous colonies
VT to VW British Empire: British India
W W (all) United States
X XA to XC Mexico


Call Letter Usage

This is simply a general comment that call letters are becoming less and less used here in North America.   To the average person call letters were most apparent in radio broadcasting and all stations in Canada and the United States were required to have and use their call letters frequently.     These were mostly 4-letter call signs in the series KAAA to KZZZ , and WAAA to WZZZ in the United States, and in Canad those beginning with CF/CH/CJ/CK.    There were quite a few 3-letter ones as well in the USA issued in earlier days, and less than a handful in Canada.   None of the 3-letter type are now assigned.    When I was a kid, I and everyone else listened to AM radio a lot, and knew the stations by their call letters, such as CKLG, CKWX, CBU, and CFUN (which of course was pronounced as C-FUN).  Nowadays broadcasters, especially on the immensely popular FM band, are not required to state their call letters very often and listeners do not identify with them.  For example here in the Halifax area most of the FM stations do not use the call letters in their corporate identities or "personas", though some might have call letters that relate to the slogan that IS used.    KOOL-FM has the actual call letters CKUL-FM, but on the other hand HAL-FM has the call letters CHNS-FM. and CBC Radio 1 in Halifax is actually CBHA-FM.    The average person really has no knowledge of call letters any more.

Similarly, in scanning circles, they have also waned in importance.    As late as the early 90's it was common in the Halifax area to hear the police base station identify as XJF43 and the RCMP telecoms to identify as XJE416, but with the move to trunk radio the dispatcher is technically not even on a radio, except via the transmitter at one or more trunk sites so they just aren't used.    The trunk sites themselves have call letters but these are only transmitted on CW on occasion but are not actually heard by trunk users!   

Call letters have not been used much in international broadcasting in the last few decades.   For example the transmitters of Radio Canada International at Sackville, New Brunswick have the call letters CKCS but this is never used on air.   Similarly the Voice of  America and the BBC World Service do not use them.    In many countries the domestic broadcast stations do not use them.


Call Letter Form

This refers to how the call letters are put together, for example the prefix plus one letter to form a three character call sign such as CFH (Naval Radio Halifax) or something like 9YR or A1B.    There are also 4-letter call signs, 5-letter call signs, and many other forms as well.

Here is some of the basic pattern but individual countries do sometimes decide not to conform.   Where I refer to 3-letter for example, it more properly should be "International two-character prefix followed by a letter"

In addition to the forms mentioned here, there are also regulations and conventions regarding the use of various particular letters.   I hope to find the details to present here, but for example there might be a rule that says that there cannot be a a certain letter used as it might be confused with some other character.  As I said I need to find the details, but I know these do exist..


Type or Form Example(s) Description
2-letter then 1 or 2 digits CF3 Space service? base stations (I am uncertain about current usage... may have included any base stations transmitting via satellite bounce or relay ... nowadays there are many of these)
3-letter VCK, 9YR Coast (marine) stations,  Broadcasting stations*
4-letter  CFEP, CYCY Broadcasting stations*, Ship stations
5-letter CFABC Aircraft stations (which in effect means the aircraft themselves as registration marks.  These generally are painted with a hyphen following the first or second character, e.g. C-FABC).  In Canada, some subsidiary CBC television stations have 5-letter calls such as CBUCT.    The majority of countries use this format for their aircraft but quite a few do not.  See my aero call sign page.
2-letter followed by 4 digits CY2625 Ship stations.  This type has replaced the 4 letter type in some countries.   Very low power broadcasters in Canada also use this form.
3-letter followed by 1 digit  VFW5 coast stations or aeronautical ground stations
3-letter followed by 2 digits XJA44 coast stations or aeronautical ground stations or land fixed stations
3-letter followed by 3 digits XND301 land fixed stations
3 letters followed by 4 digits WPD3425 Ship stations, a recent necessity in some countries, notably the US
4 letters followed by 1 or two digits WXLG3 Originally this identified a lifeboat from the ship with the basic 4-letter call, but today some countries with many ships and few available call signs (so-called "flag of convenience" countries) use this form for the ships themselves, so that for example 6ZAB1 is a different Liberian ship than 6ZAB2.
2-letter followed by a single digit, followed in turn by 1 to 3 letters KL7X, VA1WW, VE1CBG Amateur radio stations.  Please note that countries holding a complete letter series can use a single letter at the beginning of amateur station calls, e.g. American N4GL or W4ABC, although in theory these are actually 4 letter and 5 letter call signs)  Confusing!
2-letter followed by 7? digits XM6310458 This is from memory, I believe this is the form taken by the old CB (GRS) call signs when the service was huge in Canada in the late 1970's.   The first one or two digits indicated the area of Canada.

* Broadcast stations basic call letters may in some cases be followed by a two letter suffix, such as FM, TV, DT, LP, etc.   These suffixes are generally shown following a hyphen, but this may not be official.   The question is, does a four letter basic call,  followed by a two letter suffix, constitute a 6-letter call sign?   I do not know the answer to this!    Example:  CJCH-TV   

Here in Canada we have further complications with our many satellite transmitters that rebroadcast another stations transmissions.  For example we could have CJCH-TV-6, to indicate a station that rebroadcasts CJCH-TV,  or CKZZ-FM-5 to denote what may be the fifth rebroadcaster of CKZZ-FM.   We could also have CKZZ-5-FM, which would indicate the fifth rebroadcaster of CKZZ (AM station) but this rebroadcaster is on FM!


Canadian Call Sign formation.  

This is from evidence as seen in published lists, not from any statement from official sources

3-letter call signs (Coast stations, Military and Broadcasting)

CF    Military land fixed stations
CG    Military land fixed stations
CH    Military land fixed stations
CI    Military land fixed stations
CJ    Military land fixed stations
CK    Military land fixed stations (except 3 broadcasting stations, 2 of which remain)
CY    Military land fixed stations
CZ    Military land fixed stations
VA    Dept of Transport Marine or Marineaeradio stations (now Coast Guard Radio stations)
VB    Dept of Transport Marine or Marineaeradio stations (now Coast Guard Radio stations)
VC    Dept of Transport Marine or Marineaeradio stations (now Coast Guard Radio stations)
VD    Dept of Transport Marine or Marineaeradio stations (now Coast Guard Radio stations)
VE    Military land fixed stations    
VF    Dept of Transport Marine or Marineaeradio stations (now Coast Guard Radio stations)
VG    formerly used for Dept of Transport light stations
VO    Newfoundland area coast stations, and possibly formerly also light stations
VX     Military land fixed stations   
VY    Military land fixed stations

There is no known use of the Canadian X series for three letter call signs.


4-letter call signs (Broadcasting and Ships)

CFXX    Broadcasting
CGXX    Ship Station (federally owned) [Some say there are blocks for various govt depts... I have not seen a pattern]
CHXX    Broadcasting
CIXX     Broadcasting  (much more recent implementation than the other broadcast series)
CJXX     Broadcasting
CKXX    Broadcasting
CYXX    Ship Station (CYAA to CYPZ is civilian.  CYQA to CYZZ is naval --  but I have seen a very few exceptions. e.g. HMCS Corrner Brook CYCB)
CZXX    Ship Station (Naval)
VAXX    Ship Station
VBXX    not seen
VCXX    Ship Station
VDXX    Ship Station
VEXX     not seen
VFXX     not seen
VGXX    Ship Station
VOXX    Ship Station and Broadcasting (Newfoundland connection)
VXXX    Ship Station
VYXX    Ship Station
XJXX     Ship Station
XKXX    not seen
XLXX    not seen
XMXX   not seen
XNXX   not seen
XOXX   not seen


2-letter followed by 4 digits (Ship and Broadcasting)

CFnnnn   Civilian vessels
CGnnnn  Federal government vessels
CHnnnn  Very low power non-rebroadcasting television stations
CYnnnn  Civilian vessels
CZnnnn   Civilian vessels
VBnnnn   Civilian vessels
VCnnnn   Civilian vessels
VFnnnn   Very low power non-rebroadcasting radio stations.
VOnnnn   Civilian vessels
VYnnnn   Civilian vessels

There is no known use of other C, V series, or of any X series.


CBxxT    Certain CBC tv stations.  It is thought that this use is inconsistent but may indicate a station that substantially rebroadcasts another but might have very limited individual programming such as insertion of local commercials.

CFxxx     Civilian aircraft (originally marked on a/c in form C-Fxxx, but new assignments are now C-Fxxx)
CGxxx    Civilian aircraft (marked on aircraft as C-Gxxx)
CHxxx    Hovercraft (this form was current in the 1970's as hovercraft were registered with aircraft at that time, but now apparently have a different form of identification similar to that of ships)
CIxxx     Ultralight aircraft  (might also include balloons) (does not include gliders, which are registered as regular aircraft)
VCxxx    Military aircraft (apparently no longer in use)
VDxxx    Military aircraft (apparently no longer in use)
VFxxx    Military aircraft (apparently no longer in use)