CTY.DAT Format

CTY.DAT is the format for CT Version 9. It includes more information than the .CTY files for previous versions of CT. This allows CT to calculate, in real time, beam heading and sun times. It also means that a single file can be used for all DX contests. The format is as follows. Note that the fields are aligned in columns and spaced out for readability only. It is the “:” at the end of each field that acts as a delimiter for that field:

Column Length Description
1 26 Country Name
27 5 CQ Zone
32 5 ITU Zone
37 5 2-letter continent abbreviation
42 9 Latitude in degrees, + for North
51 10 Longitude in degrees, + for West
61 9 Local time offset from GMT
70 6 Primary DXCC Prefix (A “*” preceding this prefix indicates that the country is on the DARC WAEDC list, and counts in CQ-sponsored contests, but not ARRL-sponsored contests).

Alias DXCC prefixes (including the primary one) follow on consecutive lines, separated by commas (,). Multiple lines are OK; a line to be continued should end with comma (,) though it’s not required. A semi-colon (;) terminates the last alias prefix in the list.

If an alias prefix is preceded by ‘=’, this indicates that the prefix is to be treated as a full callsign, i.e. must be an exact match.

The following special characters can be applied after an alias prefix:

(#) Override CQ Zone
[#] Override ITU Zone
<#/#> Override latitude/longitude
{aa} Override Continent
~#~ Override local time offset from GMT

See the examples on page 27 in the CT9 manual.

Important Information

A callsign can be associated with more than one entity in the file. 4U1VIC is one example. In the ARRL DX contests, for example, it counts for Austria, OE. In the CQWW contests, it counts as a unique multiplier, separate from Austria. See the information about “Primary DXCC Prefix” above. Software is expected to parse the file from top to bottom.  If a duplicate callsign is found, simply ignore it the second time.

Known Limitations

  • CT8 can override zones on a prefix basis, but can only override continents on a country basis. This doesn’t work in a few cases, notably IG9/IH9, which are in CQ Zone 33, and hence in Africa, but will be logged as Europe. Neither does it work for the part of Turkey that is in Europe – there is no way to just override the continent for the TA0 and TA1 prefixes. This is really only a problem for the IARU HF World Championship. In CQWW, the European part counts as a separate multiplier, hence CT gets the continent correct. In ARRL, contacts from W/VE are the same number of points whether Turkey is in Europe or Asia.This is not a problem in CT9, because you can now override the continent for a given prefix.
  • CT doesn’t handle prefixes such as FR5ZQ/J correctly. Listing FR/J as a prefix for Juan de Nova in the country file doesn’t work unless a station signs “FR/J” as his callsign. If you work one of these islands, you’ll have to add it to the country file manually. Otherwise “/J” will be logged as Japan, “/G” as England, “/T” as Reunion, and “/E” as an unknown prefix.