Tips on understanding CTY.Dat

This file is bundled in nearly every Ham radio software package you have ever used.

Obtaining

To get the latest version use this command

wget https://www.country-files.com/cty/cty.dat -O /tmp/cty.dat

You will probably want to place this somewhere sensible ... i.e.

cp /tmp/cty.dat /usr/local/share/cty.dat

View the file

Nice and Easy

This is line 2 I think...

Monaco:                   14:  27:  EU:   43.73:    -7.40:    -1.0:  3A:
    3A;

• Item
  • 'Monaco'
• ITU Zone
  • 14
• CQ Zone
  • 27
• Continent
  • EU
• Latitude
  • 32.73 (NORTH)
• Longitude
  • -7.40 (EAST... Negative for stupid people in N.A !!!)
• TimeZone
  • GMT -1 (Which means localtime -1 is GMT)

Next Follows the Prefix list...

Which (and why we picked this 1st) is

- 3A

Simple - And station start has a call of 3A??? comes from Monaco.

A little more complex

This is 1 'Entry' in the file for the Spratly islands (line 3 ?)

Spratly Islands:          26:  50:  AS:    9.88:  -114.23:    -8.0:  1S:
    9M0,BM9S,BN9S,BO9S,BP9S,BQ9S,BU9S,BV9S,BW9S,BX9S,=DX0NE;

This is a nearly simple file... it states

• Item
  • 'Spratly Islands'
• ITU Zone
  • 26
• CQ Zone
  • 50
• Continent
  • AS
• Latitude
  • 9.88 (NORTH)
• Longitude
  • -114.23 (EAST... Negative for stupid people in N.A !!!)
• TimeZone
  • GMT -8 (Which means localtime -8 is GMT)

Ok so that was the easy part ...

We now have a list of Prefixes ...

9M0,BM9S,BN9S,BO9S,BP9S,BQ9S,BU9S,BV9S,BW9S,BX9S,

Any Station that starts with this is in the Spratly Islands, but ... =DX0NE, is a 'special' rule, as this event station will be activating in the Spratlys very soon.

China , United States I think are the most complex, followed by the Artic stations. Just take the rules slowly... and you can build up a parsing list.

This means you now will have the ability to know exactly where a callsign is issued from - there will be the odd one, which does not match - generally these are pirate - as the maintenance of CTY.dat is top class.