Managing the DXCC Database

Online Help Index

DXCC Database Structure

DXView's DXCC Database contains Entries that associate callsigns with DXCC Entities and Locations within those Entities. A Location is a geographic region within an Entity that can be determined from a callsign. The callsign RA4FM, for example, is associated with the Penza region of the DXCC Entity European Russia. The governments of some DXCC Entities don't allocate callsigns in a way that allows a region to be unambiguously determined from a callsign; for such Entities, a single Location is defined with a name identical to that of the Entity. The current version of the DXCC Database is available here.

Each DXCC Entity has the following properties:

Property Content
Entity Name the Entity's full name, as defined in http://www.arrl.org/files/file/DXCC/2016_Current_Deleted.txt
Country Code the Entity's Country Code, a unique, immutable number assigned by the ARRL DXCC desk; see  http://www.dxlabsuite.com/dxkeeper/CountryCodes.htm
Entity Prefix the prefix used to represent this entity within DXKeeper, e.g. K for the United States, G for the United Kingdom
Callbook Prefix the prefix used by Pathfinder to select a country-specific callbook when seeking a QSL route for a callsign associated with this Entity
Map Prefix the prefix used to select a country map to be displayed when the user clicks the Country Map button on DXView's Info window (if the Map Prefix is foo, then DXView displays the contents of the file foo.gif its Maps folder, if this file exists)
Start Date the first date on which contacts with this Entity are deemed valid by the ARRL DXCC desk; if no date is specified, the Entity has been valid since the beginning of the ARRL DXCC program
End Date the last date on which contacts with this Entity are deemed valid by the ARRL DXCC desk; if no date is specified, all contacts after the Start Date are valid.

 

Areas within a DXCC Entity that can be determine from a callsign's prefix, e.g. a region or administrative subdivision, have the following properties:

Property Content
Location The name of the area, e.g. the Pskov, or Sicily

Note that a DXCC entity must specify a Location that is different than the Locations specified by every other DXCC entity.

Prefix List a comma-separated list of prefixes from this Location to be mapped to this Entity Name and Country Code
  • the character ~ preceding a prefix means that the prefix is for documentation purposes only and should not be associated with the Entry's DXCC Entity; this is used as a way of recording the prefixes once associated with deleted DXCC Entities.

  • a prefix may contain one of the following wildcard characters or range specifiers in order to generate multiple prefix-to-Entity associations:

    • # - expands to the numbers 0 through 9, generating 10 prefix-to-Entity associations

    • ? - expands to the letters A through Z, generating 26 prefix-to-Entity associations

    • $ - expands to the letters A through G, I through K, and M through Z, generating 24 prefix-to-Entity associations (used in defining US prefixes for the 0, 6, 7, 8, and 9 call areas)

    • % - expands to the letters A through G, I through K, M through N, and Q through Z, generating 23 prefix-to-Entity associations (used in defining US prefixes for the 1, 2, 3, 4, and 5 call areas)

    • & - expands to the letters A through G and I though K, generating 10 prefix-to-Entity associations (used in defining US AA prefixes)

    • ! - expands to the letters A through I, generating 9 prefix-to-Entity associations (used in defining the U prefixes assigned to European Russia)

    • [a-b] - expands to the letters in the range a through b; for example, [B-E] expands to the letters B, D, and E

      • a ! character following the initial [ inverts the generated letters; for example, [!B-X] generates the letters A, Y, and Z

      • multiple range specifiers can be separated by semicolons; for example, [B-E;G-J;T-W] expands to the letters B, D, E, G, H, I, J, T, U, V, and W

  • DXView's callsign-to-Entity association algorithm operates by finding the longest defined prefix that matches the callsign. Thus the callsign 3C0DX is associated with Annobon Island because it matches the 3C0 prefix defined for Annobon, pre-empting the shorter 3C prefix defined for Equatorial Guinea.  The callsign 3C1DX, however, would be associated with Equatorial Guinea since it doesn't match Annobon's 3C0 prefix. One can if necessary specify a full callsign as a prefix; the prefix DP1POL, for example, is associated with the Neumayer research base in Antarctica.

Note that the same prefix cannot be associated with more than one Entity; the reTable operation will report and ignore such attempts.

Time Zone UTC offset for this Location, in hours (positive for west of Greenwich England, negative for east of Greenwich England)
CQ Zone CQ Zone for this Location, per http://www.cq-amateur-radio.com/wazrules.html
ITU Zone ITU zone for this Location, per http://www4.plala.or.jp/nomrax/ITU/
IOTA IOTA tag for this Location, per http://www.rsgbiota.org/shortlist.php4
Continent Continent for this location - one of AF,AS, EU, NA, OC, SA 
Latitude Latitude of this Location (degrees, positive for north latitude, negative for south latitude)
Longitude Longitude of this Location (degrees, positive for east longitude, negative for west longitude)

 

An Entry in the DXCC Database comprises

A DXCC Database's Master table contains a set of Entries that cover all DXCC Entities -- current, and deleted. Prior to 2004, DXCC databases were not assigned versions. All DXCC databases released after 1-Jan-2004 contain a version designator, which is displayed in the caption of the Info window's DXCC panel, and in the Config window's Database Versions panel. If you are using a DXCC databases released prior to 1-Jan-2004, the displayed version number will be 1.?.?.

A DXCC Database contains three tables -- DXCC, Location, and Prefix -- whose entries are derived from the Master table when you initiate the reTable operation; this arrangement is purely a performance optimization. A table named Settings is used to retain information specific to a DXCC Database: its version number, and a flag indicating whether or not the Master Table has been modified without changing the version number.

Viewing and Changing  Entries in the DXCC Database

To view the DXCC Database's Master Table, click the Info window's DXCC button; when DXView displays its DXCC Database window, select the Master Table tab. The lower half of this tab contains the DXCC Database Display -- a scrollable grid  with which you can select any DXCC Database Entry; you can adjust the widths of this grid's columns by left-dragging the lines separating the column captions. The upper half of this tab contains textboxes that are populated with data from the currently-selected DXCC Database Entry. These textboxes correspond to the components of a DXCC Database Entry described above. When you select a DXCC Database Entry by clicking on it in the Database Display, these textboxes display that Entry's components. 

You can modify a component by editing its textbox; when you do so, the Save button becomes enabled, reminding you that the Entry has been modified. When you have completed all changes to an Entry, click the Save button to record them, or click the Undo button to back them out. When all additions, modifications, and deletions are complete, update the Database Version panel and then click the reTable button as described below.

To delete a record from the DXCC Database's Master table, select its entry in the DXCC Database Display, and click the Delete button. When all additions, modifications, and deletions are complete, update the Database Version panel and then click the reTable button as described below.

To add a record to the DXCC Database's Master table, scroll the grid control to the last DXCC Database Entry, which is designated by an asterisk in its first column. Click in first cell of this Entry to select it; click a second time, and DXView creates an empty Entry that you can populate via the textboxes in the tab's upper section. Click the Save button when all of the Entry's components have been specified. When all additions, modifications, and deletions are complete, update the Database Version panel and then click the reTable button as described below.

When you've completed all necessary changes, decide whether the new DXCC Database should be considered a new version, or just a modification of the existing version. If the former, enter the new version number in the Database Version panel's New textbox, and uncheck the Flag new as modified box. If the latter, leave the New textbox showing the current version, and check the Flag new as modified box. When using a DXCC Database created with Flag new as modified checked, DXView appends a plus (+) to the version number. If you are distributing the DXCC database to other users, then check the Flag new as modifying entities box to flag the DXCC database as adding, deleting or modifying one or more DXCC entities; when DXView upgrades to a DXCC database so flagged, it prompts the user to direct DXKeeper and SpotCollector to Recompute when upgrade operation is complete.

Keyboard shortcuts for the above functions are available.

As described above, the DXCC Database contains four tables. The contents of three of these tables -- DXCC, Location, and Prefix -- are computed from the Master table. Thus after adding, deleting, or modifying one or more Entries to the DXCC Database's Master table, you must regenerate these three tables; this is accomplished by clicking the reTable button. If you fail to regenerate these tables, none of the changes you made to the Master table will be available to the applications that rely on it until you perform a reTable operation. The reTable operation requires exclusive access to the DXCC Database. If SpotCollector and/or DXKeeper are running when you initiate a reTable operation, you will be notified that the operation cannot be completed; simply terminate SpotCollector and/or DXKeeper, and then click the reTable button again. Opening the DXCC Database with an application like Microsoft Access or Microsoft Excel will also prevent the reTable operation from completing.

The DXCC, Location, and Prefix tables are not made visible by DXView, though you can view them by opening the DXCC Database with Microsoft Access or Microsoft Excel. DXView does display the number of Entries in each of the DXCC Databases five tables on its Database window's Statistics tab.