User DX Spots  AR-Cluster User Manual

DX spots share important information about amateur radio stations such as their callsign, operating frequency, date, time and an optional comment.  This information is valuable for amateurs chasing rare countries or operating in contests.  DX Spots are shared across the various DX clusters and any user connected to the clusters.  By being connected into a DX Cluster you will get DX spots in real-time as they are spotted.  You can also query the database for past DX spots.   Note if you have user filters activated, they will also be applied to both the real-time spots and spot queries of the database.


Additionally, you can add DX spots into the network.  Remember, the cluster network depends on spots, so please spot.


Please use DX spots to spot information relating to real propagation reports of operating stations.  Questions and comments are usually passed using the Announce function.  If you do have to use a DX spot to pass a comment, make sure its listed on a frequency on the very bottom of the band.

Real-Time DX Spots

As soon as you connect into a DX Cluster you will automatically start receiving DX spots.  These spots can be furthered filtered based on individual user preferences.  The Filter section of this manual described the various filtering options available. 


If there is room in the comment field, ARC nodes also show the country abbreviation (CTY), for the spot. The CTY display is optional and controlled by the following commands:





ARC nodes also show the country(CTY) or state of the spotter at the end of the spot.   The display of the spotter’s state or country at the end of the DX spot may cause parsing issues with certain logging and contest programs.  It can be turned on and off with the following commands.





The display of real-time DX spots can be controlled with the following commands.





Normal DX Spots Queries

You may also wish to check on spots posted in the past.  The general command to do this is SHOW/DX.  Without any other arguments, this command will output the last few spots posted.  




If you want to see more spots than this you can also add an optional number to the end of the command as in SHOW/DX/nn.    This will allow you to look at the last 20 or 30 spots.





You can filter the displayed spots by band by adding a band in either wavelength or frequency.


show/dx 14           OR      show/dx 20
show/dx/20 21    OR      show/dx/10 15
show/dx/20 28    OR      show/dx/20 10

It is also possible to check for certain spotted callsigns.


show/dx v73aq
show/dx/10 k5k


It is also possible to check for spots in a particular country.  The “*” character at the end of the command tells ARC to display all spots from the country extracted from the callsign.  To show all spots from the Marshall Islands:


show/dx v73*
show/dx/20 V73AQ*


You can also check for DX spots across a specified frequency range.


show/dx 21000-21050
show/dx 80           (3490 <> 3600)
show/dx 75           (3600 <> 4010)
show/dx 3             (3490 <> 4010)

You can also check for DX spots by a specific band and callsign.


show/dx 12 vk0hi 

You can also check for DX spots by a specific band and country. 


show/dx 12 vk*

If you logged off the cluster for a few minutes and then got back on, the SHOW/DX MISSED command can be used to display a list of spots since your last logout. 


show/dx missed

The SHOW/ZONE command can be used to display a list of spots in a particular CQ Zone. 


show/zone 18

The SHOW/ITU command can be used to display a list of spots in a particular ITU Zone. 


show/itu 32

The SHOW/DX STATS command will display a list of the DX spot totals for selected intervals from the last hour to the last month.


            show/dx stats


The SHOW/VLF command can be used to display a list of VLF spots. 



The SHOW/IOTA command can be used to display a list of IOTA spots. 




The SHOW/4MTR command can be used to display a list of 4 meter spots. 




Formatted DX Spots Queries

The DX spot format varies based on the spot being a real-time spot or a queried spot with e SH/DX command.  This feature is by design and allows you to tell the new real-time spots from older spots you just queried.


The SH/FDX (Formatted DX) command can be user to replace the SH/DX command and the output will be in the real-time format.  This is useful if you want to input queried spots into a contest program that only processes spots in the real-time format.



show/fdx/30 v73aq


The SH/FZONE and SH/FITU  can be used to display CQ zone and ITU zone spots in the real-time format.


show/fzone 18
show/fitu 32


Advanced DX Spots Queries

AR-Cluster also allows the user to program his own DX spot queries using SQL.  SQL queries are very powerful and allow you to build custom commands to query the DX spot database.   With some simple examples, is not too hard to pick up some SQL basics.  The SH/DX query commands can be ran against any of the fields in the DX spot database.   Note, DTS is date-time–stamp.


sh/dx/10 where dx = 'XZ0A'

sh/dx/50 where freq > 50000.0 and freq < 54000.0

sh/dx/50 where cty = 'V7'

sh/dx/50 where spotter = 'N5CQ'

sh/dx/50 where FromNode = 'WU3V'

sh/dx/50 where CqZone = '23'

sh/dx/50 where ItuZone = '64'

sh/dx/50 where Bnd = '12'

sh/dx/50 where Mode = 'CW'

sh/dx/50 where SpotterCty = 'VE'

sh/dx/25 where SpotterSubCty = 'TX'

sh/dx/30 where Comment = 'RTTY'

sh/dx/50 where DTS > #2/1/00# AND DTS < #5/1/00#

sh/dx/50 where DTS > #2/1/02 11:00am# AND DTS < #2/1/02 12:00pm#


You can also use the LIKE operator and the wildcard character "%" to do partial matches.  To show spots with the word "QSL" anywhere in the comment field use the following example.


sh/dx/50 where comment LIKE '%QSL%'


You can use the SQL ORDER BY operator to order the spots by date and time.  Normally you would not specify an ORDER BY operator since, you want to see the most recent spots shown first.  If you want to see older spots, you can use the ORDER BY ASC operator.


sh/dx/30 where DX = 'XZ0A' ORDER BY DTS ASC


Compound SQL queries can be generated by combining two or more operations into one query.


sh/dx/50 where Mode = 'CW' AND Bnd = '10' AND spotter = 'N5CQ'

sh/dx/50 where dx = 'FO0AAA' AND DTS > #2/1/00# AND DTS < #5/1/00#

sh/dx/50 where dx = 'FO0AAA' AND comment LIKE '%QSL%'


The database fields that are available for Advanced DX Spot Queries are:



Callsign of the spotted DX


Country of the spotted DX – follows ARRL.CTY file


Frequency of the spotted DX – Example 14195.0


Comment in the spotted DX


Callsign of the spotter


Callsign of the spotting node




CQ zone for the spot


ITU zone for the spot


AR-Cluster tag indicating the spot source for spot suckers, UserSpot = 0,  PC26Spot = 1, OH2AQSpot = 2, and MIRCSpot = 3


Band for the spot – Example 20


Mode for the spot – Example SSB


Country of the spotter – follows ARRL.CTY file


State of the spotter – from the AR-Technology callsign database


Node/Station that we received the spot from


Spotting DX

To post a DX spot, use the DX command. The syntax options are shown below.


dx frequency callsign (optional comment)
dx callsign  frequency  (optional comment)

The frequency parameter can be in megahertz or kilohertz and is the frequency that the station is operating on.  The callsign is the callsign of the station you have worked or heard. The maximum length of characters in a callsign is twelve.  The optional comment can be user to tell the stations name, location or QSL information.  Don’t worry if you forget whether the frequency or callsign comes first, ARC will sort that out for you.


dx 14088.8 ja1bn
dx ja1bn 14088.8

Once posted, the DX spot will be send to all stations in the network.  It will also be echoed back to you as a confirmation.  


If you need to do a test spot from your contest software, spot the station TE1ST.  That is a reserved call that will not be sent throughout the network.  It will be echoed back to you for confirmation.