CT1BOH Spot Quality AR-Cluster V6 Telnet User Manual [Stored by DL9GTB]



This beta version of AR Cluster Version 6 is the first DX cluster node software to incorporate user-configurable RBN spot quality filtering. It provides all the features of the public Version 6 software, with the option of adding filtering using the CT1BOH algorithm to improve spot quality from the Reverse Beacon Network. These filters only work against Skimmer/RBN spots, and may be combined with other Version 6 filters with the usual Boolean operators.




Spot Quality Filter Options

SkimValid -   Filter on the V tag., which is assigned by looking back to see if there are two more spots of the same call, on the same frequency (+/- 0.3 KHz).


Examples:  Set DX Filter SkimValid (displays only spots identified as Valid

                Set DX Filter NOT SkimValid (displays only spots identified as not Valid


SkimQsy -  Filter on the Q tag, which is assigned because the call was found to have been previously verified but the new spot frequency is +/- 0.4 KHz different from that last reported.


Examples:  Set DX Filter SkimQsy (displays only spots flagged as Q)

                Set DX Filter NOT SkimQsy (displays only spots not flagged as Q)


SkimBusted – Filters on the B tag, which is assigned by looking back and determining that there is a similar spot already tagged as V, spotted on the same frequency as the new spot, +/- 0.1 KHz.   A “similar” call is one which can be transformed into the new spot by character insertion, deletion or substitution.


Examples:  Set DX Filter SkimBusted  (Displays only B spots)

                        Set DX Filter NOT SkimBusted  (Displays only spots not flagged as B)


SkimUnknown – Filter on the ? tag.  Any spot that is not given a V, B or Q tag is tagged “?” until/unless it qualifies for one of the other tags.


 Examples:         Set DX Filter SkimUnknown  (Displays only “?” spots)

                Set DX Filter NOT SkimUnknown  (Does not display any ? spots)



SkimCtyCnt – Filter on the number of Skimmers currently spotting stations in a given country or (in the case of the USA) ITU zone.  This filter is useful in determining which areas do not have adequate Skimmer coverage for effective working of the CT1BOH algorithm.


Examples:          Set DX Filter SkimCtyCnt < 3 (displays all skimmer spots from countries being spotted by fewer than 3 active Skimmers)


                Set DX Filter SkimCtyCnt > 3 (displays all skimmer spots from countries being spotted by 3 or more active Skimmers). It’s not likely you would want to limit your reception of spots this way, but the filtering capability is there for debugging and evaluation.




Compound Filters


As with all Version 6 filters, standard Boolean operators AND, NOT and OR, together with nested parentheses, can be used to construct filters to meet your specific needs.  These filter setup strings are not case-sensitive. You can also mix these RBN quality filters with non-RBN spots and other filtering types.


Examples:  Set dx filter not skimbusted and not skimqsy will filter out busted spots and images, while passing all spots as soon as they are made by a single Skimmer (before they are verified).      


                Set dx filter band=40 and  (skimvalid or skimctycnt <2) will only display 40-meter spots that have been assigned the V tag and those 40-meter spots that are spots of stations in a country heard by only one Skimmer.


                Set dx filter not skimbusted will only display spots that the system thinks are not busts.  This could be very useful for an assisted or multi-op on Sunday afternoon when most calls heard by the RBN have already been worked           





Show Skimmer – Displays a list of all Skimmers that are currently reporting, along with CT1BOH algorithm totals


        Example: SHow Skimmer


Skimmer Configuration based on CT1BOH algorithms:

 Call      FreqQSY%  TotCnt   ?Cnt  ValidCnt  QsyCnt BustCnt

G3BJ-#        0.0       9       2       7       0       0

NC7J-#        0.0       6       1       5       0       0

RZ3DVP-#      0.0       13      1       12      0       0

DK9IP-#       9.1       11      0       9       1       1

SV8RV-#       11.1      9       2       6       1       0

K1FC-#        20.0      5       1       3       1       0

F4DXW-#       33.3      3       1       1       1       0



ShowSkimCty [Band] - For a selected band, displays the countries recently spotted and the Skimmers spotting each country. 




Trying It Out



In order to use the new filters the AR-Cluster node must have connection to the RBN and the CT1BOH processing enabled.   Contact your local AR-Cluster sysop with any questions. Users can test with the RBN node at arcluster.reversebeacon.net, port 7000 or at ab5k.net.




Other DX command references:

Command summary:  Command Summary  

DX command docs:    DX