Cleaned Logs
Cleaned logs for the years 2018 to 2025 may be downloaded from this
directory.
The cleaned logs are combined into a single file; but data for
individual stations and years may be extracted trivially from the
combined file.
The cleaned logs are the result of processing the
QSO:
lines from the entrants' submitted Cabrillo files (as [gratuitously] modified by the ARRL) to ensure that all
fields contain valid values and all the data match the
column-specific standard format for this contest.
Any line containing illegal data in a field has simply been removed. Also, only the
QSO:
lines are retained, so that each line in the file can be processed
easily. All QTH multipliers are rendered as two letters, and the power
is rendered as four digits, regardless of how the submitted log recorded
these two fields; this should simplify processing the logs by scripts
or programs, as should the use of fixed-length records in these cleaned
files.
Augmented Logs
Links to augmented logs for the same years may likewise be downloaded from the same
directory. The augmented logs are combined into a single file; but data for
individual stations and years may be extracted trivially from the combined
file.
The augmented logs
for the ARRL DX contests contain the same information as the cleaned logs, but with the addition of
some useful (derived) information on each line. The information added to each line comprises:
- The sequence of four characters that are the same for each entry in a particular log:
- a. letter "A" or "U" indicating "assisted" or "unassisted"
- b. letter "Q", "L", "H" or "U", indicating respectively QRP, low power, high power or unknown power level
- c.
letter "S", "M", "C" or "U", indicating respectively a single-operator,
multi-operator, checklog or unknown operator category
- d. character "1", "2", "+" or "U", indicating respectively that the number of transmitters is one, two, unlimited or unknown
- A four-digit number representing the time if the contact in minutes
measured from the start of the contest. (I realise that this can be calculated
from the other information on the line, but it saves subsequent processors of the file considerable time to have the
number readily available in the file without having to calculate it each time.)
- Band
- A set of fourteen flags, each -- apart from column k and column n -- encoded as T/F:
- a. QSO is confirmed by a log from the second party
- b. QSO is a reverse bust (i.e., the second party appears to have bust the
call of the first party)
- c. QSO is an ordinary bust (i.e., the first party appears to have bust the
call of the second party)
- d. the call of the second party is unique
- e. QSO appears to be a NIL
- f. QSO is with a station that did not send in a log, but who did make 20
or more QSOs in the contest
- g. QSO appears to be a country mult (may be T for W/VE stations only)
- h. QSO appears to be a state/province mult (may be T for DX stations only)
- i. QSO is an exchange bust (i.e., the received exchange appears to be a bust)
- j. QSO is a reverse exchange bust (i.e. the second party appears to have bust the exchange of the first party)
- k. This entry has three possible values rather than just T/F:
- T: QSO appears to be made during a run by the first party
- F: QSO appears not to be made during a run by the first party
- U: the run status is unknown because insufficient frequency information is available in the first party's log
- l. QSO is a dupe
- m. QSO is a dupe in the second party's log
- n. RBN information (see below)
- If the QSO is a reverse bust, the call logged by the second party; otherwise, the placeholder "-"
- If the QSO is an ordinary bust, the correct call that should have been logged by the first party; otherwise, the placeholder "-"
- If the QSO is a reverse exchange bust, the exchange logged by the second party; otherwise, the placeholder "-"
- If the QSO is an ordinary exchange bust, the correct exchange that should
have been logged by the first party; otherwise, the placeholder "-"
RBN Information
In CW contests from 2009 onwards, the
RBN
has been active, automatically
spotting the frequency at which any station calling CQ was transmitting.
To reflect possible use of RBN information, the augmented files include
a fourteenth column. For the sake of uniformity, this column is
present in all the augmented files, regardless of whether the RBN
actually contributed useful information to a particular contest.
Each QSO has one of several characters in the fourteenth column of flags. These characters should be interpreted as follows:
'-'
No useful RBN-derived information is available for this QSO.
'0'
The worked station (
i.e., the second call on the log line) appears to have begun to CQ on this frequency within (roughly) 60 seconds prior to the QSO.
'A' to 'Z'
For the
nth letter of the alphabet: the worked station appears to have been CQing on this frequency for (roughly)
n minutes prior to the QSO.
'+'
The worked station appears to have been CQing for more than 26 minutes on this frequency.
'<'
Because the the RBN is distributed, and because each contest entrant
station has its own clock, there is generally a skew between the reading
of the clock of the station making the QSO and the timestamp from the
RBN at which it believes a posting was made (indeed, it's unclear from
the RBN's [lack of] documentation exactly how the timestamp on an
individual RBN posting is to be interpreted). If the character '<'
appears in the the RBN column, it indicates that the raw values of the
clocks suggest that the QSO took place up to two minutes
before
the RBN reported the worked station commencing to CQ at this frequency.
When this occurs, the most likely interpretation is that there is
non-negligible skew between the two clocks, and the station was actually
worked almost as soon as a CQ was posted by the RBN. But it might also
mean that the entrant was simply lucky and found the CQing station just
as it fired up on a new frequency.
Notes:
- The encoding of some of the flags requires subjective
decisions to be made as to whether the flag should be true or false;
consequently, and because the ARRL has yet to understand the importance
of
making the scoring code public, the value of a flag for a specific QSO
line in some circumstances might not match the value that the ARRL has
assigned. (Also, the ARRL has additional, non-public, data available.)
- I made no attempt to deduce or infer the run status of a QSO in
the second party's log (if such exists), regardless of the status in the
first party's log. This allows one cleanly to perform correct
statistical analyses anent the number of QSOs made by running stations
merely by excluding QSOs marked with a U in column k.
- No attempt is made to detect the case in which both participants of a
QSO bust the other station's call. This is a problematic situation
because of the relatively high probability of a false positive unless
both stations log the frequency as opposed to the band. (Also, on bands
on which split-frequency QSOs are common, the absence of both transmit
and receive frequency is a problem.) Because of the likelihood of false
positives, it seems better, given the presumed rarity of double-bust
QSOs, that no attempt be made to mark them.
- The entries for the exchanges in the case of exchange or reverse
exchange busts are normalised to two-letter or four-digit values in the same manner as
described above for the exchanges in the cleaned logs.
