+=== 9^RBN^The Reverse Beacon or Skimmer System
+Please read the document /spider/RBN.mojo. This has the latest information
+about RBN/Skimmer setup.
+
+=== 0^RBN^The Reverse Beacon or Skimmer System
+DXSpider now has the ability to show spots from the Reverse Beacon Network
+or "Skimmers", if your sysop has enabled the feed(s) (and has the bandwidth
+to both receive the feeds and also to pass them on to you.
+
+Currently there are two RBN/Skimmer feeds available which, at busy
+times can send up to 50,000 spots/hour EACH. Somewhere in the low
+1000s is more normal. Clearly this is not much use to the average user
+and so DXSpider "curates" them by removing duplicates and checking for
+invalid callsigns or prefixes, as well as using some algorithms to fix
+the rather variable frequencies that some skimmers produce
+(particularly for CW spots).
+
+This means that the format of the spot that you see is completely
+different to the spots that the RBN feeds supply and, as a result of
+the "curation" reduces the volume of spots to you by between 8 and 11
+times.
+
+See SET/SKIMMER (or SET/WANTRBN) for more information on enabling
+RBN/Skimmer spots and also on selecting particular categories (e.g CW
+or FT8/FT4) - which has the side benefit of reducing the volume of
+spots that you receive even more!
+
+Here are some examples of the output:
+
+DX de LZ4UX-#: 14015.5 ON7TQ CW 6dB Q:9 Z:5,14,15,40 14 0646Z 20
+DX de VE7CC-#: 3573.0 N8ADO FT8 -14dB Q:4 Z:4,5 4 0647Z 3
+DX de DM7EE-#: 14027.5 R1AC CW 9dB Q:9* Z:5,15,17,20 16 0643Z 14
+DX de WE9V-#: 7074.0 EA7ALL FT8 -9dB Q:2+ Z:5 14 0641Z 4
+
+Note that UNSET/DXGRID, UNSET/DXITU and SET/DXCQ are in operation in
+these examples. This is completely optional.
+
+The comment field has been completely changed in order provide as much
+information, in as smaller space, as possible. All the irrelevant
+information has been removed.
+
+You can use the Category (CW and FT8 in these examples) to with
+SET/SKIMMER (or SET/WANTRBN) to, rather coarsely, select which spots
+you require. You can refine this further by the use of Filtering. See
+SET/SKIMMER or SET/WANTRBN for more information. But the short answer
+is that these are spots and are filtered like any other spot, unless
+you want to filter these spots differently, in which case you can use
+REJECT/RBN and ACCEPT/RBN in exactly the same way as ACCEPT/SPOT and
+REJECT/SPOT. If you don't use RBN filters then these spots will be
+filter by any spot filters that you may have.
+
+The next field (6dB, -14dB etc) is the LOWEST reported signal that was
+heard.
+
+The Q: field is the number of skimmers that heard this spot (up to 9
+shown, but it could easily be many more). If Q: is > 1 (especially on
+CW) then you can be reasonably certain that the callsign is accurate,
+especially on CW. 'Q' stands for "Qualitee" :-)
+
+If there is a '*', it means that there was a disagreement about
+frequency. In fact, particularly for CW spots, I have see
+disagreements of 600Hz. Which is a worry. The frequency that is shown
+is the majority view of all the skimmers spotting this call. You may
+have to fossick about the airwaves to find the actual frequency :-)
+
+There are stations that are permanently on, like Beacons, and also
+others that have long sessions on the same frequency and do a lot of
+CQing. If they have been on for a certain length of time and they
+reappear before their cache entry expires (about 2 hours), then they
+are respotted. This is indicated by the '+'. NOTE - if they change
+frequency, this will generate new spots. Each callsign/frequency pair
+could respotted separately for as long as any individual
+callsign/frequency pair remain in the cache.
+
+The Z: field is present then that indicates the other CQ zones that
+heard this spot - not including the skimmer that is shown. I show as
+many as there are in whatever space is left in the comment
+field. Note: if you have any of the optional flags around the time
+then they may overwrite part of this field.
+
+If there is NO filter in operation, then the skimmer spot with the
+LOWEST signal strength will be shown. This implies that if any extra
+Z: zones are shown, then the signal will be higher in those zones.
+
+If you have a filter (for instance: ACCEPT/SPOT by_zone 14 and not
+zone 14 or zone 14 and not by_zone 14) where '14' is your QTH CQ
+zone. You will, instead be served with the lowest signal strength spot
+that satisfies that filter. Incidentally, this particular style of
+filter is quite useful for RBN spots, as it reduces the volume and is
+likely to be more relevant for casual use. If this filter is too broad
+(or narrow) for your normal spotting requirements, then you can use
+ACCEPT/RBN with the same filter specification and it will only apply
+to RBN spots. You can also replace '14' with a list like '14,15' if
+you want to broaden it out. You will still get the same Z: list (if
+any) whether you filter or not.
+
projects / spider.git / blobdiff