Filtering the Spot Database Display

Through the use of filters, you can direct SpotCollector to limit the display of Spot Database Entries to those that match specific criteria, such as "only Spot Database Entries for stations

When you specify a filter, the Spot Database Display immediately hides all Spot Database entries that don't conform. Spot Database Entries created after you specify a filter are added to the Spot Database, but only appear in the Spot Database Display if they conform to the current filter. If you modify or clear the current filter, the Spot Database Display is immediately updated to show only conforming entries.

Why Filter the Spot Database Display?

There are three basic reasons to filter entries in SpotCollector's Spot Database Display:

  1. to analyze and understand the behavior of DX stations with whom a confirmed QSO would advance your award progress, so as to increase your chances finding them QRV
  2. to identify propagation openings that can be exploited to work DX stations with whom a confirmed QSO would advance your award progress
  3. to eliminate the clutter of active DX stations with whom a confirmed QSO would not advance your award progress, or with whom a confirmed QSO would advance your award progress but are unlikely to be workable given current propagation

Filtering the Spot Database Display by "region of spotting station" speaks to the second half of #3: "only show active DX stations spotted by stations in my region, or in regions near mine". This approach assumes that you won't be able to work a needed DX station unless its spotted by someone near you. While often valid on bands like 6m or 2m, this assumption is often invalid on HF bands. The first workable spot of a needed DX station frequently comes from a station well outside your region. If a station in Japan is the first to spot P5DX on 14010 and you have propagation to North Korea, why remain ignorant of that spot until a station in your region spots P5DX? By then, the pileup could be impenetrable.

When DXLab first became publicly available back in 2001, HF propagation prediction was largely accomplished with the IONCAP engine, which being written in Fortran expected input structured as 80-column Hollerith card images, and generated tables of numeric data as output. To make HF propagation forecasting more accessible to DXLab users, PropView was developed to provide a graphical front end for IONCAP, enabling the user to select a DXCC entity or click on a location in DXView's world map, and then generate a graphical propagation forecast showing openings to the user's station by band and time-of-day. Back then, it took tens of seconds to generate a propagation forecast, good enough to decide when and where to stake out needed DX stations.

Since 2001, the IONCAP engine has been superceded by the VOACAP engine, and CPU performance has increased dramatically. As a result, it's now possible to configure SpotCollector to direct PropView to generate a propagation forecast for every needed DX station in the Spot Database Display. The results of these predictions are placed in each Spot Database Display Entry, so you can filter the Spot Database Display based on the probability of their being an opening between your station and each Entry's callsign. Like weather forecasting, HF propagation forecasting is not 100% accurate, but filtering with "probability of a shortpath opening is greater than 50%" is a generally more effective than filtering based on the locations of spotting stations.

You can also analyze the information in your Spot Database Display in a way that reveals propagation openings.

Specifying a Spot Database Filter

The Spot Database window's Filter panel provides the means by which you specify the current filter. The Filter panel's caption displays the current filter within square brackets, for example

Filter: [call=P5DX]

which means that the Spot Database Display only shows entries whose callsign is VK9NS and that have not been individually hidden . If the current filter is empty, then the Filter Panel's caption will be

Filter: All

which means that the Spot Database Display shows every Spot Database Entry.

The Spot Database window's filter panel provides three groups of filters: General, Context, and SQL.

General Filters: filtering by Callsign, DXCC entity, Frequency, and Need

The four General filters let you choose one of four criteria; some of these criteria reference the contents of the (unlabeled) General Expression textbox, located on the left side of the Filter panel.

  1. Need: displays only Spot Database Entries for DX stations needed to satisfy your DXing objectives (the General Expression textbox contents are ignored)

  2. Call: displays only Spot Database Entries for DX stations whose callsign is specified in the General Expression textbox

  3. DXCC: displays only Spot Database Entries for DX stations whose DXCC prefix is specified in the General Expression textbox

  4. Freq: displays only Spot Database Entries for DX stations spotted on frequencies near the current transceiver frequency as reported by Commander (the General Expression textbox contents are ignored)

You can use * (asterisk) as a wildcard character when specifying either callsigns or DXCC prefixes in the General Expression textbox. For example,

will match KH6/K6MIO, K6MIO, and K6MIO/KH6.

With Commander running, selecing the Frequency filter and sorting the Spot Database by frequency will automatically shows spots near your transceiver frequency as you QSY. You can enable the Mode and/or Origin filters for additional specificity.

To clear the General filters, click the button labeled X to the immediate right of the General Expression textbox. When the General filter is cleared, the Spot Database Display shows all Spot Database Entries that conform to the four Context filters: Band, Mode, Continent, and Origin filters.

Filtering by Band

The Band filter enables you to display only Spot Database Entries for DX stations spotted on frequencies within specified bands; clicking the Filter panel's Band button displays the Band Filter window, with checkboxes for each amateur band from 160m to 12cm. The Spot Database Display will not show Spot Database entries with frequencies in bands having Band Filter boxes not checked. If Commander is running, checking the Transceiver Band Only box will automatically keep the Band filter set to only show spots for your transceiver's current band; this feature is currently limited to 160m through 2m. SpotCollector retains a history of the most recent 16 Band filter configurations; you can navigate within this history using the Band filter's forward and back arrow buttons to select recent or previous configurations respectively. The Band filter can also be configured to

Filtering by Mode

The Mode filter enables you to display only unhidden Spot Database Entries for DX stations spotted in specified modes; clicking the Filter panel's Mode button displays the Mode Filter window, with checkboxes for many amateur modes. The Spot Database Display will not show Spot Database Entries with modes having Mode Filter boxes not checked.

Filtering by Continent

The Continent filter enables you to display only unhidden Spot database entries for DX stations located in specified continents; clicking the Filter panel's Cont button displays the Continent Filter window, with checkboxes for each of the six continents. The Spot Database Display will not show Spot Database entries with continents having Continent Filter boxes unchecked. Unchecking the Continent filter's ? (unknown) checkbox is an effective way to suppress the display of Spot Database Entries whose callsigns do not map to a DXCC entity; such callsigns are generally bogus.

Filtering by Origin

The Origin filter enables you to display only Spot Database Entries for DX stations that have been spotted from specified geographic locations; clicking the Filter panel's Origin button displays the Origin Filter window, with checkboxes for major geographic locations:

The Spot Database Display will hide Spot Database entries whose DX stations have not been spotted from any geographic location with Origin Filter boxes checked. If the Origin filter panel's NA-M box is checked, for example, then only Spot Database Entries for DX stations that have been spotted by a station in the North American mid-west will be visible in the Spot Database Display. Suppose a DX station is initially spotted from Europe; its Spot Database Entry will be hidden. If this DX station is then spotted from the North-American mid-west, its Spot Database Entry will become visible. If this DX station is then spotted from Japan, or is again spotted from Europe, its Spot Database Entry will remain visible -- even though the most recent spotting station in the Entry will be a Japanese or European callsign.

To make the Origin filter possible, SpotCollector maintains eight fields for each Spot Database Entry:

Thus unchecking all of the Origin filter's boxes except its NA-M box means "Hide all Spot Database Entries whose NAM field does not contain Y"

To display a chronologically-ordered list of all stations that have spotted a Spot Database Entry's DX station, right-click the Entry and select the Display spots of menu command.

Filtering by Propagation Probability

You can configure SpotCollector to direct PropView to generate a propagation forecast for every needed DX station in the Spot Database Display. The results of these predictions are placed in each Spot Database Display Entry, so you can filter the Spot Database Display based on the probability of their being an opening between your station and each Entry's callsign.

Filtering by Age

You can specify a Maximum age (in minutes) on the Filters panel on the Configuration window's Spot Database tab. Checking the Filter panel's Age box will filter the Spot Database Display to those entries whose Last Time is no older than the specified maximum age.

Filtering by LotW Participation

If the LotW callsign database LotW.mdb is present in SpotCollector's or DXView's Database folder when SpotCollector is started, checking the Filter panel's LotW box will filter the Spot Database Display to those stations whose callsigns are known to participate in the ARRL's Logbook of the World. You can set the criteria for "known to participate" via the Maximum age of last LotW upload (months) setting in the Controls panel on the Configuration window's Spot Database tab

Filtering by eQSL Authenticity Guaranteed (AG) Membership

eQSL.cc callsign database eQSL.mdb is present in SpotCollector's or DXView's Database folder when SpotCollector is started, checking the Filter panel'seQSL box will filter the Spot Database Display to those stations whose callsigns are Authenticity Guaranteed (AG) members of eQSL.cc

Filtering by Marathon Need

With the Mrthn box checked, Spot Database Entries for stations with whom a QSO would advance your CQ DX Marathon progress are colored as "needed". Early in the year, however, the profusion of Spot Database Entries needed for Marathon can make it difficult to identify Entries for stations needed for other awards, like DXCC or WAZ. Unchecking the Mrthn box will configure SpotCollector to not color Spot Database Entries needed for Marathon as "needed" unless they are also needed for another award you are pursuing, like DXCC or WAZ. Be sure to check the Mrthn box after you complete your observation.

Filter panel caption

To avoid long, complex expressions in the Filter panel caption's display of the current filter, the following convention is used:

Thus if the Filter panel caption is

Filter: Band and Mode and [call=VK9NS]

then the Spot Database Display is showing every Spot Database Entry whose callsign is VK9NS with specific filtering by Band and Mode, but with no filtering by Continent or Origin. To see exactly which Bands and Modes are being filtered, you can click the Filter panel's Band and Mode buttons.

Hiding Spot Database Entries: individually, or automatically by keyword

You can hide an individual Spot Database Entry by right-clicking it, and choosing the Hide option in the resulting pop-up menu; the display of hidden Spot Database Entries is suppressed indendently of the above-described filtering. This mechanism can be used to dispense with the bogus spots - Pirate, SLIM, Bozo - that may occasionally appear.

To un-hide one or more hidden Spot Database Entries

  1. click the Filter panel's AutoHide button to display SpotCollector's AutoHide Filter window

  2. check the Display only hidden Spot Database Entries box

The Spot Database Display will now show only hidden entries that match the General and Context filters. You can un-hide an individual entry by

  1. right-clicking it
  2. choosing the Un-hide option in the resulting pop-up menu

Alternatively, you can click the AutoHide Filter window's Un-hide button to un-hide all entries shown in the Spot Database Display.

You can configure SpotCollector to automatically hide the Spot Database Entry for any spot whose notes contain one of 16 words you specify. To enable this functionality,

  1. click the Filter panel's AutoHide button to display SpotCollector's AutoHide Filter window

  2. in the AutoHide Filter window's word list, type in the words that will trigger automatic hiding

  3. check the AutoHide Filter window's Enable Automatic Hiding... box


Post a question or suggestion on the DXLab Discussion Group

Specifying Start and End Times for Each Band

Specifying a Maximum Distance to Spotting Station for Each Band

Filtering the Spot Database Display based on Predicted Signal-to-Noise Ratios or Opening Probabilities

Getting Started with Spot Collection

Getting Started with DXLab

SpotDatabaseFilter (last edited 2019-04-20 05:13:36 by AA6YQ)