Monitoring Beacons

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PropView can assess actual propagation by monitoring beacons in the NCDXF/IARU Network, either by band, by location, or by bearing from your QTH.  This beacon network involves 18 continuously transmitting beacons deployed around the world, transmitting on the 20m, 17m, 15m, 12m, and 10m amateur bands. Each beacon has a 10 second slot on each band, during which it transmits its callsign in CW followed by 4 dashes of 1 second duration.  The callsign and first dash are sent at 100 watts; the remaining dashes are sent at 10 watts, 1 watt, and 0.1 watt respectively. With 18 beacons transmitting in turn, a cycle is completed on each band every 3 minutes. To minimize beacon hardware, transmission occurs on one band at a time, yielding a schedule with each beacon transmitting once one each band durijg a cycle. Listening to every beacon on every band with a single receiver requires five cycles -- 15 minutes.

Monitoring beacons with PropView requires that your PC's clock be accurate to the second. This can be accomplished with free software such as AboutTime or Dimension 4 that periodically synchronizes with time servers over the internet, or with PC hardware that synchronizes with time signals received from WWVH or from GPS satellites such as WinTick.

PropView's Beacon Monitor makes it easy to select the beacons you wish to monitor, and can automate required changes in your receiver's frequency and required changes in the bearing of your directional antenna. To activate the monitor, click the Monitor button in the Beacon panel at the bottom of PropView's main window. After PropView displays its Beacon Monitor window, check the Enable box in the upper left corner of this window's Monitor panel.

The Beacon Monitor window contains two panels: a Monitor panel that lets you specify the beacons to which you wish to listen, and a Beacon Schedule panel that shows you the upcoming 18 slots of the schedule PropView has assembled for you.

Within the Monitor panel are three sub-panels, corresponding to the three different ways you can select beacons for inclusion in your schedule:

The Band sub-panel lets you monitor all beacons on a specific band. Click the 20m button, for example, and two things happen:

The Beacons sub-panel provides two functions: it lets you select beacons arbitrarily, constructing the shortest possible schedule that includes all of beacons you wish to monitor, and it provides a visual indication -- using red font -- of which beacons are included in the schedule. Depending upon your selections, your schedule may involve up to five 3-minute cycles, containing a total of 90 beacon transmission events. Thus the Beacon Schedule panel may show only some of the beacons in your schedule -- those that will be transmitting within the next 180 seconds. 

If you have a directional antenna, its convenient to monitor groups of beacons whose bearing from your QTH are within your antenna's beam width. When you chose a beam heading in the Octant sub-panel, PropView creates a schedule containing all beacons whose bearing lies within 30 degrees, corresponding to a 60 degree beam width. If you've checked this panel's Rotate box and are running DXView version 1.5.1 or later with a PC-controllable antenna rotator, selecting a beam heading will automatically rotate your antenna. Since octants are 45 degrees in width and PropView assumes a 60 degree beam width, don't be surprised if some beacons appear in schedules generated from more than one octant selection.

The Band, Beacons, and Octant sub-panels each provide independent means of generating a beacon schedule, though all use red font in the Beacons sub-panel to indicate selected beacons. Whenever you create a schedule using one of these sub-panels, it immediately replaces the previously active schedule. As long as the Enable checkbox in the Monitor panel's upper left corner is checked, PropView will advance the Beacon Schedule every 10 seconds; the top-most entry in this schedule identifies the currently transmitting beacon, its location, its frequency, its bearing from your QTH, and its distance from your QTH in either miles or kilometers, as specified in the configuration window. If you are running DXView version 1.5.1 or later, you can check the Map box in the Monitor panel; doing so will direct DXView to display the location of the currently-transmitting beacon on its world map. Checking the Predict box in the Monitor panel directs PropView to compute and display a propagation forecast for the currently transmitting beacon so you can compare actual and predicted propagation.

If you are running Commander version 3.7.3 or later with the Monitor panel's Enable box checked in PropView's Beacon Monitor window, then checking the QSY box in the Monitor panel will direct Commander to 

PropView only changes your radio's frequency as required by the beacon schedule. If all events in the schedule occur on 21150 kHz, PropView will set your radio's frequency once, so if you manually change frequency or mode in this situation, its up to you to appropriately restore the radio's settings. If successive transmissions in the schedule occur on different frequencies, PropView will QSY your radio for each transmission.

The Monitor panel's Transceiver sub-panel lets you specify a positive or negative Offset in Hertz; you can use this to position beacon signals within your transceiver's receive passband. 

By design, all beacons can be monitored on a single band within one 3-minute cycle. Click the Band sub-panel's 15m button, for example; note that the Band sub-panel's caption parenthetically indicates the schedule length in cycles. If you check a box in the Beacon sub-panel, a one-cycle schedule will be created. If you check another box, whether the schedule must be expanded to two cycles depends on which two beacons you have chosen. As you select additional beacons, the schedule is automatically extended to accommodate them. If you select every beacon, a 5-cycle schedule will be generated.

Not all beacons are active, or are active on all bands. If you click the 20m button, for example, inactive beacons will remain in black font in the Beacons panel. These stations are currently inoperative; you can check their boxes in the Beacons panel, but no schedule entries will be generated. PropView obtains information about Beacon location and Beacon schedules from a pair of text files named BeaconLocation.txt and BeaconSchedule.txt , located in PropView's folder. The BeaconLocation.txt file specifies one line for each beacon with the following information in comma-delimited format:

The BeaconSchedule.txt file specifies one line for each active beacon transmission with the following information in comma-delimited format:

A beacon that is currently inactive on all bands would have no entries in BeaconSchedule.txt. A beacon that is active on some but not all bands would only have entries in BeaconSchedule.txt for the active bands. 

If the location of one or more beacons changes, as reported by the NCDXF

  1. terminate PropView

  2. update the BeaconLocation.txt file accordingly

  3. start PropView

If the status of one or more beacons changes, as reported by the NCDXF

  1. update the BeaconSchedule.txt file accordingly

  2. in the Monitor panel, uncheck the Enable box

  3. in the Monitor panel, check the Enable box

Distance and bearing to each beacon is computed using the QTH latitude and longitude specified in the Transmitter Panel on the Parameters tab of PropView's main window; you can more conveniently set QTH information using DXView. Changing your QTH location is immediately reflected in the distance and bearings shown in the Beacon Schedule.

 

 

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