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23 July 2017:

By Jari Perkiömäki, OH6BG/OG6G

Do-It-Yourself VOACAP HF Propagation Predictions for DXpeditions

I am happy to announce that VOACAP Online has now an option to offer do-it-yourself HF propagation predictions, suitable for the websites of DXpeditions (and for other needs, too).

If you wish to embed the propagation prediction component in your pages, just use the following code:

<iframe width="100%" height="115px" frameborder="0" src="http://www.voacap.com/charts/?c=CALLSIGN&l=TXLOCATOR&y=YEAR&m=MONTH-NUMBER&p=TXPOWER&me=MODE"></iframe>

where:

ParameterVALUEDescription
cCALLSIGNThe callsign of the DXpedition (the Transmitter site) the prediction is made for, e.g. &c=3Y0Z.
l (like Lima)TXLOCATORThe Maidenhead Grid Locator for the Transmitter site, e.g. &l=JD15qn . To find your grid locator, please see: www.voacap.com/qth.html
yYEARThe year the DXpedition is taking place, e.g. &y=2017
mMONTH-NUMBERThe number of month when the DXpedition is taking place, e.g. for July, &m=7 .
pTXPOWERThe transmitting power in kiloWatts, e.g. 1.5 kW: &p=1.5
meMODEThe value can be either CW or SSB. If you will use both, set this parameter to CW, e.g. &me=CW

So, when all the components are in place, the complete code might look like this (the example below is for the Bouvet DXpedition in February 2018):

<iframe width="100%" height="115px" frameborder="0" src="http://www.voacap.com/charts/?c=3Y0Z&l=JD15qn&y=2018&m=2&p=1.5&me=CW"></iframe>

The layout of the prediction component on your page will be something like the one below. To see a real-life example, enter your grid locator in the field below, and press "Run"... :

The graphical predictions to be produced by the system will be similar to this:

In the result chart above, an overview of the prediction in terms of Reliability (REL), Signal Strength (S DBW, displayed as S-Meter readings) and MUFday, followed by band-specific predictions, from 80 Meters to 10 Meters, Short-Path (SP) and Long-Path (LP). The charts are all interactive as you hover the mouse over them.

The service is offered to the ham community free of charge. If you are using this component as part of your webpages, I would like to hear from you!

More info


Disclaimer: This service is provided "as is". Use at your own risk.