{"id":330,"date":"2026-08-07T08:10:17","date_gmt":"2026-08-07T08:10:17","guid":{"rendered":"https:\/\/www.mdxc.support\/9t0md\/?p=330"},"modified":"2026-08-07T08:10:17","modified_gmt":"2026-08-07T08:10:17","slug":"voacap-propagation-prediction-available-for-9t0md","status":"publish","type":"post","link":"https:\/\/www.mdxc.support\/9t0md\/2026\/08\/07\/voacap-propagation-prediction-available-for-9t0md\/","title":{"rendered":"VOACAP Propagation Prediction available for 9T0MD"},"content":{"rendered":"\n

VOACAP Propagation Prediction now available for the 9T0MD DXpedition<\/p>\n\n\n\n

Most European DXers believe that when a DXpedition is active from Africa, the only thing to do is point the antenna south and wait for the spots to appear on the DX Cluster.<\/p>\n\n\n\n

Well\u2026 they are not entirely wrong. From an ionospheric point of view, Africa is indeed Europe’s “backyard”. However, especially on the low bands, being on the right band at the right time can make the difference between an easy QSO and hours of frustration.<\/p>\n\n\n\n

The same applies to stations outside Europe. For DX hunters in North America, South America, Asia and Oceania, knowing in advance which bands are expected to open toward the Democratic Republic of the Congo is extremely valuable, often allowing them to work 9T0MD before the inevitable European pile-up takes over.<\/p>\n\n\n\n

The best way to determine which band offers the highest probability of success is by using ionospheric propagation predictions. Fortunately, there is no need to be an ionospheric physicist. Thanks to the outstanding work of Jari, OH6BG, the amateur radio community has access to one of the world’s most respected HF propagation prediction systems: VOACAP.<\/p>\n\n\n\n

VOACAP (Voice Of America Coverage Analysis Program) was originally developed for the Voice of America international broadcasting service to predict worldwide HF radio coverage. Over the years, Jari has continuously refined and adapted the software specifically for amateur radio operators, making it an invaluable planning tool for both DXpeditions and DX chasers.<\/p>\n\n\n\n

For those wishing to explore the theory behind HF propagation, the official VOACAP website offers extensive documentation, tutorials and technical presentations. However, for most operators, the integrated prediction tool provides everything needed with just a few clicks.<\/p>\n\n\n\n

To help maximize everyone’s chances of working 9T0MD, we have integrated a dedicated VOACAP prediction page into the official DXpedition website. By selecting your location and the desired band, you can quickly identify the most promising propagation windows throughout the expedition.<\/p>\n\n\n\n

This allows operators to:<\/p>\n\n\n\n

Identify the best bands for their geographic area.
Discover the most favorable opening times.
Plan their operating schedule more efficiently.
Reduce unnecessary calling during poor propagation periods.
Increase the probability of completing a successful QSO with 9T0MD.<\/p>\n\n\n\n

Remember that VOACAP provides probability forecasts, not guarantees. Solar activity, geomagnetic disturbances and other ionospheric variations can always influence real-world conditions. Nevertheless, the predictions are remarkably accurate and represent one of the best tools available for planning successful DX operations.<\/p>\n\n\n\n

In the following section, we will briefly explain how to configure the VOACAP interface and interpret the prediction charts to obtain the most useful information for chasing 9T0MD.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

First of all, you need to tell the software where you are operating from by entering your QTH<\/strong>. Simply type your Maidenhead Grid Locator<\/strong> into the dedicated field. If you don’t know your locator, click on “Your Grid Locator”<\/strong> next to the input box to access the built-in VOACAP QTH Locator<\/strong> utility, which will help you determine it.<\/p>\n\n\n\n

Once your location has been entered, you can proceed with the remaining settings. We recommend leaving the SSN<\/strong> value at its default setting of -1<\/strong>. This allows VOACAP to automatically retrieve the most up-to-date Sunspot Number (SSN)<\/strong> data available, ensuring the most accurate propagation predictions.<\/p>\n\n\n\n

Likewise, leave the Min TOA<\/strong> (Minimum Take-Off Angle<\/strong>) at its default value of 3 degrees<\/strong>. This setting represents a good compromise for most amateur radio stations. Operators with exceptionally low-angle antenna systems may experiment with lower values if appropriate.<\/p>\n\n\n\n

Next, select your transmitter power<\/strong>. VOACAP provides four standard power levels: 5 W, 100 W, 500 W and 1000 W<\/strong>. Although intermediate values are not available, these levels adequately represent the majority of amateur stations.<\/p>\n\n\n\n

The inclusion of the 5 W<\/strong> option is particularly appreciated by QRP enthusiasts<\/strong>, allowing them to identify the periods during which propagation conditions offer the highest probability of completing a contact with 9T0MD<\/strong> despite using very low power.<\/p>\n\n\n\n

The next step is to configure the antennas. The 9T0MD transmitting antenna system<\/strong> has already been pre-configured within the prediction model, so you only need to specify your own antenna<\/strong>. Choose from the available list the antenna type that most closely matches your station on each amateur band.<\/p>\n\n\n\n

If you operate with a quarter-wave vertical<\/strong>, you can further improve the prediction accuracy by selecting the appropriate ground quality<\/strong>: Normal<\/strong>, Good<\/strong>, or Very Good<\/strong>, depending on your installation.<\/p>\n\n\n\n

Once all the required information has been entered, you’re ready to generate the propagation prediction. Above the antenna configuration section, you will find several analysis options. For most operators, the recommended choice is “Run VOACAP”<\/strong>, located on the left-hand side.<\/p>\n\n\n\n

The resulting page will display several propagation charts. The most important is the first graph, which illustrates the 24-hour probability of completing a QSO between your station and 9T0MD<\/strong>, showing both Short Path<\/strong> and Long Path<\/strong> predictions.<\/p>\n\n\n\n

These charts allow you to identify the best operating windows for each band, helping you decide when to call and significantly increasing your chances of working 9T0MD<\/strong> before the pile-ups become overwhelming.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

While the Long Path<\/strong> predictions are primarily intended for operators located farther away from the Democratic Republic of the Congo, they can also reveal surprising propagation opportunities for many regions of the world. VOACAP provides a wealth of operating information, but if you’re looking for a quick overview, the charts are very easy to interpret.<\/p>\n\n\n\n

As a general rule, red and dark orange indicate the periods with the highest probability of completing a QSO with 9T0MD<\/strong>, while yellow and green represent moderate chances. Light blue and white correspond to very poor propagation conditions, where making a contact will require exceptional propagation\u2014or a bit of DX luck!<\/p>\n\n\n\n

Don’t be confused by the TX<\/strong> and RX<\/strong> labels shown in the yellow header of the prediction charts. HF propagation is inherently bidirectional<\/strong>, and the prediction is always calculated using the transmitter power you selected<\/strong> in the input form, regardless of which station is formally identified as the transmitter or receiver.<\/p>\n\n\n\n

For operators who enjoy comparing different prediction models, Jari, OH6BG<\/strong>, has also made available two additional propagation engines directly from the 9T0MD<\/strong> website: ITUHFProp Short Path<\/strong> and ITUHFProp Long Path<\/strong>.<\/p>\n\n\n\n

Developed under the auspices of the International Telecommunication Union (ITU)<\/strong>, ITUHFProp<\/strong> provides an alternative mathematical model for HF propagation forecasting. Comparing its results with those from VOACAP offers valuable insight into expected band openings, allowing you to plan your operating schedule with even greater confidence.<\/p>\n\n\n\n

If you become interested in propagation analysis, we highly recommend exploring the VOACAP<\/strong> website, where you can generate predictions for virtually any location in the world<\/strong>, making it an excellent planning tool for future DXpeditions and everyday DXing.<\/p>\n\n\n\n

Finally, don’t overlook one of the most useful features provided by Jari. By clicking the “Run Map”<\/strong> button, VOACAP generates an Azimuthal Projection Map<\/strong> centered on your own station. The map displays the exact short-path and long-path headings<\/strong>, together with the distance to 9T0MD<\/strong>, helping you accurately point your directional antennas toward the expedition.<\/p>\n\n\n\n

A sincere thank you to Jari, OH6BG<\/strong>, for making these outstanding propagation tools freely available to the worldwide amateur radio community. They continue to be an invaluable resource for both DXpeditions and DX hunters alike.<\/p>\n\n\n\n

We wish everyone the very best of propagation\u2014and we look forward to working you from 9T0MD<\/strong>!<\/p>\n\n\n\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

VOACAP Propagation Prediction now available for the 9T0MD DXpedition Most European DXers believe that when a DXpedition is active from Africa, the only thing to do is point the antenna south and wait for the spots to appear on the DX Cluster. Well\u2026 they are not entirely wrong. From an ionospheric point of view, Africa […]<\/p>\n","protected":false},"author":2,"featured_media":332,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9],"tags":[],"class_list":["post-330","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-technicians"],"_links":{"self":[{"href":"https:\/\/www.mdxc.support\/9t0md\/wp-json\/wp\/v2\/posts\/330","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.mdxc.support\/9t0md\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.mdxc.support\/9t0md\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.mdxc.support\/9t0md\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mdxc.support\/9t0md\/wp-json\/wp\/v2\/comments?post=330"}],"version-history":[{"count":1,"href":"https:\/\/www.mdxc.support\/9t0md\/wp-json\/wp\/v2\/posts\/330\/revisions"}],"predecessor-version":[{"id":334,"href":"https:\/\/www.mdxc.support\/9t0md\/wp-json\/wp\/v2\/posts\/330\/revisions\/334"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.mdxc.support\/9t0md\/wp-json\/wp\/v2\/media\/332"}],"wp:attachment":[{"href":"https:\/\/www.mdxc.support\/9t0md\/wp-json\/wp\/v2\/media?parent=330"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.mdxc.support\/9t0md\/wp-json\/wp\/v2\/categories?post=330"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.mdxc.support\/9t0md\/wp-json\/wp\/v2\/tags?post=330"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}