Friday, July 24, 2015

Introducing VOACAP DX Charts

The VOACAP DX Charts service has been upgraded in August 2018. This service uses much of the same technology & ideas I created for the VOACAP Propagation Planner such as:
  • interactive propagation charts that show the QSO probabilities and signal power (hover the mouse over the table cells to see the values)
  • graphical presentation of sunrise and sunset times to help predict low-band openings (hover the mouse over the 'TX' and 'RX' labels on the bottom left of the tables to see the exact sunrise and sunset times in UTC)

An example DX propagation chart.

I have deliberately kept the layout of the results page to a bare minimum to allow the user to copy the charts to word processing, and make them pretty for printing.

To use this service, the user only needs to know his/her Maidenhead grid locator and press the "Run!" button. If you do not know your grid locator, I have created an easier-than-the-easiest map application to help you find your grid locator : . Just zoom into your location on the map, and your coordinates and grid locator are readily visible on the top part of the map.

Furthermore, if you wish to tweak the default antenna selection by band, you can do so, and even save your selections (click "Save setup"), together your grid locator, for later use. Also, swapping the antenna selections between TX and RX is available with one click!

And, as a bonus, the option to set the sporadic E layer (Es) has been made available. Use this if your location could be under the influence of the sporadic E, e.g. during the summer in the Northern hemisphere.

For the predictions, I have assumed that, on 20M to 10M, the DX uses a 3-ele Yagi at 10 meters AGL, and on low-bands a 1/4 vertical over a good ground. On the user's side, a 3-ele Yagi at 20 meters AGL for 20M to 10M, and a 1/4 vertical over a good ground are assumed. The TX power is assumed as per the DXpedition in question.

The DX sites are currently being updated on a monthly basis, or on an "as-needed" basis. Please let me know if you find bugs, or want more DX sites added to the list.

73 Jari OH6BG


  1. After the Point-to-point prediction, the Coverage Area map, the blog, the Planner, with this DX Chart VOACAP online - and always free - becomes a must for all fans of propagation. Congrats to Jari Perkiömäki, OH6BG/OG6G, and his team who support this new version !
    About VOACAP read :

  2. ANy chance of building charts for the guys currently in A25? I haven't heard them at all as yet, neither LP nor SP.

  3. Hi Gary, yes the charts have been updated accordingly :)

  4. HI Jari!
    Can you add my next dxpedition 15-27.03.17. S21GM
    73, Yuris/YL2GM/

    1. Absolutely, thanks for the heads-up!
      73 Jari OH6BG

    2. S21GM predictions now available at

  5. Hi Jari,

    Could you add PG400TH predictions as well?
    Please have a look at

    Tnx and keep up the good work.

    Jan, PA2P

  6. Hi Jan, please contact me directly via email, and let's talk.
    73 Jari OH6BG

  7. Hi! Jari

    Kindly add our coming dxpedition 29/4-1/5/2017 at Satang Besar Island, OC-165. Grid: OJ51BT. Callsign: 9M8RC

    de 9W8DEN