Recently, the 2m DX propagation channel has been frequently observed. For example, last week, amateur radio operators from areas 1 and 2 in China were able to establish a direct frequency link with Japanese stations on 145.100 MHz. Furthermore, on July 3rd at 11:00 PM Beijing time, a station in Shijiazhuang, Hebei Province, received a signal from a radio broadcast in Longyan, Fujian Province (approximately 1500 km away), and the sound was particularly clear.
If you are interested in making QSOs with Japanese amateur radio operators via the 2-meter band (dx), you could try predicting propagation channels yourself using ionospheric prediction data.
First, we need to understand the concept of "ionospheric critical reflection frequency." This refers to the highest frequency of radio waves that can be reflected back along the same path by the ionosphere when vertically transmitted.
Please see the URL below, which provides predictions for some ionospheric critical reflection frequencies in Japan (if it doesn't open or loads slowly, use a proxy):https://wdc.nict.go.jp/Ionosphere/realtime/latest-fxEs.html
(The screenshot in the image above shows the page as it appeared at 3:00 PM Beijing time on July 4, 2025.)
In the table, the horizontal axis represents the region and the vertical axis represents time. We are particularly focusing on the prediction results for the first two columns (the first column is for Onna County, and the second column is for Shimabara County). These counties are located closer to the mainland of China and have higher reference value.
As we all know, the higher the density of the ionosphere, the stronger its ability to reflect/refract high-frequency radio waves. For example, during summer or periods with frequent solar flares, propagation in the 10m band is usually good, but at night, the density of the ionosphere decreases, so the refraction angle of the 10m wave may be so small that it penetrates through the atmosphere. Therefore, propagation in the 10m band is unstable, which is why "the ten-meter king is still there, but not seen today," as was said during solar maximum periods.
If the propagation in the 10 MHz band is quite good, it indicates that the ionosphere has a high density. In this case, DX propagation on the 6 MHz band should also be possible. Similarly, if the F8 signals received from distant locations on the 6 MHz band are strong enough to overload your BOX-6 receiver circuit, then DX propagation on the 2 MHz band is also likely. This is the principle by which amateur radio operators can accurately determine whether there is DX propagation on the 2 MHz band by listening to unusual F8 signals transmitted via FM broadcasting. If you want to use lower frequencies to predict DX propagation on higher frequencies, the closer the two frequencies are, the more accurate the prediction will be, and this also indicates that the propagation channel is stronger and more stable.
Therefore, if the predicted critical reflection frequency in the table is higher, it indicates a greater possibility of 2m band propagation. Typically, based on past experience, if this frequency exceeds 20 MHz, there is a high probability of 2m DX (long-distance communication), and this probability is very significant.
I learned about this website from Friend at JG2TSL, and I'm very grateful for his sharing!
P.S.: If you want to participate in 2m DX, please join this group. I'm also in it. This group is mainly for sharing and learning about 2m DX propagation information. The administrator says that there are too few people, so they encourage everyone to invite more members. So, if you have read this article, it means you are very interested in 2m DX QSOs, then you should definitely join the group [doge]
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