SEA GAIN EFFECT FOR MW DXING

    Do you know sea gain for MW reception ? The sea gain is the additional signal gain when one or both terminals is situated near the sea, but it does not apply to propagation over fresh water.
Therefore, You can enjoy MW DXing much better at a sea cliff or a sea coast than that in inland area.
   The sea gain was found long time ago by P.Knight, a researcher of BBC around 1975 and the sea gain was defined with some formulas in the ITU-R recommendation P.1147-4 (Click)
" Prediction of sky-wave field strength at frequencies between about 150 and 1700 kHz". The sea gain depends on the distance between transmitting point and receiving point  and frequencies. The graph below is  an extract from the ITU-R recommendation.  The curve A is for MW band. For MW DXing, the propagation distance would be more than 6000 km then the sea gain is expected about 10 dB. This means your S-meter goes up about 3 scales(I mean when  your S-meter indicates S-1 at a inland area, you can expect S-4 signal at a cliff or a coast.)   You should not ignore this effect for much better MW DXing.

   Some papers written by P.Knight et al of BBC are downloadable. The clickable links are as follows.

The influence of the ground and the sea 

on medium-frequency sky-wavepropagation.(1968)

LF and MF propagation: An approximate formula for estimating sea gain (1975)

LF and MF propagation: The effect of earth curvature on sea gain (1976)

    There are very few articles of MW DXing that report about the sea gain. But we can read a very interesting article titled " Inland versus seaside MW DXing".(Click)

written by John Plimmer from South Africa who is one of famous MW DX information web site DXing info Community.   ((http://www.dxing.info/)

     The following video shows some reception scenes of KKOL (Seattle) on 1300 kHz at a cliff in Chiba, Japan on Sep.22 2016.  The audio clips and pictures are provided for my blog by one of MW Japanese DXers, Sawapon (Sawapon is his nickname.) Sawapon's blog(Japanese) is here (click).. We conducted a DXpedition with other MW DXers on the same day. The signal of KKOL propagating 7700km from Seattle was received well even with a portable MW radio thanks to the sea gain. 

THE MOVIE " IN THIS CORNER OF THE WORLD"

   This movie "In this Corner of the World " that was supported by crowd funding of this cartoon fan including me, has been just released on Nov. 12, 2016.   Most of movie theater seemed to be full yesterday.  As one of supporting fan, my name is listed at the end credit of this movie. This anime depicts ordinary people's life in Hiroshima during the Second World War through the life of heroine "Suzu".  This movie was made with accurate historical investigation by the movie staffs including the director Sunao Katabuchi. This investigation gives the anime strong powers of persuasion. 

   This movie doesn't insist on vigorous opposition to the war in us directly and dramatically. This movie just shows us the life of people in laughs, sadness and loves simply with good tempo in about 120 minutes. I was never bored at all. The color of each scene and each expression of characters in this movie was so excellent and impressive. 

    During the movie, to be honest, I sobbed. I could mull the life of people during the war in the past comparing to my life over in my mind. It is difficult to explain my feelings with words, but I was watching this movie remembering  the spent days with my grand mother and grand father in the countryside.  Other audience were also sobbed too, but we felt hopes, happiness and warmness at the last scene of this movie.

    After the movie  I felt that I was standing in this "little" corner of the world that had been made by ordinary people who live in the past.

    I hope this movie will be introduced to all over the world in appropriate languages. I recommend all of my foreign friends to watch this movie to understand Japanese ordinary people's life in the past and Japanese heart that has been passed down calmly from our ancestors to us who are living in the present world.

  

Ａ support member meeting in Tokyo with the production staff of this movie on Aug.4 in 2015

(The man at the center of front row is Director Sunao Katabuchi.) 

This movie is also introduced on NHK World's VOD .

APPLICATION OF GOOGLE MAP FOR MW DX LOG

    I am evaluating Google map for my MW DX logging. The map below shows a distribution of received MW stations of U.S. on TDXC DXpedtion conducted at a coastline of Chiba prefecture in Japan on Sep.22,2016.  With your mouse, you can freely click each orange dot to see the reception sound link for each received station and You can also see the distribution of the stations. You can move the map freely too. Most of the received stations are located close to west coast.      I am wondering why I couldn't receive more inland MW stations. I guess this result is related to sea gain effect at transmitting site.