Radiocommunications on 3.7 MHz during the daytime for short distances.

Experiment for the radio communication in amateur band 80m (3.7 MHz) during the daytime for short distances (up to 45km). Of course in the field.
During the experiment, I set the first radio station in the fields (base camp), and depart from it at different distances, establish a connection with the second station on the night HF 80m band, but in the daytime.
The experiment uses except for single-sideband modulation (LSB) also amplitude modulation (AM).
Used radio station - Yaesu FT-897.
Frequency - 3710 kHz.