This appears to be a radio transmission message in a format commonly used by amateur radio operators. Let's break it down:

* `06:19`: The time of the transmission, which is 6 hours and 19 minutes.

* `JE3USR/P`: This seems to be the call sign of the transmitting station. In amateur radio, call signs are used to identify stations, and they typically consist of a combination of letters and numbers. `J` indicates that the station is located in Japan, while `E3USR` is the specific call sign.

* `/P`: This suffix indicates that the transmitter is portable (as opposed to being installed at a fixed location).

* `on JP-1942(Ken-ei Fukushi Prefectural Park, JP-NR)`: This line seems to indicate the location of the transmitting station. `JP` again confirms that it's in Japan. `1942` might refer to a specific geographic identifier or grid square. `Ken-ei Fukushi Prefectural Park` is likely the name of the park where the transmitter is located, and `JP-NR` probably indicates that this location is within the Japanese national parks system.

* `21074`: This is the frequency at which the transmission was made, expressed in kilohertz (kHz) units. However, given the format of the message, it's more likely to be a Morse code indicator or a number used for some other purpose related to amateur radio operations.

* `SSB`: This stands for Single Sideband, which is a mode of radio transmission that allows for efficient and clear communication over long distances. It's likely used here as an indication of the type of transmission made by JE3USR/P.

* `Thanks[VK6MFP]`: This part appears to be a message acknowledging the reception of the transmission from VK6MFP, which is another amateur radio call sign.

So, in summary, this message announces that a radio station with the call sign JE3USR/P has transmitted a Single Sideband signal at 21074 kHz from Ken-ei Fukushi Prefectural Park in Japan, and thanks another operator, VK6MFP, for receiving it.