A piece of amateur radio jargon!

Here's a breakdown of the text:

* `08:21` is the time of transmission.

* `JM8NSW/8` is the call sign of the operator, indicating they are operating on 8 MHz (a frequency band). The prefix "JM" likely indicates Japan, and "8NSW" is their unique identifier. The "/8" suggests they are operating with a power output of 8 watts.

* `JP-1013` is the geographical location of the operator, specifically Makomanai Prefectural Park in Hokkaido, Japan (as indicated by "JP-HK", which is Hokkaido's ITU region).

* `7005.4 CW QRT.tnx!` is the actual transmission content:

+ `7005.4` is the frequency being transmitted on (in this case, 7.0054 MHz, but it looks like there might be a typo and it should be around 7.005 kHz or so).

+ `CW` indicates that the operator was transmitting using Continuous Wave (or Morse code) mode.

+ `QRT` is shorthand for "Quit Radiating, Transmitter". This means they are shutting down their transmitter.

+ `tnx!` is a polite way of saying "thank you" in amateur radio jargon.

In summary, the operator (JM8NSW) was transmitting on 7 MHz CW from Makomanai Prefectural Park, Hokkaido, Japan, and they're now shutting down their transmitter.