Good evening Darren

This relates to the old system of radio signal frequencies, prior to satellites etc.
The old distress frequency for ships until about 2010 was 500 kilohertz, previously kilocycles, which in old money was 600 metres.
So, to convert, 300000 divided by 500 equals 600 metres.

Your 986 metres becomes 302.5 kilohertz (cycles).

Happy listening

Phil