Via the G8JNJ SDR receiver located in the SW UK. 28975 kHz FM NFM 28,975 28.975.0 MHz.
I managed to get a video clip of the activity on 28.975 MHz
https://www.youtube.com/watch?v=lDmLbPtLLJUNoted these guys on numerous additional frequencies, including:
27.500 MHz FM
27.525 MHz FM
27.575 MHz FM
27.600 MHz FM with heavy QRM from SSB CB signals and UK FM CB ch. 1 - freq 27.60125 MHz FM
27.750 MHz FM
27.775 MHz FM
27.875 MHz FM with QRM from Russian taxi cab dispatcher YL land mobile comms on 27875 FM
27.925 MHz FM
27.975 MHz FM
28.025 MHz FM
28.175 MHz FM
28.225 MHz FM
28.350 MHz FM
28.375 MHz FM
28.725 MHz FM
28.775 MHz FM
28.825 MHz FM
28.875 MHz FM
29.000 MHz FM
29.150 MHz FM
29.625 MHz FM - QRM from legit ham signals
29.700 MHz FM
29.750 MHz FM
29.775 MHz FM
29.825 MHz FM
29.875 MHz FM
29.925 MHz FM
29.950 MHz FM
30.075 MHz FM
30.125 MHz FM
30.150 MHz FM
30.175 MHz FM
and many more above 30 MHz