Island FM

FM · DAB

On the map

Where Island FM is radiated from — 4 transmitters [V], Ofcom's published positions. This says nothing about how far the signal reaches; it is not a coverage map.

FM

2 FM transmitters, strongest first. ERP is published per polarisation; a dash means nothing is radiated in that plane.
Transmitter	Nation	Frequency	ERP (H)	ERP (V)	Height	RDS name	PI code	Area
Les Touillets	England	104.7 MHz	250 W	1.0 kW	46 m	IslandFM	C6B2	Guernsey
Fort Albert	England	93.7 MHz	—	10 W	20 m	IslandFM	C6B2	Alderney

DAB

The ensembles carrying this station. Every transmitter of an ensemble carries all of its services, so the transmitter list belongs on the ensemble's own page.
Ensemble	Block	EId	Transmitters	Broadcast as	Area
Channel Islands	12A	C1CF	3	Island FM	Channel Islands

Radiation pattern

Les Touillets publishes the strongest FM signal for this station with a shape on record — where it is carried elsewhere too, this is not necessarily theirs.

Radiates most strongly toward the east (110°), as published by Ofcom.

More detail

Each ring is 10 dB of attenuation below the pattern's own peak; the outer rim is the peak itself and anything 30 dB down or deeper is drawn at the centre rather than off the edge of the chart, so a very deep null reads as “weak” and not as a hole in the picture. The shape says which direction radiates harder relative to the mast's own peak, not the absolute field strength there or how far it reaches — that is what the coverage map and the postcode lookup are for. Solid is horizontal polarisation, dashed is vertical.