practical limit on $\delta$. We therefore set the DM index to $\delta = -2$.

![image](Fig7.pdf){width="5.0"}

![image](Fig8.pdf){width="5.0"}

Localisation
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All 3 FRBs were discovered while following up known sources, which were at “bore-sight”, and thus centred on Beam 177. We localise each FRB’s position on the sky, using the angular separation between the FRB’s position in fan-beam space from the bore-sight fan-beam. The 1$\sigma$ uncertainty in the direction of the semi-major axis is defined by the primary beam ($\sim 2.8^{\circ}$) while the uncertainty in the semi-minor axis is controlled by the fractional S/N measured from the adjacent fan-beam detections. For FRBs detected in adjacent fan-beams, we perform a simple linear interpolation based on the S/N to localise the event in the fan-beam grid. For the FRB with a single fan-beam detection only, we assume the centre of the fan-beam for the localisation. This allows us to construct a trace on the sky relative to the bore-sight (RAJ, DECJ), taking into account the meridian angle of the observation at the time of the FRB, and the known, slight skew and tilt of the East-West arms relative to true East-West and horizontal. The trace is a strong function of the hour angle of 