Left: GMRT 325 MHz radio contours of the emission from A 1300 at the resolution of 27.6′′ × 18.1′′, p.a. 43°, overlaid on the grey-scale full-resolution image (14.0′′ × 8.8′′, p.a. 8°). The 1σ noise level of the contour image is 0.6 mJy beam^-1. Red contours start at 1.8 mJy b^-1 and then scale by a factor of 2. The 1σ noise level of the grey scale image is 0.45 mJy beam^-1. Individual radio galaxies are labelled following the notation in R99. Right: radio contours of the central cluster region after subtracting the discrete radio sources (the green crosses mark their location). The restoring beam is 28.0′′ × 28.0′′, p.a. 0°. The 1σ is 0.5 mJy beam^-1. White contours start at 1.5 mJy beam^-1 and then scale by a factor of 2. The − 3σ level is shown as red dashed contours.