1. Department of Physics and Electronics, Rhodes University, PO Box 94, Grahamstown 6140, South Africa
2. Ghana Space Science and Technology Institute, Ghana Atomic Energy Commission, P. O. Box LG 80, Legon, Ghana
3. Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
4. SKA South Africa, 3rd Floor, The Park, Park Road, Pinelands 7405, South Africa
5. Department of Physics and Astronomy, University of the Western Cape, Bellville, Cape Town 7535, South Africa
6. Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver V6T 1Z1, Canada