From Alex Pettit 23/12/2025, published on SARA Mailing List, sara-list@googlegroups.com Performance Exceeds anything I’ve seen in the ‘out of the box’ beginner systems .. Post navigation Effect of small hardware changes on 1m class hydrogen line radio dishes on removing radio frequency interference (RFI). Design feedhorn to give an attenuation of 10 to 12 dB towards the rim of the dish.