Over the past year a number of people have asked me about the MST400 I use on activations and portable. The MST400 from OzQrp has proven to be a fine starter kit radio for SOTA activations. Here is the eham review. As of May 2017 I’ve activated 62 VK3 summits (over 400 SOTA activator points) exclusively with this rig. It is the radio in all of the summit photographs on this blog. Monoband, SSB, 5 watts RF output, about 100mA draw on receive and three quarters of an amp on transmit, a DDS VFO (AD9834) for accurate frequency setting and digital dial. It is lightweight and reasonably sized, given that you assemble it yourself with no surface mount parts. The receiver design is an uncomplicated SA612 superhet, 10MHz IF, and is more than adequate in the low noise mountain setting.
I built the first generation rig, from mid 2013. Since then, Leon VK2DOB has updated the design twice, and the latest kit, the Mk III, has audio derived AGC, an additional audio filtering stage, pluggable band modules for band selection, and other circuit improvements. Peter Parker’s review is here. There is a growing cadre of kit builders showing off their MST craft on YouTube. The MST Mk III is highly recommended for anyone wanting a kit building experience with thru-hole components, and a minimum of alignment and debugging fuss.