This looks interesting, it’s an amp by a US amateur based on those $20, 70W kits available on ebay with a built in auto-tuner and some other goodies. There’s no kit, but all the design files are available as is the firmware. The final power was dropped to 50W to avoid IMD, and it seems to be small enough to come along for non-technical expeditions.
http://ae7eu.com/index.php/quickie-50-amplifier/
