DSB transceiver circuits - 10m and 6m

Michele IZ8JJI has just sent me a link to a neat, very simple, DSB transceiver suitable for either 10m or 6m. It is from a Japanese magazine (CQ?). See http://www.cqpub.co.jp/hanbai/books/15/15061/15061_p.180-181.pdf

I am not sure of the power (milliwatts I think) but WHAT a neat circuit!