November 2012.. The Argonaut 509 control boards. Actually.. the green board in these pictures may or may not have been manufactured by Ten Tec. It may have
been a copy. Another thing..the green board may have come from an Argonaut 505. During the manufacture of Ten Tec Argonauts during the later 1970s..there
was a cross over time when the 505 was discontinued and the 509 commenced. Some 509s started out with a control board that had a reed relay on it ..then
later..the Argonauts began using solid state switching.