"A Simple and Accurate QRP Directional Wattmeter", in Feb. 1990 QST fits
the description. It also appeared in several ARRL Handbook editions
shortly after the QST article was published, and in some reprint
publications like ARRL's _QRP Classics_.

Roy Lewallen, W7EL

Richard wrote:

Does anyone have a ny designs for a (low) power meter that would read powers
of up to 1w (down to say 50mw or even lower) up to and inc. 6m?

Rgds
Richard SO5GB