(I'm resending this message. Somehow the "wayback machine" took my computer back to June 3rd.)
Maybe you were thinking of a "Coaxial Line Stretcher"? Look at: <http://www.hirose.co.jp/cataloge_hp/e35500029.pdf> These keep a constant impedance of 50 ohms, but allow you to adjust the length of the cable. 73, Joe, K1ike
