. . "They arestill available, though: Dan's Small Parts and Kits sells several types of NOS (new, old stock, meaning unused but not recent manufacture.) And I happen to havea couple hundred in a jar somewhere...The 40673 was a particular RCA part that the ARRL chose as a \"standard dual-gateMOSFET because it was rated to 500 MHz, but especially below 100 MHz just about any of the other similar parts" . .