Kinda thought so! They were scarce and pricey 40 years ago! When the Sun SuperTach came out, it obsoleted the earlier-type tach with the transmitter, as I remember. It was one of the first solid-state tachometers on the market.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!