Date: 1959

The lektro-tuner is probably tube operated. .

What Conn said in 1959:
Bb and A actually sound on the Lektro-Tuner and are continuous so that the "listener" can hear the tone for the entire time it is running. More dependable than tuning bars or forks and reasonable enough to have in every music room. Has both volume and tone change to satisfy any teacher. Adjustable range from A435-A445. Lightweight, only 6 lbs 2 oz. Shipping weight 7 1/2 lbs. Can be used with any outlet of 110 volts 60 cycles.