J-B-T Instruments Inc 1943 vintage electrical ad sound tune meter

<p>Original 1943 electrical trade vintage ad for <b><span style="font-size: 14px;">J-B-T INSTRUMENTS, INC.&nbsp;&nbsp;</span></b>Main office and plant was located at 459 Chapel Street, New Haven, CT.</p><p> Manufacturers of Vibrating Reed Frequency Meter. Model 33-F for 400 Cycles.</p><p>Sound your "A". We're going to tune a 400 cycle meter.</p><p>Pitch pipes or ordinary tuning-forks are good enough for musical instruments where human error is expected, but not for electrical instruments. Tuning-fork electronic oscillators of our own design are used to calibrate J-B-T&nbsp;Vibrating Reed Frequency Meters because this is the most scientific, most accurate method we know of. Reeds are calibrated twice - once before assembly and later in the completed instrument. Before shipment each instrument is given a final check for accuracy of resonance.</p><p> Has product images, illustrations, descriptions, applications and specifications to provide extensive product details. </p><p>Unbound from a 1943 electrical engineering magazine, this unique old one-page advertisement would display beautifully matted and framed. Nice graphics.&nbsp;World War 2 propaganda. A fabulous addition to your retro electrical library.<br></p>