Note
Ham Radio, Jan 1974, p. 70.
Ham Radio, Jun 1974, p. 88.
Ham Radio, Dec 1974, p. 94 ("B" version)
Ham Radio, Jan 1975, p. 66. (shown with handle and telescoping antenna)
The ECM-5(B) modulation meter assisted in the adjustment of FM transmitters.
The model 5 covered from 52–450 MHz. The model 5B expanded this slightly to 25–500 MHz. Model 5 reards read peak deviation from 0–15 kHz. The "B" version reads from 0-7.5 kHz. It was crystal-controlled and had an internal battery supply. The ECM-5(B) was manufactured by the ECM Corporation in Evansville, Indiana.
The ECM-5(B) FM modulation meter closely follows the circuits used in professional equipment except that frequency is crystal controlled. The frequency selecting crystals are the subminiature, third-overtone type used in many FM receivers of the day. These crystals were chosen for their low price and availability.
The peak reading meter has a special time-constant circuit that causes the
needle to deflect upscale rapidly and downscale slowly. This allows the needle to follow voice peaks and increases the accuracy of readings when checking deviation using voice modulation.
Other features include a built-in or external antenna, all solid-state construction, battery powered by inexpensive AA batteries, and a battery condition indicator.