QEI 691 FM Modulation monitor

Description

QEI 691 FM Modulation monitor. Condition is "Used".  The "display select" switch assembly was replaced with a new one a few years ago.  The unit has been on the shelf for about four years.  The unit was recently tested with an Orban 8400 stereo processor/generator with good results .  The calibration was checked about six years ago. All incandescent lamps have been replaced with 28 volt lamps to increase lamp life.  Has been tested on both the antenna level and transmitter sample level inputs using a frequency of 91.9 mhz.  The thumb-wheel switches are in good shape and have been lubricated with silicone.  This should not be needed again for several more years.  Contains the newer-style black or blue electrolytic capacitors instead of the older problematic grey or yellow ones.