LESSONS OF SINGING
The voice of the ZIS-110 had special requirements.
The Soviet limousine "sang" a set of three sound signals, differing in the shape and size of the "snails" - amplifying the sound of the resonators. The instruction manual prescribed: “The sound of the signals must be melodious and clear” and “… in the major triad, between the sounds of the high and middle tones, there must be a small third, and between the sounds of the medium and low tones a large third.”
Over time, the elasticity of the membrane and the anchor spring (see. Fig.) Decreased and ZIS had to "clear the throat."
To adjust, the signals were usually dismantled from the car and given to a specialist with a musical ear. Including the "horns" in turn, he determined which of them required intervention. To adjust - change the oscillation frequency of the membrane - removed the cap and, loosening the upper nut of the spring, rotate the bottom. Clockwise rotation increased tonality, counterclockwise rotation decreased. To listen, the cap was returned to its place. Often this procedure had to be repeated several times.
In addition to tonality, changing the strength of the current, corrected the volume of the signals. According to the instructions, at a distance of 1 m from the car, the sound intensity should be at least 110 dB (!). It is not surprising that this entire “orchestra” consumed a current of 40 A. I wonder how the expert’s musical ear stood the test. To adjust, unlocking, rotated the nut that opens the contacts.
The signals were serviced at each maintenance, after 9000 km: they cleaned and washed the contacts, if necessary, regulated