Has anyone some pictures of the inner parts of a AHOOGA Horn? I think I get so far, how it works- but would like to see some details.... The problem is- there are not common in Germany, so the cance to get one and take a closer look is verry small.
I think there's a good cutaway in 1928 and maybe again in 1932 service bulletins, if someone can post from that... Basically, in the flange where the bell projector front bolts to the part housing the motor there's a spring steel flat diaphragm, as big around as the total horn at the flange. There's a hardened steel stud at the center of the diaphragm and the motor rotates a wavy serrated wheel against the stud...from my memory. No book here. The motor is quite large and powerful, and there's lots of force required because of heavy load between the rubbing parts. The distinctive sound is caused by the change in tone as motor spools up against load then dies down when power is cut. On 12 V, the thing spools up instantly, and the sound is a sudden and very load roar...needs a resistor to slow things down a bit.
Not a genuine Spartan or Klaxon but they work the same on the noisy end. The serrated wheel runs over the pin in the drum head.
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