Wed Aug 15, 2012 2:52 am
Hmm...a siren on a siren on a siren...
Someone on this board had a single-tone versions of this siren with 12 ports. It may have been built by the US Navy, but more than likely, it was commissioned by them through Hedberg. My guess is Hedberg because these have only been seen in northern and central California, and that company had many designs. I'd be willing to bet that this is a photo of the inside of Hedberg's San Jose factory.
If you look closely, you will see the strange, flared-out motor cover. These are coding sirens, and the siren without the cover shows the mechanism. There is a large solenoid and a linkage going into the left rotor, and no doubt the same thing on the other side. Could be a brake, or perhaps the stator has a rotating cover of some sort. Rotating the air intake would effectively muffle the siren.
I have also seen a photo of a dual-tone siren like this, without the projectors. Apparently a dual-tone version of this would sound an octave interval like a Sterling/Sentry, except a fifth lower (think a Model 5 plus an octave lower).
Lex orandi, lex credendi, lex vivendi.