Modulators?

https://youtu.be/HmhpmkeptXE

In 1950, San Jose pulled their sirens stored since WW2 out of storage. The beat up looking Model 7 at the left was at Monterrey & Alma. 4 Hedberg built sirens to the right.


https://imgur.com/a/PH2E6fk

A Super Sirex at 26:42 here:

https://youtu.be/qRFZnN4_TRI

It was a Bullard siren.

Many years ago, speaking with one of J. N. Hedberg's workers, said they had a big siren, like the ones in my avatar, where the rotor/impeller maker had ran out of metal for the casting, had to melt more metal, then finished the casting. It also exploded during testing.

A Bullard siren exploded during testing, in 1941:

https://www.newspapers.com/article/cont ... 125059343/

There were 5 of the Victory version in San Francisco: https://www.newspapers.com/article/the-san-francisco-examiner-large-sirens/125059378/ A Big Joe in Pomona CA: https://www.newspapers.com/article/99094469/ 3 in Spokane WA: https://www.newspapers.com/article/100646360/spokane-chrysler-locations/ 5...

Interesting, that one is a Thunderbeam.

https://goo.gl/maps/bumbiXMe724nKqPw9

OK, found a news piece that San Mateo CA bought at least 2 EOWS 1212's in 1987: https://www.newspapers.com/article/times-tribune-san-mateo-new-sirens/125059794/ The news article does not say where the other 4 were to be located. I can't find the one by the Library. Confirmed one of them: https://goo...

Looks like they installed a used Victory siren in 1968:

https://www.newspapers.com/article/the- ... 125059614/

New York City had Chrysler Victory sirens in their early system:

https://www.newspapers.com/article/the- ... 125059417/