The following information has been sent to me and gathered from
different sources. There is some conflicting information on Diaphone
types as well as PSI and CFM numbers. In these cases, this info
should serve only as a reference, and not taken as the gospel so
to speak. We would hate to hear of any damage caused to these great
horns, and we in no way accept any responsibility for any damages
that do occur.
This page has been divided up into categories for
provide easier navigation
Info and Resources
| Pressure Info | Piston
Stator and Pitch Info
Diaphone Restoration Project - An off-site link to a
project by Adam Smith
Parts Pictures #1 - An off-site link to
photos by Brett Jones
Parts Pictures #2 - An off-site link to
photos by Brett Jones
Literature. Donated By Jim
Armstrong, and scanned by Adam Smith. .PDF's were created by
The ones marked _print are 180dpi versions, 1530 x
1980 pixels for printing out at decent size. The _web versions are
the same files shrunk to 720 x 932. .PDF's are in their own
folder within the main literature directory.
The Diaphone warning horn is powered
by pressured air. They are well over 80 years old and are
capable of producing 1 second blasts at one half second intervals. Most reports
say the Diaphone can be heard about 6 miles with optimal conditions
(terrain, tall buildings, atmospheric conditions).
Mike Maderia, President of Maderia Warning
Systems, Garwood NJ says...
”I am the alarm superintendent of the Boro of Garwood NJ. We originally had 2
diaphones on the original firehouse. When the new firehouse was built in 1982
the town decided that we would use a electronic siren/horn. In 1998 it blew up
and then the long wait between the mayor and council and the fd in what to do.
They then decided to purchase a federal modulator siren that was supposed to
have a “air horn” sound. Well it did not, so it was taken down. This went on
over a 2-year period and a new chief. So it was decided that I would install a
diaphone air horn. I had been collecting Gamewell alarm stuff for some years now
and had a extra horn but it was not in the best condition. The piston was badly
scored and the projector was smashed. But I said that I can make this new again.
I am a pipe organ builder by trade, just like Robert Hope Jones, so I made a new
copper projector, made a wood pattern of a piston and had it cast, then I
machined a the blast of the horn can be heard about 7 miles away. The colder it
is the better the sound. I run ours at about 48 psi. I want to make sure that I
hear it when I am sleeping and I can.”
Mike says that he can make new pistons and copper
projectors for diaphone horns. If anyone is interested please email
me, and I will facilitate the contact.
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