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Please note: 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


General Diaphone Info and Resources

Diaphone Types | Pressure Info | Piston Stator and Pitch Info


New Diaphone Literature.  Donated By Jim Armstrong, and scanned by Adam Smith.  .PDF's were created by SeanS

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.


Please click on any image below for a full size pic. 

Below: Old Gamewell brochures, and technical information.


Image is courtesy of Gary & Liz Gelfman  Image is courtesy of Gary & Liz Gelfman  Both Images Left: Courtesy of Gary & Liz Gelfman 
This is a scan of a document that I am the owner of.  This is a scan of a document that I am the owner of.  This is a scan of a document that I am the owner of.  Courtesy of Jason at
        Above: Courtesy of Jason at
Image courtesy of Gary Peterson Image courtesy of Gary Peterson Image courtesy of Gary Peterson Image courtesy of Gary Peterson Image courtesy of Gary Peterson

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Thanks to Gary Peterson for the images immediately above.

Image courtesy of Adam - Image courtesy of Adam - Image courtesy of Adam - Image courtesy of Adam - Images to the right courtesy of Adam.

Above: Patent information and diagrams

More Patent information .JPG's (coming soon)

Page Last Modified 03/1/15 01:36

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