The Siren Board

Hi Guys,

This is my first post here and as a total newbie my knowledge of sirens is very sparse.

What I would like to do is build a full size working replica of the English WW2 Gents air raid siren most likely in the 10/12 configuration. As of such I need the specs like rotor diameter, width, stater port width etc. The main aim is it has to sound like an original.

I have nearly finished my miniature prototype 10/12 port siren with 45mm rotors which I have made on a mini lathe and milling machine. Once this one is done I would like to make a start in a full size one.

Thanks,

Jaz

That's really impressive! Gents also made a three-tone siren which had dual-tone rotors of 10/12 and 10/14, if I remember correctly.

For the correct pitch you'll need a 2800 RPM motor

Cool! Are you going to make a video of the mini replica?

Daniel wrote:That's really impressive! Gents also made a three-tone siren which had dual-tone rotors of 10/12 and 10/14, if I remember correctly.

No, the gents 3 tone was 10/12/15 port.

Thanks for your responses guys.

With the UK sirens I came across this site last night with really good photos and one with a ruler so I will be able to work out the size. http://www.ringbell.co.uk/ukwmo/Page216.htm

When the mini siren is finished I will make a video of it working. I have had it running with a brushless motor from an RC plane and spinning at full throttle it hit 115.1 decibels at 1m. Full throttle RPM is most likley over 10,000 rpm which is way to fast for comfort.

At the moment I am making a reduction drive to slow the siren down an improve the up/down sensitivity. I should have the mechanics of it finished in the next few days.

Jaz

Now that is noyyce! 8)