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Re: Scored A Sentry SS3/Defender

Posted: Thu Oct 11, 2018 6:21 pm
by Chem_Boffin_6589
DJ2226 wrote:
Thu Oct 11, 2018 5:22 pm
Chem_Boffin_6589 wrote:
Thu Oct 11, 2018 5:15 pm
Hello it's directional too. Never knew!
If I'm not mistaken all of the sirens produced by Sterling and Sentry are directional. The 3V8 and its derivatives and the 40V have directional rotors as well.
I've known Sterling Ms to have non directional rotors. I might need to check again given the Y-10 was a directional siren.

Re: Scored A Sentry SS3/Defender

Posted: Sat Oct 13, 2018 10:25 pm
by Travis
The later Sterling M's had directional rotors. Like I said earlier, this is the exact same rotor/stator assembly many of their sirens use. I am 99% the 3V8 has a directional rotor as well.

Re: Scored A Sentry SS3/Defender

Posted: Fri Oct 19, 2018 10:26 pm
by fire_freak_57
There is an inactive Defender in Medina County, Ohio as well, in Lafayette Township near Chippewa Lake. There are plans to replace that system with newer FS sirens in the future so that Medina County Sheriff’s Dispatchers can activate it directly via FSK as with the rest of the system. It’s been inactive since at least 2014. The 15V2T in that system is still active.

Re: Scored A Sentry SS3/Defender

Posted: Tue Oct 23, 2018 5:04 pm
by DJ2226
fire_freak_57 wrote:
Fri Oct 19, 2018 10:26 pm
There is an inactive Defender in Medina County, Ohio as well, in Lafayette Township near Chippewa Lake. There are plans to replace that system with newer FS sirens in the future so that Medina County Sheriff’s Dispatchers can activate it directly via FSK as with the rest of the system. It’s been inactive since at least 2014. The 15V2T in that system is still active.
They don't need to replaced the siren to get it to activate with the county's system. Granted the chargers are still good, they could equip it with a FC like they did with the other Sentrys and give it a fresh set of batteries. The FC is capable of controlling 72 VDC sirens. It's been seen before with a few Sentrys in a system somewhere in Missouri and Romeoville's old PN-20. I remember seeing one online driving a T-135ACDC at one point too. Hopefully if they do replace it the siren can be saved from the scrapper. Considering that they were willing to install FC's on the other Sentrys I don't see why they wouldn't give it a try if they knew that it was doable.

Re: Scored A Sentry SS3/Defender

Posted: Wed Oct 24, 2018 6:06 am
by Model L
what is the difference between a directional chopper and a non directional chopper?

Re: Scored A Sentry SS3/Defender

Posted: Wed Oct 24, 2018 4:42 pm
by Chem_Boffin_6589
Directional choppers can only go in one direction to make the most sound. It's when the vanes for the ports are directly at one end, like on an ACA rotor. Federal Signal rotors are non-directional, as the vanes are in between two ports. Any German, British or any euro siren will have a directional rotor to mazimise sound output. ACA used knife edges on their stators to increase even more output.

Re: Scored A Sentry SS3/Defender

Posted: Thu Oct 25, 2018 2:40 pm
by FahmiRBLX
Chem_Boffin_6589 wrote:
Wed Oct 24, 2018 4:42 pm
Directional choppers can only go in one direction to make the most sound. It's when the vanes for the ports are directly at one end, like on an ACA rotor. Federal Signal rotors are non-directional, as the vanes are in between two ports. Any German, British or any euro siren will have a directional rotor to mazimise sound output. ACA used knife edges on their stators to increase even more output.
Which means the 'blades' (Vanes?) on a directional spans directly from the axle to the chopper holes, while non-directional has vanes forming like the one on centrifugal fans?

Re: Scored A Sentry SS3/Defender

Posted: Thu Oct 25, 2018 5:20 pm
by Chem_Boffin_6589
FahmiRBLX wrote:
Thu Oct 25, 2018 2:40 pm
Chem_Boffin_6589 wrote:
Wed Oct 24, 2018 4:42 pm
Directional choppers can only go in one direction to make the most sound. It's when the vanes for the ports are directly at one end, like on an ACA rotor. Federal Signal rotors are non-directional, as the vanes are in between two ports. Any German, British or any euro siren will have a directional rotor to mazimise sound output. ACA used knife edges on their stators to increase even more output.
Which means the 'blades' (Vanes?) on a directional spans directly from the axle to the chopper holes, while non-directional has vanes forming like the one on centrifugal fans?
Simplest way for me to explain is to find a picture of a single tone ACA P-15 chopper and then compare it with a chopper from a Model 5.

Re: Scored A Sentry SS3/Defender

Posted: Fri Oct 26, 2018 3:26 am
by Snowcube
Here ya go.
Image
Image

Re: Scored A Sentry SS3/Defender

Posted: Fri Oct 26, 2018 11:27 am
by Chem_Boffin_6589
Zarlog wrote:
Fri Oct 26, 2018 3:26 am
Here ya go.
Perfect. Thank you sir.