M1 weird siren static

[kwschumm]

The M1 siren works fine. It is set to voltage only, connected to OUT2, and it wails like a banshee during alarm conditions. What it also does is produce a steady stream of staticy white noise whenever a keypad chime function issues a voice announcement. There is no static when the siren is disconnected, and the noise is only present for the duration of the voice announcement.

Ideas?

 

[RAL]

I'm not sure of the cause of your static, but it might be caused by the supervisory voltage on OUT2 that is used to detect a cut wire.

Here's an old thread on that topic (with a link to another old thread) that suggests placing a resistor (can be as low as 100 ohms) across the siren as a way to fix it.
 
http://cocoontech.com/forums/topic/24967-elk-45-siren-making-suming-sound-when-on-stand-by/

 

[kwschumm]

Thank you RAL, a 2.2k resistor in the siren did the trick. Thanks for sharing your expertise!

 

[RAL]

Thank you RAL, a 2.2k resistor in the siren did the trick. Thanks for sharing your expertise!

I'm glad it worked!