Problem with Siren Unit

chief3 · Post by **chief3** » Wed Dec 14, 2005 9:36 am

We have a Fed Sig PA300 in one of our duty trucks. When the siren is turned on (power on, in manual mode), and you key the mic on the mobile (Motorola CDM1250) the siren activates itself.

From what the guys on shift have been telling me, this has been a problem for a couple years and the installation shop says it is in the siren box not the installation job.

Can someone help me out here. We would like to get this fixed.

mottyk · Post by **mottyk** » Wed Dec 14, 2005 8:18 pm

Sounds like a ground feedback issue

. Make sure all your grounds are good. I had a similar problem, keying to radio would activste my ss2000. After fixing the ground on the antenna the problem was resolved. Good luck.

mottyk

Jim202 · Post by **Jim202** » Thu Dec 15, 2005 4:36 am

I have seen this happen due to RF from the transmitter getting into the siren. Try moving some of the cables around

Jim

Glen W Christen · Post by **Glen W Christen** » Mon Dec 19, 2005 12:14 pm

You might also try by-passing all of the wires to ground with a small capacitor, such as a .01 uF. This used to fix many problems with high-power, low-band units when they were popular.

SafetyLighting · Post by **SafetyLighting** » Fri Mar 03, 2006 10:06 am

I just sold two sirens to a customer that is having that identical problem with the PA300. Federal Signal didn't have any ideas to fix the problem, according to my customer. For the amount of money that people pay for the PA300, much better sirens can be bought.