Hi.
I'm a member of a volunteer fire brigade. For the past 3 or 4 years we have had endless issues trying to get an intercom functioning clearly between the front cab of the truck and the "rops" (the bench seat behind the cab - outside the truck). Clear communication between all member on turning out to a job is vital.
From the cab, the driver or OIC (officer in charge) can speak freely into a goose neck mike that hangs off the ceiling, connected to an amp of some sort and wired back to the rops. In the rops there is a hand held mike with a button we press if we want to talk, and a speaker to hear the cabin when we let go of the button. As the engine revs up and down, so does the "whine" and static. To hear the crew in the cab, the volume has to be turned up so high that it doesn't allow us to hear each other in the back when they're not communicating with us. Our district maintenance officers have been unable to fix it to date.
There are countless trucks across the brigades with the same issue. Head office has said new trucks will use a digital intercom, but that doesn't help us now and our district maintenance officers don't have a fix.
I'm wondering if anyone can give me any advice on how I can test what the problem is with this setup, or if I could make a change to fix it. If not, I'd be happy to design/build an intercom from scratch run on cell batteries if that helps against the interference. All suggestions welcome.
I'm a member of a volunteer fire brigade. For the past 3 or 4 years we have had endless issues trying to get an intercom functioning clearly between the front cab of the truck and the "rops" (the bench seat behind the cab - outside the truck). Clear communication between all member on turning out to a job is vital.
From the cab, the driver or OIC (officer in charge) can speak freely into a goose neck mike that hangs off the ceiling, connected to an amp of some sort and wired back to the rops. In the rops there is a hand held mike with a button we press if we want to talk, and a speaker to hear the cabin when we let go of the button. As the engine revs up and down, so does the "whine" and static. To hear the crew in the cab, the volume has to be turned up so high that it doesn't allow us to hear each other in the back when they're not communicating with us. Our district maintenance officers have been unable to fix it to date.
There are countless trucks across the brigades with the same issue. Head office has said new trucks will use a digital intercom, but that doesn't help us now and our district maintenance officers don't have a fix.
I'm wondering if anyone can give me any advice on how I can test what the problem is with this setup, or if I could make a change to fix it. If not, I'd be happy to design/build an intercom from scratch run on cell batteries if that helps against the interference. All suggestions welcome.