Fire dept alerting system help!

[myz32300ztt]

Hey everyone, thanks in advance here! I'm new to the forum and commercial radio work in general, but have been in the a/v space for 15 years.

Short story: My local fire dept is unable to get anyone to work on their PA/Alerting system, albeit I don't have much experience, I'm the only one to actually give them the time of day, and lets be honest sometimes these issues can be fun!


I have been doing research but unable to find what i'm looking for, but they've got a CDM-1250 connected to a 11 pin timer relay which triggers the lights, door openers, and PA system for X minutes to play through the building. The issue was the 70v Bogen amp died and the audio/pa system stopped. I've replaced that with a JBL CSMA and now we have audio and PA microphone, but no alerts. Since the new amp was a direct replacement (wires all connected the same) I somewhat expected the alerts to start coming through.

After some investigation, there's a wire coming from the timer relay to the amp thats not connected (wasn't before i got there) and there's no indicators on the old amp where it went. They used the drain as a negative and white as positive off of a relayed port on the Macromatic TimeRanger. (see attached photos, loose wire at amp is bare wire at port 10 and white wire from port 11).

My question here does anyone have experience with this type of setup? It seems to me there's no feed from the relay to the amp for it to send the signal through. I'm thinking the wire above is the culprit, however I've got no experience with timer relays. Should that wire feed the signal to the amp, is it a trigger for the amp and it gets signal some other way?

Thanks again in advance. I can provide any more color to this if necessary.

 

[kb4mdz]

First things first, what DOES work? Does the radio alert? & Trip the relay?
And it will help if you diagram the pinout of the CDM1250 accessory plug; I can remember that Pin 7 is always ground, and audio comes out of ... often # 11; Flat or Filtered audio (pre-volume control, and also with no alert tones injected into it, i think).

#4 is the triggered output, High or low (+V or Ground), depending on programming

I can't tell from the pictures, but it looks like a white wire, going to PIn 6, which is not a functional pin, anyway. Confused...

Oh, and just check that all the pins are in the accessory connector well; if you look at the radio side of the connector can you verify that all pins are seated down properly so they will make contact?

Here's what I used when I was doing them locally:

Fire Station Alerting System

We use a 2-tone paging system to notify personnel of an emergency. We have a receiver/decoder tied into the stations PA system. For many many years we have been using a Federal Signal Station Informer to decode the tone for the station. This device recently started to fail and we don't have...

forums.radioreference.com

 

[myz32300ztt]

kb4mdz - thanks! in response:

What DOES work from radio, alerts come through because lights are triggering through timer relay as well as i can feel the relay fire. This tells me part of the relay is functional. I plan on pinning out the radio and labeling everything this evening as well as ensuring proper connections through out as well as testing the relay.

the #6 pin wire connects to the relay in the bottom left of the image. but yes also confused especially if the pin isn't functional on the relay.

Appreciate the image! Lets hope i can make some progress tonight. I'm wondering if there's a correlation between pin #11 on radio harness to pin 11 on the relay, i've seen weirder anomalies.

I'll hopefully get some more detail this evening.

 

[TampaTyron]

Seems like a non-virgin failure (i.e. someone was in there before you). Interested in hearing what you find this evening. I am betting someone probably mucked stuff up, so you may want to approach this with zero trust in the wiring or programming. TT

 

[mmckenna]

So, not audio alert tone over the PA system?

The alert tone comes from the radio via the audio output via Pin 11 (flat audio output), or as KB4MDZ said, it might not, and you'd need to pull audio off the speaker output, but I think we used pin 11 on ours.

We had our radios set up so that there was a few channels programmed the same, but with different audio functions. "Day" mode just sent audio and the 2 tone page signal out over the PA system. "Night" mode did the alert over the PA, plus triggered station lights. If one of the FF's changed the channel, that could be an issue -if- the radio was programmed that way.

 

[Firebuff880]

Be sure you read the read code plug, as some pin assignments are done in the software...

 

[hitechRadio]

My Guess is that the white wire on pin 6 should go to pin 8. If the white wire is in fact audio from the radio.

The radio will not activate the relay until AFTER the tones are decoded.

After looking again, where does that red wire go hooked to pin9?

 

[cmdrwill]

audio output via Pin 11 (flat audio output),

No Pin 11 should be filtered squelched audio and this IS low level. Then that goes into the PA amp aux input. The relay should have a contact to switch off the audio from the radio going to the PA amp when not alerted. You may need a isolation transformer, aka hum eliminator in the audio path.

 

[myz32300ztt]

Everyone, thanks for all the help! I just left the station and we did get it working.

TampaTyron - Your 100% on the nose, someone mucked it up. Since it did work then didn't i started with not trusting wires first.

kb4mdz - Did the pin out found pin #4 is alert out (was working fine as expected since lights also were triggered), pin #16 (speaker +) was connected at one point but not currently, and pin #11 which was the audio line out.

After pin out found that the pin #9 (cmdrwill) was coming from the line audio from radio. Which the image from kb4mdz, showed the relay jumps 9-11, so my mystery wire was the issue! I had the 911 center send a test while i checked for voltage and sure enough, we had signal. I connected it up to amp, and just like that it worked!

Thanks every one for all your help! Appreciate it!

 

[kb4mdz]

Congratulations!!