atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Security, Alarms and Paging Valcom Paging Horn Problem

Hello Everyone,
So, I have a valcom v-1030c that was working fine before I moved it. The volume is set to the proper level (very low not loud at all) and now that I have moved it, it sounds like the speaker inside of it has been blown. The only change that has been made is i have it on a seperate valcom power supply. (VP-624) I attached it to the page control power supply (VP-624 as well) and it works fine on the one that is powering the page control. I have also tried this horn on a analog SLT (with no page control attached) and it works fine when you attach it to the power supply powering the page control but when you put it on the extra power supply i have it doesn't work. So I'm guessing that it is the power supply, but has any one else ever had this problem before or run into something simmilar?

Thanks,
Daniel

Check polarity.

I did still nothing.

Thanks,
Daniel

It's clear that your self-amplified horn is in good shape. A few more details should tell us which part really IS broken.

Do you have a VOM? Using one will be the easiest way to rule out a bad power supply (or improperly grounded outlet).

Also, was this horn added to an existing wire leg? If so, how many horns total are tied to this cable run and what gauge of wire is used? How far is the VP-624B from the speaker itself?

A poor or non-existant ground will affect the output of these power supplies. Use your VOM to see if the supply is putting out 24VDC (without the speaker attached). If you're not getting the required 24 volts ± 3 volts, AND the outlet is properly grounded, then the power supply is at fault. If not, plug the transformer into a different outlet and take another reading.

If you don't have a VOM, test the suspect VP-624B by plugging it into the same outlet that the "known working" page control power supply uses. If the working supply uses a screw to secure itself to the outlet, then mount the test unit in the same manner. Don't use a 3-prong to 2-prong adapter or any other variant during the test.

I bet its because it doesn't have a ground on it. let me try that. I totally overlooked that.

Thanks,
Daniel

Your speaker requires 5 VPU (Valcom Power Units) to operate properly

I just double checked the Valcom catalog. In one place it lists N/A for power units of the 624B and in another it lists 12 power units. We normally only use a 624B for talk battery, not driving horns. You mileage my vary, but it sounds like your 624B is barely limping along.

That's what it sounds like to me. The voltage is sagging because the power supply can't supply the current.

Tim, I have never heard of a lack of ground causing problems. Can't see how it could. On "wall warts" the only function of that ground pin is to help support the weight.

-Hal

I was going to say that earlier. Grounding is not your friend on paging systems.

I know it was a month ago, but it could be piched wire. I had the same problem this week and a refridgeration contractor had pinched the wire to a beam causing have of my store to go out.

I've ran into a similar problem with a Valcom V1036c. My symptom was you could KIND of hear the audio with it cranked all the way up but it was like it was just barely coming out. 15' away from the horn it was almost like a whisper.

The problem turned out to be a bad audio cable from the PBX (Server for you purists) to the jack for the horns. Took me 2-3 hours to figure out a $5 cable from radio shack had got me. Also the last time I ever bought ANYTHING from crap shack.

The way I found out was by taking a tone generator, disconnecting the horn from everything but power, turning the horn WAY down (barely on), and then just tapping the alligator clips against the audio feed for the horn. Found my problem quick! Also had a meter across the power legs to see how much voltage drop I got as I cranked the horn up.

A meter across the audio cable with both sides open showed that the line had gotten pinched somewhere and was shorting out. All I did then was test house wiring first, then my $5 cable.

BTW, that part about turning the volume down I learned the hard way. I literally had ringing and partial hearing loss after 15-watts of horn and a tone generator went off 3-feet from my face.