atcomsystems.ca/forum Forums General General Telephone & Systems Information Valcom Speaker

Not sure if anyone can help me, but here goes....I am currently troubleshooting a valcom speaker system that is used only for background music, no connections to the phone system. The problem is there is an intermittent buzzing noise that will come across the speakers for 5 to 10 seconds. I can disconnect tip and ring from the V2000 control unit, only have power going to the speakers, and the buzzing can still occur. I changed power supplies, but that did not help. I have disconnected all the speakers, added them a section at a time until all spaekers were hooked up, had no buzzing during this "test period" and no buzzing for ten days. Yesterday the problem returned. Went through the same disconnect and reconnect routine today, thought I had it isolated to one area. Disconnected that one area and the buzzing showed up just when I thought I had narrowed it down. Has anyone had any experience with a problem like this? Any ideas? It seems something outside of the speaker system is inducing noise.

Are you using one power supply for all speakers?
I would look at your power source and see if there isn't some piece of equipment on the same circuit coming on when the noise starts. I don't know what kind of business your working in, but if you could start turning off breakers when the noise starts, that might point to where the inductance is originating.
Mark

welder, electrical fence, light ballast. Check whats on the ac circuit going to power supply.

Start noticing what is on when the noise occurs.
eliminate one at time.

What source is providing the music ?

It is a doctor's office. Two power supplies. Music provided by a radio, but the radio can be shut off and the noise still occurs. I suspected a ballast in the fluorescent lights. I have turned many of the lights off and on in an attempt to recreate the noise but no luck so far. Like searching for a needle in a haystack! Also several refrigerators but they don't seem to be the source.

x-ray unit ? and the list goes on and on.
Do they have a fish aquarium ?

Heat tape under bldg.

Bad wiper on sw. bank. (lol)

How about bad bond on cable tv unit ?
How about the outlet you are using or sharing ?

Well since you said you have it in sections; when it returns again disconnect/reconnect one section at a time until it goes away.

Could there be mice or rats that have tasted/chewed the wiring somewhere causing a ground short when it's moved? Seems unlikely but I've see it happen, after weeks of trouble shooting.

Could the power supply be causing it, because of the circuit it's on? Have you tried running a good ground to the common ground of the PS?


Could it be the radio putting out the hum?

are all the olm settings on the speakers the same...

what kind of cable r u using...

What sort of buzz is it a low freq. like 60hz then you have a ground loop or short. A light dimmer may cause the sound to change, if theres ticking with the buzz then it maybe a ac motor. also listen for a click at start or stop of noise caused by contact closure like the old photo copiers. Another thing you can try is resistive load across the audio line to the speakers to see if noise stops

Buzzing noise for 5 to 10 seconds has to be the x-ray equipment.