315w cmh problem

my bulbs make a high pitched khz one tone sound(eeee) constantly it's giving me a headache is their something wrong with these bulbs using mogul 4200k bulb phillips ballast i've checked all the connection and changed the ballast over to another one but they continue to do it

Magnetic ballast?

electronic ballast and it's the bulb thats making the noise

315w cmh phillips advance ballast

How old is the bulb? Are you using a dimmer? And why are you using 4800K lights?

4200k and the bulbs are brand 'new' and 'no' dimmer is connected

It's harmonics but I have no idea why if they are in the proper position. Bulbs are sometimes designed to run only horizontally or vertically. With musical instruments it's usually related to 60-cycle interference.

bulbs is universal and it's 50hz cycle in aus

Here's one explanation I found:

"
The audio noise is probably the frequency or a harmonic or subharmonic of the DC/AC converter that drives it.

Flourescent tubes have to run off alternating current to balance the wear on their electrodes they also need quite a high voltage to get them going. If you want to get an alternating current from a battery you have to run some sort of oscilator from the DC power source and transform its output to the required voltage to run the gas disharge in the tube. It is more efficient if these run at frequencies higher than the normal 50Hz mains so they often use audio, ultrasonic or even radio frequencies. The most likely source of the sound is magnetostriction in the coil that forms a major part of the oscillator although the discharge in the tube can also make a noise."

From the Naked Scientist.

the system runs at 110hz also woudn't a harmonic damage (resonance) the bulb

do u have a second bulb to try? Phillips has good CS, shot them an e-mail. Let us know what they say.

Mine does it too...

I have the 4200k Philips bulb, mogul base.

Mine seems worse in horizontal orientation. I've been running the bulb for nearly a year now straight, so no detriment that I can see...

I just tap my hood,and the buzz go's away..