Noise from outdoor mercury vapor light fixture

[Opcom]

It's a 175W MV lamp, typical for use on a pole or high up on the wall of a garage, etc. It has an electric eye on it.

I noticed the light was on in the day time. Upon investigating the thing, I noticed the clear cover over the eye was missing and the photocell was visible. But that should not have made it stay on. I pulled the electric eye off and took it apart. It is a twist-lok style that goes on top of the fixture and was made in 1989.

Opening it, there are no active components, just a large photocell and a snap contact with a little heating element on a bi-metallic strip. The photocell carries the current to heat the switch.

After many years the plastic lens must have come off. The photocell was all corroded and I guess it is passing enough current to keep the switch on. There is so much crud on it and evidence of current flow through the crud that I can easily imagine the noise it might make. The noise stopped when I removed the electric eye assembly. I am going to buy a new electric eye and see what happens.

It's like the picture. If others have these and they are old, might not hurt to make sure they are still well sealed and clean. I guess mine worked a long time before it finally got corroded and noisy.

[flintstone mop]

The bulb probably needs replacement too.
The power company usually replaces the entire assembly. No use trying to shot gun obvious problems like the photo eye. The entire fixture isn't a budget buster.

Fred

[w1vtp]

My noise problem stopped abruptly over my VA trip.  It would come on at dusk and go off at dawn.  I got no cooperation from the power company here nor from FCC.  I put the complaint in to FCC and it went into a black hole

I'm happy now with the noise gone

Al

[WA2SQQ]

I'd use a sling shot to fix it! Bet you they would fix it after that!

[Opcom]

This is my fixture on my garage. It is my responsibility to maintain it. The lamp is perfectly OK and does not need to be shot. Its a better MV lamp than the original clear kind. It has the phosphor coating inside  the outer envelope to give more visible light across the spectrum.