hi, I recently put together a diy 150w ballast (not multi-tap, rather 120v tap only) and have what i think is an issue with ballast making a vibrating noise. This only happens when the unit is first turned on and lasts only until the bulb is full intensity. Once the bulb reaches "plane" all's quiet. I'm thinking this is caused by one of two reasons. I hope to get your opinion from diy ballast builders. 1. My band-iron strapping i used in my ballast box to hold the transformer down is not tight enough or i need some sort if heat retardant insulator between the straps and the coil to take up the vibration. 2. the specs for this ballast lists the bulb only being a max of 3 ft away from ballast. Currently i'm sitting at around 6-8ft distance between ballast and bulb. Maybe pulling too much current due to voltage drop from the longer then spec bulb to ballast distance. comments? thanks
Thanks for the reply. I guess it wouldn't hurt to keep things to spec with regards to bulb to balence distance which for my ballast says 3ft. I read that if not using a long distance ignitor you run the risk of damaging the ballast/ignitor. I'll see if I can cut the distance down to even 4ft from the current 8' I have approx now.