I have recently found a 4000K CMH lamp to install in this lamp. It is a Philips CMH of 50 watts, made in China in 2015. The ballast is a Universal electronic MH. I seem to notice a very slight but noticeable flicker when it is running. I'll have to put in the old lamp back to see if it flickered as well. I am thinking it may be impurities in the arc tube that need to burn off before stabilizing. Any thoughts ?

I have recently found a 4000K CMH lamp to install in this lamp. It is a Philips CMH of 50 watts, made in China in 2015. The ballast is a Universal electronic MH. I seem to notice a very slight but noticeable flicker when it is running. I'll have to put in the old lamp back to see if it flickered as well. I am thinking it may be impurities in the arc tube that need to burn off before stabilizing. Any thoughts ?

Has the lamp ever been used before? If so, it's a new lamp therefore it needs a burn in period to stop this. My philips 250w PSMH did the same thing for a few hours before it had a burn in period.

Yes, the lamp is new. That's what I thought about the burn in period.

Yeah, I think halides need a period of maybe 100 hours to fully chemically stabilize.