I've since cleaned the centre R47, it was dusty On a side note, I discovered that the replacement ballast in the 200 watt R47 is actually 250 watts, meaning I only have one 200 watt cobra head - my M250R2
Switch 'em. The R47 has a tag, so if you want to keep that tage accurate, switch the ballasts. And don't feel bad, I only have 2 cobraheads, neither of which are 200w HPS. Well, one's NOS mercury vapor and the other is my 50's refurbished 150/175w MH/MV OV25. My OV25 was origionally 400w MV, but I wanted a lower wattage and I wanted to run MH or MV lamps for flexabilty between lamps. It didn't come with the ballast anyways.
Oops, I read "I've noticed that your R47s have the tag in a different LOCATION than mine." by accident. It is strange though that they out them on upside down.