That'll want a LONG run!

Yes about 12 hours. Also when its warm keep it horizontal dont tip it vertical you probably know anyway but just putting it out there

150 SON gear Adam?

Yes 150w SON gear & S16 starter. Ran it for about an hour & then switched it off... I done bad? Also, I've tried a Thorn SLI/H on the same setup and it won't stay lit. Any clues?

The Thorn ones with the “beehive” electrodes shouldn’t be switch started IIRC. I used a normal SOX ignitor on my Thorn one with no issues.

The beehive electrode one would be a HO lamp wouldn't it?? This one has normal cathodes anyway. It lights with an ignitor but the ignitor continues to pulse? Hmmm...

Not necessarily, my 140watt has beehive, but that’s on Thorns original SLI auto leak, however, if you try and run it on low loss ignitor gear, it does the same as you describe, the ignitor constantly fires!, and if you take the ignitor out of circuit, the lamp behaves like a fluorescent tube with no starter, ( ie just a flicker)!

If you take the ignitor off, the lamp goes out completely? Not sure what's going on, perhaps it does need leak transformer gear

best to use the following for 200w sli 90w sox choke and 55w sox choke in parallel gives aprox 1.55A and a sx74 or similar i took measurements and compared to a 200w sli ballast very similar i have lit gec and thorn 200w sucessfully using this setup

the 150w son choke is not suited to the lamp it will overun it sox and sli lamps have similar characteristics so the 90/55w in parallel is ideal

Thanks @thorncollector, I will try that setup, just need to acquire a 90w SOX ballast and suitable ignitor. I did monitor the power consumption from the mains, my meter was showing 209w IIRC when the lamp ran up to full brightness & 150w SON gear is 1.5A so it seemed okay? Could be wrong, I didn't have an ammeter in series with the lamp so I don't have any accurate readings