This seems fine now which is weird

Hmm that is odd. Does it light evenly after a while? Edit: typed at the same time as Kev

The reason for this is not well known. My theory is that its due to contamination of residual gases inside new lamps. Its impossible to pump away all the air and moisture before lamps are sealed, so it is customary to include a getter to capture the residual gases. In an FL lamp the fluo powder itself acts as a getter. However it only works while the lamp is lit. For this reason fluo lamps are lit for a minute or two in the factory on autoleak transformers with high open circuit voltage to keep them lit while the impurities escape and are gettered. If this process is not done completely, some residual gases can escape back into the lamp and make it difficult to start. Thorn tubes seem especially sensitive, particularly on new tubes that have never been run (if they were run in normal service then the gettering process would be completed). Because of this the worst thing you can do with old stock tubes is keep them undisturbed in their boxes, I am really in favour of getting them out and burn them occasionally, if not only to enjoy them then to prevent them getting difficult or even nearly impossible to strike like the other Thorn Radar Red which had a similar problem. We learn a lot from Kevs meeting having the chance to light these old stocks and see how they behave!

Agreed. Jon has the radar red with him i think hes gonna have a bash at getting it going, if we can get it going then we will bring it back to the next meet and return it to kev

Ive had this happend with my 80 watt GEC. I had hard time striking. Manage to got them to run on F96 HF instant start ballast

I managed to get this going near enough straight away. Id advise kev to go through them all and stick them on before work and pull em off when he gets in so that this doesnt happen again. If id had more time id of tested the lot of the coloureds