Not sure if this should be in the vintage section or not..

How do I treat a trigger-start 1 lamp ballast? As a rapid-start? Or I should wire it as a pre-heat?
Should I be asking instead what type of lamp should I install? Thanks.

It is all printed on the ballast. What is the question ?

The label doesn't say the types of lamps. It won't light up an RS lamp unless I brush the lamp with my hand. So is "trigger" type like a pre-heat? I know very little about fluorescent lighting circuits.

Its to be wired exactly as in the drawing on the ballast

Is the lamp near an Earthed reflector as recommended ? Is the lamp a hard starting one (try a different lamp ?)

Then I think the ballast is trash. Same behavior on all the lamps..tries to light them, glowing a bit... fully lighting the lamps as I touch or stroke them.

George, try running a thin wire like 24 AWG or even smaller, you can use real thin stuff like 40 AWG if you have it handy and you can only see it up close. Run this wire down the entire tube from cathode to cathode, just tape the ends and connect it to ground and see if this helps, I do this for lamps that run outside that don't have proper grounding within a 1/2 inch, they don't all like starting cold, if it works just put a dot of epoxy/jb weld on the wire as the UV will kill the tape in short order, or if you have a stained glass store they have nice thin copper tape for a few bucks a roll and just tape it to the back side of the lamp, it seems to last a few years so long as the wind doesn't catch it and peel it off..

Let me know if it works for you. Otherwise that ballast looks like its in good shape and hasn't been run hot so it should be fine, there is not much to fail in them and robertson seem to made pretty decent products..

I had a ballast acting like yours, and the solution was to make better contact with the reflector and lower the humidity.

What Lodge said. If it's not within 1/2" of a grounded reflector, run a grounded wire along the lamp. I always wrap the wire around the lamp instead of taping it.

Also, trigger start is like rapid start for preheat lamps. That means the cathode heating voltage is around 9V, but otherwise it works like RS.

If it's close to the reflector stick a star washer under the screw so it makes better contact and a better ground, and consider sanding the paint / enamel off the reflector where the strew sits.. And if it's going anywhere damp a little dot of clear silicon grease goes a long way to stop any rust forming and makes removing the screws so much simpler later in life, and I've also seen fixtures with a ground wire directly screwed to the reflector so eliminate grounding issues caused but just hoping the screw is good enough..

Nicksfans, If I have a thin enough wire like 40 AWG I will spiral it around the tube and I have conductive epoxy and I glue it to the metal base and simply ground the base with a spring wrapped over the base and threaded though a hole in the fixture, I like this because removal and installation is easy and if anything happens the spring will hold the tube in place, and old BIC lighter are a good source of springs just stretch them out and twist them together..