I think it could be the supply. I posted some interesting test results. At 15mA, it would appear to only be driving the tube at around 19-20 watts at a voltage of 13kv.
@JamieR
This LPS is the highest failure item in a K40.
The windings short (break down) or the output diodes go bad.
These tubes require substantially more than 13K to operate properly so without knowing your test setup its hard to draw any conclusions.
My guess is that your HVT is breaking down under load.
Usually these are the symptoms:
Poor optical power
Erratic current seen on the laser current meter
Snapping or arching sounds coming from the supply
With the lights out arching or corona can be observed around the HVT.
If you suspect the HVT they are not that expensive I would just replace it, tinkering with that supply is dangerous. If that is not your problem I can assure you that sooner or later you will need to replace the HVT so having a spare is a good idea anyway.
I have a 50 watt supply coming, but I’ll definitely buy a spare transformer. Thanks!
Hmm, curiously wondering how well wiring in 2 piece 60 watt transformers would work…
What do you hope to accomplish. You don’t want to overdrive your lasers it will shorten the life without much benefit.
I’m just a very curious person. I have an 800mm tube right now, but I want to see about eventually sticking in a 1200mm, and if I can convert the power supply rather than buy a new one, it would be more cost effective. I’ve had to learn how to be frugal the past few years.
New power supply fixed the problem. Going to order a spare HV transformer. I can cut through Lowe’s 1/4" primed utility ply at 6mm/s in one pass at 17ma. Original tube could do it at 4mm/s in one pass, so there is a slight improvement
@JamieR good deal. Figured that was problem
Before changing the supply, it was taking several passes. The tube is more vibrant looking now, too!
@JamieR certainly, now the tube is fully ionizing. :).