Got my BD-10A today... (hand held tesla/oudin coil)

[GooeyGus]

I had the tube hooked up to the PSU when I got it to sustain, so once I pulled away the BD-10A, the tube was maintaining an arc by itself, probably at 10A tube current (because the PSU was still trying to start it... not sure why... probably because the light sensor was disconnected so it didn't know when it struck?)

Hope that helps clear the confusion... I think pat was thinking that I was just zapping the tube without it having power running to it, just to check for gas

[Laserman532]

I had the tube hooked up to the PSU when I got it to sustain, so once I pulled away the BD-10A, the tube was maintaining an arc by itself, probably at 10A tube current (because the PSU was still trying to start it... not sure why... probably because the light sensor was disconnected so it didn't know when it struck?)

Hope that helps clear the confusion... I think pat was thinking that I was just zapping the tube without it having power running to it, just to check for gas

Ahhhh yes the lacking information supplied on threads- gooey sounds like your start pulse is weak or too short. It sounds like if it is still striking after current draw there is an electronic sensing thingy wrong, the photo sensors usually would not be in that loop. Photo sensors are used for light feedback stabilization of current for constant light output (light mode) I have not heard of a sensor that picked up laser glow but laser light yes.

[GooeyGus]

Ahhhh yes the lacking information supplied on threads- gooey sounds like your start pulse is weak or too short. It sounds like if it is still striking after current draw there is an electronic sensing thingy wrong, the photo sensors usually would not be in that loop. Photo sensors are used for light feedback stabilization of current for constant light output (light mode) I have not heard of a sensor that picked up laser glow but laser light yes.

There could be something wrong with the ignition circuit... but I'm pretty sure this tube is dead regardless. I really had to shock the crap out of it to get the arc to maintain. The 'usage' meter is completely off the scale, I think this was one of those semiconductor inspection lasers and they pulled it from service when it died (KLA Tencor). I just wanted to see if it would lase if the arc maintained... it didn't, but I'm going to run it for a while after I get it started again just to see what happens. When I got the tube to maintain, I was just working with the bare tube by itself so I had to shut it down quickly after it started. I'll mount it back in it's tube and see what happens when it runs for a while with proper cooling and all that good stuff.

As a side note, could the starter's failure to cease sparking have to do with the fact that the starter board wasn't electrically connected to the tube other than the wires going to the anode and filament? There are a few more wires (light sensor board and two ground wires (which I assumed were for the board as well, i'll look at my assembled tube to see how they were connected)) that weren't connected. I was thinking maybe if it didn't sense voltage across the tube, due to these wires not being connected, it would keep firing.

[mixedgas]

for a air cooled, that sounds like high pressure tube that needs ran.

Put it back togther, lead a well insulated wire out the head with a air gap to the fins from the wire. Gently spark the wire with the BD-10. This takes some experimentation to set up if its a round head, Start the tube gently using the tesla and let it run off the psu at medium current for hours if not a day once it starts.

It will go one of three ways, you have a old tube with poor cathode emission or low pressure, and it will continue to be a nonstarter. It will be a high pressure tube that will clean up. or It will be a weak ignitor/psu fault.

With the light feedback sensor off, it should surge to max current limit.

Steve