Any tips on bringing my reliant 250M back to life?

[GooeyGus]

So I got this reliant 250M in the mail today. The power supply is totally hosed... there's a huge hole in one of the capacitors and the guy said he's pretty sure some if not all of the fets are fried.

Anyway, I have a JDSU power supply as well as the umbilical/igniter from a dead JDSU tube that I have. I hooked everything up and tried to fire the tube, about half the time the starter pulse goes through the tube and the other half it jumps the spark-gap on the igniter board. When it pulses through the tube I get a flash of plasma light (no lasing) but it wont sustain.

I really have no idea on how the reliants are normally wired so it could be that I need to position the igniter somewhere else, or I could be totally missing something... Right now it is hooked to the cathode like on the JDSU tubes. Here are some pictures of how it is wired up:







Should that be ok?

Assuming the wiring is good to go, how can I help this tube out? It was fired up and confirmed to be good one year ago, but has been sitting ever since. I dont have an oudin coil, but I do have a couple HeNe power supplies. Can I use the HeNe PSU in any way to help this thing fire?

All that is currently hooked to the tube is the yellow wires (three of them, they all go to the cathode, one of them comes from the igniter board), the blue wires (two of them, other side of cathode), the black wire (anode), and the two orange wires are connected to each other to satisfy the interlock in the PSU.

Thanks in advance for the tips!!

~Jason

[mixedgas]

JDSU is a 90V tube, reliant is much higher, the jdsu ignitor is puny. Might not be enough start V across the tube. Dont try to measure it.Almost always on a fet bucking supply one lytic cap (the output filter side of the buck inductor) blows and the fets and fast diode blows. Play the lottery and replace the lytic and the fets.

Steve

[mixedgas]

JDSU is a 90V tube, reliant is much higher, the jdsu ignitor is puny. Might not be enough DC start V across the tube. Dont try to measure it.Almost always on a fet bucking supply one lytic cap (the output filter side of the buck inductor) blows and the fets blow. Play the lottery and replace the lytic and the fets and fast diode.

Steve

[GooeyGus]

JDSU is a 90V tube, reliant is much higher, the jdsu ignitor is puny. Might not be enough DC start V across the tube. Dont try to measure it.Almost always on a fet bucking supply one lytic cap (the output filter side of the buck inductor) blows and the fets blow. Play the lottery and replace the lytic and the fets and fast diode.

Steve

Alrighty, I'll buy all new fets and rectifiers and caps and see what I can do.

The only other supply I could try this on would be my cyonics supply... but I have a feeling it would just be similar to the JDSU supply. I guess I could try the HGM5 supply (joking )

Shucks... I really wanted to see if I could get this thing lasing tonight.

Tomorrow I have a crate coming in with a spectra physics 164, an s/p 165, and a 265 PSU. SO once I get those I'll probably be busy for a few weeks tinkering to even work on this one. I'll add this to all the other projects on the burner... I think I'm going to need a bigger stove.

[mixedgas]

since the inevitable next question is where do I get a 265/164/165 schematic and manual.

The answer is it costs about 20$ to c opy and 4-5$ to mail

Steve

[GooeyGus]

since the inevitable next question is where do I get a 265/164/165 schematic and manual.

The answer is it costs about 20$ to c opy and 4-5$ to mail

Steve

I'll be sure to get a hold of you soon to get that.

Also, you wouldn't happen to know anyone with a wiring diagram for the 250M would you? This thing is totally disconnected from everything/half disassembled so it's going to be a challenge to figure out where everything connects to. The guy removed two of the fets (or maybe a fet and a diode... I didn't look close enugh) and I believe he included replacements for them, but there's still a few areas which seem to be missing components or at least connectors. Pics are uploading right now

[GooeyGus]

Here's what I'm working with electronics-wise with the 250M:






















Before I dive in to giving this thing a proper overhaul, is there anyone here who would be willing to test this tube for me on a reliant PSU? I want to make sure the tube still lases before I go spending money on this PSU.

[mixedgas]

I can test it, on a reliant psu.

Steve

[DZ]

Hey Jason, I can also offer testing of the tube if you like. I've just finished fixing up this 250M here. Also, I just tested the tube voltage. Prior to discharge, the tube voltage is 332VDC. While running at low current the tube voltage I measured is 97.1VDC

[mixedgas]

I've got a similar board, do you have medical one (curestar?) or science one?

Steve