Starting argon with external high voltage

[Cyparagon]

In addition to my two working argons, I procured a third a year or so back that just never cut the mustard. it's a 70mW Single line uniphase. The cathode heats, the starter pulses, but no emission. It looks new with little to no hours but was made last century some time.

Would it be advisable to attempt ignition with a HeNe or CO[sub]2[/sub] PSU?

 

[heruursciences]

A small spark coil to the anode will do the trick if it's not too far gone...

 

[Hemlock_Mike]

It's like a camera flash -- It needs a KITB to light up. That's what the high voltage spike does. If it won't make a plasma, there may be one last trick to get it going.
The worst thing for an Argon is to ignore it.

Mike

 

[Event_Horizon]

You say it pulses but produces no emission. Is it creating a plasma? Your mirrors might just be out of whack.

If not, then sams faq mentions just letting it sit and try to start for a while. But it has very few hours and is old, then chances are it's overpressured.

 

[GooeyGus]

I know in Sam's faq there's also a section on how to make your own 'high voltage' wand type deal to 'jump start' the laser by putting it on the anode, if the tube pressure is too high to start on its own.

 

[Cyparagon]

I'm fairly certain it's not an alignment issue. The question was if the HV from a PSU was sufficient and/or if it will damage any components.

 

[heruursciences]

Neon sign shops sell a tool called an oudin coil that can be used to test or start argon laser tubes. Alternately you can find them sold as "violet ray machines" for cheaper. If you get the older units you should probably replace the paper capacitor in it with a ceramic or mylar capacitor. The price range will be about 30 to 175 for an oudin coil depending on where you shop.

 

[Hemlock_Mike]

Again -- Does the tube light at all inside when sparked? Also measure current draw on the 120 VAC line. If over about 4 amps, It may be trying.

Mike

 

[Cyparagon]

It does not light. there is a very dim flash of blue for a split second pulsing at 1hz or so.

 

[heruursciences]

Get yourself an oudin coil

 

[MarioMaster]

It does not light. there is a very dim flash of blue for a split second pulsing at 1hz or so.

that would be your igniter circuit sending the HV pulses to try and start the tube - when I had my argon these flashes were fairly bright and the tube lased with each pulse - if yours does not that may be a bad sign

 

[Cyparagon]

Since no one answered my question, I tried it anyway and it's a no go. If 30kV can't start it, I don't think anything can.

 

[MarioMaster]

i figured, usually the igniter pulse has enough energy to make the tube lase

 

[Tallaxo]

Get yourself an oudin coil

Correct. You may be able to jump start the tube using an external Oudin coil. If you can manage this, then leave the tube running for as long as you can to lower the pressure.

Jase