Helium-Cadmium laser heads, need directions about heating sequence and temperatures

Hi everyone,

In a short time (about two weeks) I'll have the opportunity to acquire some Helium-Cadmium laser heads with no power supply

I have read what is about them on sams laser faq, but I still think I have more information to gather in order not to ruin the tubes life by building my own power supply

The tubes in question should be some liconix 4420 tubes (long ones), and I'm looking for some information about the power supplies existing for those

I would be glad to see some schematics of liconix power supplies if someone have them (with a non-disclosive agreement if needed of course) in order to have decent information about the thermal/pressure control loop of the cadmium reservoir (as sam gives those informations for omni tubes and liconix are different models)

I really don't want to see a bad cataphoresis taking place and ruining my cathodes/optics

I'm basically thinking about Steve on that one, as he may know these tubes and their anatomy, and any help would be welcome from others too :)

When I get them, I'll provide the common dose of pictures :)

Thank you all for your help!

Some time this weekend I'll get to you. Then in a week or two when I get home I'll scan the hecad tuning manual for you. I hope you like 3KV and say 50-60 mA PSUS.
The post in SAM's FAQ about tuning and watching that yellow line is SPOT ON. (pun intended)

Steve

Thanks Steve,

I read sams notes about omni tubes, and that's why I decided to ask in your direction :)

I have a neon sign transformer rated at 7kV 75mA, a 900V 100mA transformer, 500mA and 2A variacs, HV caps, HV diodes, small logic and analog usual ICs (made a provision of 555s and 339s on that purpose), and everything needed to design a current source for several kilovolts (I'm even tempted to make those out of valves like EL36 and the like :))

All I have to find now is how different a liconix is from an omni, in order not to coat the inner optics with cadmium or eat tree quarters of it's life at the first running test