Argon Ticking

You could repair yours for probably <$10-15, or buy a new one for $80+. Your choice..

Usually it's only a handful of parts that have shorted, or gone bad. Based on the pics you sent me, I am almost certain it's the PSU.

Though you still need to confirm. Once you can confirm it, then it's safe to start probing for shorts.

Once you fall into the habit of just junking repairable equipment at the site of an easy replacement, you will quickly discover how quickly this hobby can get expensive. Especially when it comes to repairing old gas.

Well I just found out that my fan is also probably too small for the ALC 60X... it's a Dayton shaded pole blower, model 4C006B. Sam's Laser FAQ notes 200CFM+ fans, this one looks like 120CFM...

It is likely that the tube is overheating. I don't know the behavior of an overheating tube, so I won't even try to hypothesize anything.

Anyway, hitting the rack, hope all goes well for you!

Hah! shaded pole... 120cfm in the wind maybe. Stay away from shaded pole if need anything remotely powerful.

What kind of fan should I be looking for?

My sources DO say 115CFM is the minimum, and 185CFM is recommended.

As far as what to look for? I know a couple model numbers for squirrel cage style fans, but ALC 60X heads are typically refitted with a box fan right to the head. Is yours that way?

I would use a search tools from one of the box fan sites and put in the parameters you want:

Input: 110VAC input
Output: 185CFM output
Size: Take you your pick. box or square.

I'm not familiar with fans, all I know is that my fan is a Dayton pole blower secured to the laser head by two screws. There is about 3/4 inch of styrofoam type material separating the top of the laser from the bottom of the blower.

I'm not familiar with the cfm ratings and what appears to be some kind of length/distance measurement, can someone explain this for me? Thanks

EDIT: my blower: 118 CFM @ 0.500-In. SP. Is this safe to use with my ALC? I'm not familiar with these measurements

bloompyle said:

It is likely that the tube is overheating. I don't know the behavior of an overheating tube, so I won't even try to hypothesize anything.

Anyway, hitting the rack, hope all goes well for you!

Click to expand...

The tube can't really overheat if it doesn't ignite first

Usually there's a bimetal temperature cutout switch in the head that will cut the main interlock if it overheats. This is a problem where the supply isn't producing the normal voltages required to ignite the tube or the igniter isn't functioning properly.

Since the igniter is producing flashes of light only on one end it's either too weak to ignite the whole tube or there's just no power to strike a main arc after the ignition pulse. Probably the latter.

There's been more said in pm, than in the thread.

It is igniting, and lasing 8 lines on full power, and 2 lines anywhere below 50% power.

That's good then! Glad to hear it's lasing, what ended up needing tweaking?

Just left it on for days.

I guess it gettered itself to life without blowing the cathode to pieces.

The getter is usually a one shot deal in vacuum tubes to remove O2.
I have said that I run my cathodes for several minutes before slipping
them the anode volts. That has worked for my under exercised argons
for years. Get the cathode hot like in gas filled radio tubes.
HMike

I haven't run my ML Lasos in over a month. I lit the cathode for
45 seconds, no fan, and turned on the beam. After the 15 sec delay,
instant on with 8 beams.
Great room heater plus photons!!!

What does 2 lines at idle mean about the laser tube? Is it at the end of it's life, needs to be run more, or something else?

I'm curious. at what current and light power is idle?

This 2-line thing may still be related to the PSU.

I see 6-lines at idle, roughly 6mW and 8-lines when running at 30mW and above.
I'll test what current these occur next time they're out for a run.

I haven't been able to figure out how to read the current using the red/black jacks on the laser head. I tried putting my DMM leads in there but I got a fluctuating cycle of 0.05V to 0.2V, which can't be right (0.2V/A conversion factor).

At min current from the PSU knob, I'm getting 2 lines, 3mW. At max current from the PSU knob ("over current" LED brightly lit on the laser head), I'm getting 8 lines, 86mW

With the tube in Current mode, and the pot set midway, you should see a clear and definite steady reading - especially if the light output measures steady. If not, the PSU’s ability to hold a steady current is in question. I've forgotten the actual meter readings, and how they correlate to amperage. Another member can clarify. I seem to recall it being 1V = 1A.

Have you had a chance to measure the tube operating voltage? This can help you determine tube health and life. The voltage is somewhere between 100 and 115VDC. If it’s at the upper end, high internal pressure may be indicated, and letting her run for a while (50 hour burn-in) should correct this. If it’s at the lower end (or below) then it could mean the tube is near end of life.

The current compared to the output power is another indicator. 80mW on max current is pretty common. But I have seen hot lasers and new ones produce close to 200mW at max current. Since we don’t know what the freak is wrong with your PSU, your 80mW is inconclusive.

10 amps is the maximum you want to run your laser at. So understanding how to read the current will be important.

How long has she been running? Please, tell us about the tube’s health. I think we had to hear you got it running from another source.

Have you shut her off, yet? Does she come back on, now, without a great deal of heartache?