WTB: B&W Tek 473nm

Grey ones are the thermistor if memory serves. Red and black are the TEC. Just check continuity with a multimeter from the solder blob on the TEC to the end of the cable.

ARGLaser said:

Grey ones are the thermistor if memory serves. Red and black are the TEC. Just check continuity with a multimeter from the solder blob on the TEC to the end of the cable.

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Everything is covered in heat shrink in the head. There isn't a single bit of uncovered wire in this unit..

Any tips on the beam? I vaguely remember some sort of lens mod going around when these were a "hit"?

My apologies for the thread jacking. Perhaps this should be taken to PMs?

Double post:

All continuity tests results triple 0's so it can't be the TEC's connection..I'm lost here.

The divergence on these are horrid because they were designed for use with a fibre optic coupler to be used as a fluorescence probe. You can take a short focal length lens and place it at the focal length in front of the laser to get a nice collimated beam. (I.e. if you have a 5mm fl lens put the lens 5mm after the final lens after the crystal set.)

Btw the plastic nonsense on top of the crystal set is just that; nonsense intended to diffuse the stray IR. It can be removed without any detriment to the laser's functionality.

bloompyle said:

Double post:

All continuity tests results triple 0's so it can't be the TEC's connection..I'm lost here.

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I should have been a bit clearer. By disconnected I meant physically. Some of the TEC's separate / split,
or break loose from their gule, and same with the crystal set mount. They are all glued in place and when
they lift out of position, or do not cool properly, the power does what you are stating.

Its the usual problem ive seen where the output drops off. I would first open the plastic guard and remove
it carefully. You will be able to see the crystal mount, then visually inspect for any loose or 'wiggling' parts.
Next, tap in to the -/+ red and black line to the TEC under the crystals and hook your DMM to it.

As you mentioned you do not have goggles. Do not power up the laser with the cap off and the plastic
guard out of place. Hook up your DMM, then place a piece of paper over the labby, just be sure not to knock it off.
Then power up :scared:

Another thing to try may be to run the laser for 5mins, and check the temp of the mount over the TEC. If its
high than room temp, your TEC is not functioning.

If you cant find any issue with the temp control, get yourself some IR goggles and tinker! If its an alignment
issue, you can get it, it just takes time. :beer:

bloompyle said:

How did you manage 84mW? Mine does 20mW around startup then deminishes to around 2-3mW in TEM01 in under 30sec.

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if you continue to let it run it will go back up to about 20mw - takes a few minutes tho.

I'm already getting IR goggles pretty soon, but about the paper. A simple sheet of paper will block the IR? It seems too easy...

Just ran it for about 25mins, the outer case was VERY warm, however, the optics block was quite cold to the touch, so the TEC is fine. Also, after about 10mins it began climbing in output and stayed there with a fair amount of stability. So I'm not TOO dissapointed in this unit, but I definitely want a stable >100mW 473 in the near future.

bloompyle said:

I'm already getting IR goggles pretty soon, but about the paper. A simple sheet of paper will block the IR? It seems too easy...

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Its not a direct beam you're collecting with the paper, and what little amount escapes
the cavity, its easily absorbed and reflected back off the paper.

RE: your other post, you never ran the laser for an extended period other than the
25mins you just ran it for? All DPSS need some time to stabilize. I assumed from your
post that it dims out after a few seconds meant that the power stayed there.
These laser heads need some time to come up to power.

What kind of power were you seeing after the 25min time frame?

Good to hear your TEC is in one piece. Out of 30 of these, I saw at least 10 with
issues surrounding the TEC or crystal set mount breaking loose. This is where the
power will peak, then fall and stay low.

Yours sounds to be in good shape :beer:

Looked around where it started, not all that bad, hoping I can get the beam a little better (VERY dirty)