How to connect Power Supply to Meter and Tube

[wrench]

I am almost complete with my wiring but need to know how to connect the current meter/laser tube and power supply together.
The smaller red wire that I show is a wire I had labeled as going to the old analogue meter and figure it must go where it is shown in the drawing.
Can someone show how I connect the terminals I have labeled as 1,2,3...and a,b,c.. together. Or point me to where I can read how this is done.

[wrench]

Do I even need this meter? I don't see any of the laser machines posted even showing one being installed.
The small red wire is spliced onto a green wire ( but all the wire colors are mixed on this laser) and I am pretty sure
this is the negative for the tube. So, what I'm thinking is to just join the small red wire directly to the Cathode end of the tube.
Heck, what could go wrong?

[waltfl]

Hi there
you need a mA meter to control the power because you should never go over 18mA,
but you could use the original analog meter what comes with the K40 machines and there you only connect ein pol with the small wire from the PSU and the other pol with the cathode wire.
greetings
waltfl

Do I even need this meter? I don't see any of the laser machines posted even showing one being installed.
The small red wire is spliced onto a green wire ( but all the wire colors are mixed on this laser) and I am pretty sure
this is the negative for the tube. So, what I'm thinking is to just join the small red wire directly to the Cathode end of the tube.
Heck, what could go wrong?

[wrench]

Thanks, but now I can't even find where the old analog meter is...

I think I am about ready to pack this up and return it.

[JAV-1]

I put a simple analog meter inline of mine. The digital meter was causing too many issues for me.

[wrench]

Thanks, I found the Meter and connected it along with the Big Green Resistor and now I can test the Laser.
I'm sure I'll have more questions at that point.