Signal loss?

[A1pyro]

I have tried to use Cat 5 shielded cable to run my lasers. I have tried wiring it this way

using twisted pair A for pin 1 and 14
using twisted pair B for pin 2 and 15
using twisted pair C for pin 5 and 6
using twisted pair D for pin 7 and 25
link 4 with 17 on the projector-side , female plug.
link 18,19,20 and 25 on the projector-side , female plug.

And the patterns and graphics were squiggly and not normal.

then tried using 2 Cat 5 shielded cables and wired it this way BELOW (in bold) and And the patterns and graphics were squiggly and not normal either.

Pin Number Signal Name
1 X+
2 Y+
3 Intensity +
4 Interlock A
5 R+
6 G+
7 B+
8 User-defined signal 1+
9 User-defined signal 2+
10 User-defined signal 3+
11 User-defined signal 4+
12 Projector return signal
13 Shutter
14 X-
15 Y-
16 Intensity -
17 Interlock B
18 R-
19 G-
20 B-
21 User-defined signal 1-
22 User-defined signal 2-
23 User-defined signal 3-
24 User-defined signal 4-
25 Ground

Is the just because it's the Cat 5 cable or the way it is wired or would it just be better to use regular DB 25 cable or am I wiring it wrong?
I am using both versions of the ISHOW DAC'S and it does the same with both.

[m0f]

Don't know much about the ishow dac's, are they single ended or differential to the galvos ? Probably to narrow it down at least it may be a good idea to use db25 at least for testing purposes. What galvo's are you using ? May be worth a try disconnecting the galvo signal grounds to see if it makes a difference.

[VDX]

... which cable length is it?

For feeding HF-signals over long distances I'm sometimes soldering small serial resistors (10-20 Ohms) into the data wires for reducing spectral interferences and crossovers ...

Viktor

[A1pyro]

Hi VDX.
I am trying 125ft for cable length, but tried 6 FT cable first to do my testing.
which pins would the resistors be going on?

[A1pyro]

I guess it is not son much signal loss but patterns and graphics are distorted..

[dilbert]

If you are running from a laptop try disconnecting the mains charger and see if anything changes....

[mixedgas]

If your running single ended signals from the ISHOW DAC, that is probably the issue. You need to determine if the ISHOW Dac is a lousy single ended signal source. If it is single ended, you need to make a single ended to differential converter or find a better DAC. Differential signals allow the projector to reject noise using analog math in the hardware. My bet is your seeing 60 hz pickup. ISHOW is notoriously crap. It may never have been designed to drive the capacitance of a long cable, and internet cabling has the wrong impedance anyways. ISHOW was not designed to professional standards, by any means. Driving 100 feet of cable requires professional hardware.

Steve

[A1pyro]

Ok I got everything to work ok with my RGB laser, But trying the same cable on my green laser I can not get the laser to turn on. I can see and hear the galvo's moving when I change from pattern and graphics but no laser out put.
Anyone know why that would be??