Length of pigtail before pixels

[Retiredguy]

Newbie here. I bought a Kulp K8-B last Christmas and I have not played with it till just a few days ago.  I have 5 ports defined for my mega tree (4 for the tree and one for a star) and each has about 10 foot of shielded cable before it gets to a strand of pixels. When I test them, They all appear to have garbled data as I get pseudo-random colors and random timing for cycling.  Colors were off, timing off, and will light more than one pixel.  I tried to test just one pixel and I got some colors on one and some colors on the next pixel.  I tried a 1 foot non-shielded cable  and everything worked fine.  This would appear to be a noise problem, but I thought shielded cable would help with that. 

So what is the max length of a pigtail?  I don't know how to get signal up to the star if I can't have a 10 foot pigtail.  Am I missing something? These shielded cables were running fine with WLED and some ESP32 controllers.

[k6ccc]

Noise is not the issue, data pulse degradation is the issue.  The length depends a lot on the pixels involved and the controller.  Don't bother with shielded cable.  The solution is to regenerate the data signal.  Two ways to do that.  One is to insert one pixel about midway between the signal source and the first pixel intended to be lit.  That pixel will be called a "Null Pixel" and you tell the controller that there is a null pixel.  The other solution is a "F-Amp" which is a little board that does the same job, but works with any pixel technology and does not count as a pixel so you do not need to tell the controller that there is a null pixel.  Below is a link to the F-Amp.  the link I gave is for wire pigtails, but they are also available with several different connector standards.

https://pixelcontroller.com/store/accessories/53-famp.html

[Poporacer]

about 10 foot of shielded cable

Can you elaborate on this shielded cable? What size wire? 

This would appear to be a noise problem

Or a voltage drop problem or a ground lift problem or a connection problem.

So what is the max length of a pigtail?

That is like asking how much will dinner cost? Too many unknown variables there, but 10 feet is easily and commonly achieved successfully (typically much farther.) I have several props that are 30 feet from the controller.

[Todd]

I have several that are 25' with no issues.


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[LedMutt]

Same here, I have some runs of around 20', any runs longer than 15' I use a F-amp just before the first pixel, have no issues so far...

[JonD]

I have several 12v Ray Wu extension cables that exceed 50+ft (no f-amps or power injection needed).  Usually running small models such as tune to signs or tree wraps under 170 pixels.  No issues and f-tester agrees, but using high quality 18awg cable.  I would in no shape recommend this, but you can push the limits on occasion if you are careful.