Flickering/rainbow in output (Cadet I/II/III)

Helpdesk
1

I’m trying to get rid of some artifacts in my LZX system’s output. Problem #1 looks like this:

20210425_152222
20210425_1522224032×1908 1.19 MB

The rainbow colors you see are scrolling by quickly. The patch is external media player composite output → Cadet III → Cadet VII for scaling + offset → Bridge mult → RGB inputs of Cadet II encoder. Additionally, the composite out from the Cadet III is going to the sync input of the Cadet I.

I’ve tried to isolate the issue by changing the display device. Two different LCD displays show the issue with direct composite inputs. Running it through a Blackmagic Designs Analog to SDI → SDI to HDMI (or BMI UpDownCross HD) → monitor showed the same thing. Analog to SDI Mini → BMI HyperDeck Studio Mini shows the same artifacts on its built-in screen.

I also eliminated the power brick (a no-name 12V 5A adapter) and powered my Malekko Power from a good quality bench supply. No change.

Finally, I unplugged every other module except Cadets I, II, 2X III, and a Cadet VII. Still no change.

The rig is built into a 6U rack case, and this is the test patch:

20210425_152317
20210425_1523174032×1908 1.67 MB

I’m also investigating fuzzy edges on my Cadet VIII Hard Keys.

Any ideas?

2

I had something somewhat similar when trying to get video from a Raspberry Pi to a similar Cadet system, and what did it for me was making sure I was outputting b&w video from the Pi. When I’d use color it had problems like what you described.

Not sure if it makes any sense, or if it would fix your problem, but it fixed mine.

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3

That’s interesting! I’ll see if my media player has that option.

I just tried using the HyperDeck Mini as a video source (via BMI SDI → Analog), and it was even worse!

4

How fuzzy are your cadet VIII hard key edges? I’ll try to capture some picture of the edges on mine tonight that you can compare to. I think you’ll always get a little noise on edges from electrical noise, distortion from circuitry and jitter.

5

Yeah, if by fuzzy you just mean a little jagged, then I too can report that I have found that to generally be the case with the Hard Key module.

Less so with cleaner power, but pretty much always a little.

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6

I was pretty close to starting a new thread about Hard Key edges… might be worth doing so for others to reference, if it’s a known niggle

7

A new thread for Cadet VIII issues might be a good idea, yes.

I did a little test on this yesterday: with the Malekko Power being fed by my bench power supply and only a limited number of modules powered up (added Cadet ramps and two VCOs to the above test group), I’m getting very nice clean lines on the Hard Keys.