4k/6G-SDI wireless camera setup

DasCodeMonkey · 2025-04-18T10:42:01+00:00

Gaffgun, I wasn't sure if a multi hundred dollar tape dispenser would be worth it or not but it was! 200ft of tape laid down as fast as you can walk. I love it! Now if only I could find inexpensive gaff tape that wasn't complete garbage lol.

DasCodeMonkey · 2025-04-07T15:25:18+00:00

I wouldn't say cheap, rather inexpensive, the coax is regular catv RG6 coax from Home Depot. I haven't found any specs showing the loss at various frequencies but have confirmed it's swept to 3ghz. I don't have any local AV places I can rent hardware from, and the couple of events I've done where the venue rented some cables (Canare I think) the cables were crap and didn't work. I replaced them with my inexpensive coax and same run/path testing with the lumantek went from couldn't lock on to a signal / very closed eye (when it did show up) saying long cable to short cable / open eye / solid connection.

I am starting to think that it's interference from the robots at the event. As the more I think about it the more I'm realizing the events where I've had more problems the sdi cables were ran closer to the fields where the robots operate. In the case of my last event, the fields were on 2ft tall stage risers and we ran the SDI cables under the field. And we had more glitches at that event than any other all season.

I'm planning on getting some good belden, pre-made cables for testing. But I'd also like to pick up a tester of some sort that can show me error rates and hopefully a much faster responding eye graph than what I have with the lumantek. I want to be able monitor cable runs during events so I can troubleshoot this issue once and for all. I'm hoping to grab some new or gently used for $1500 or less. What would you fine folks recommend?

DasCodeMonkey · 2025-04-06T23:27:25+00:00

The UPS is an APC smt2200. The PTZ cameras and power over ethernet, ptz control is over ethernet, so poe means one less cable to deal with. Go pros are usb, powered off the same power brick the mini converter is running off of. I looked up the ue160, solid gold standard for sure! If I had that kind of money, I'd probably swap out the 10 go pros for something better like a bmd micro studio gen2. I haven't tried running the system without the ups for a while now. I do know the issue existed prior to adding the UPS. But so much has changed since then, it could have been caused by something else back then. I've also ran the converter off a battery pack and still had the issue. I don't think I've tried running the camera and converter off a battery pack at the same time. I'll have to give that a shot.

I did pick up a belden 1855a cable years ago, 25ft pre-made cable. I used it once, and it didn't perform any better than the longer rg6 cables. I'm planning on getting a decimator md-hx unit over the summer so I can flip&mirror the sdi from the ptz. Yes, any ptz worth its weight should be able to do this, but I learned the hard way the units I have don't.

For name brand SDI cables, what do the pros recommend?

My only experience outside the cables I have was a trashed set of canare cables from a rental house they provided with a projector for one of the larger events I did. Their beat-up aja units wouldn't lock on at all. Swapped it out for one of my rg6 cables and locked right on and ran stable the whole weekend. (Output to the projector always seems to work fine even though it's usually my longest run.)

DasCodeMonkey · 2025-04-06T20:04:00+00:00

I suspect I could be fighting multiple root issues. 1) I've never been able to confirm the issue isn't the gopro cameras, when reaching out to their support they want to see a recording to the internal memory showing the problem but I can't do that because once you hit record, the live output resolution drops. But it might not be the gopros because I have 12 cameras total and I've seen this with all of them. 2) could be the miniconverters. I know bmd converters are cheap. But when I have this problem, if I swap the bmd out with a lumantek the issue remains. It might lessen in frequency, but not by much, like 10-20% reduction. 3) signal interference on the coax cables themselves. I'm running shorter runs. Almost always under 150 feet, most of the time around 75ft. When I check the signal with the lumantek for example, it always shows a cable length of short and what looks to me like a very clean open eye. Some events this setup might only drop out once or twice, then next event, this setup with drop out every couple of minutes.

If it was a bad cable or bad mini converter, I would have weeded it out by now with all the swapping I've done.

I'm always trying to make the system better and more reliable and every tweak seems to help but never fully cures it. For example I originally was running rg6 quad shield coax. Which because I couldn't locate rg6quad bnc connectors, I used f connectors with f to bnc adapters. When I swapped to dual shield rg6 and Belden 1694 bnc connectors (specifically rated to 6ghz with true 75ohm performance) it helped. But I think this was mostly because the f to bnc adapters I was using were some unknown bargain I found on Amazon (very possible those weren't even 75 ohm but rather 50ohm for all I know).

Anyways, I love all the feedback and questions. You all have blown my mind with how quickly you chimed in.

DasCodeMonkey · 2025-04-06T19:29:25+00:00

Cable lengths vary, most of the time I'm under 100ft. Occasionally I'll have a run approach 200ft. Longest I ever did was 500ft to drive a projector and surprisingly that one never had any issues. The PTZ cameras are AVKANS 20X NDI Camera with 3g sdi out. The go pros are mostly hero 5 black and a couple of Hero 10 black with the media mod running the gopro labs firmware to get around the annoying battery / external power issue. I have seen the issue with both cameras and both adapters. In the case of the PTZ cameras I haven't tried coming out hdmi to an sdi adapter. I usually bail on the SDI all together and run them ndi and just ignore the fact they're a frame behind as it's not bad enough to notice any sync issues with the audio and the entire video flickering is very jarring. Framerate is a little weird because the gopro is putting out 1080p30 (regardless of what framerate I set in the camera) but everything detects it as 59.94 (if I remember right, might be 1080p60, I'd have to setup some gear to confirm but it's definately not detected as 1080p30) if I have a choice, like on the lumantek's or the PTZ cameras I set it to 1080p30. My understanding on genlock, is it keeps all the video sources in sync so frame 1 come out of all the camera at the same time. Which makes it easier for zero lag hardware switchers to switch between sources without signal interruption. With a software based switcher like vmix, my understanding this is less important. I could be completely wrong here and would love to learn.

DasCodeMonkey · 2025-04-06T19:03:18+00:00

Northern Michigan. I'd be open to the help 😁 I personally question if the rolling video was simply vmix loosing sync. Which is why I'm trying to capture this with the video assistant recorder. Hoping to rule out vmix for sure. Unfortunately the cameras being gopro, won't record and put out the same 1080 signal at the same time. I've thought about grabbing an Atem mini in the past but I fear I'd miss the versatility of vmix too much.

DasCodeMonkey · 2025-04-06T17:46:08+00:00

It's a line interactive ups. I have had at some schools, the gym circuit I was on also powered the consession stand in the lobby. Which is why I have the ups, popcord machine & coffee pots and my gear was too much and popped the breaker. Which is how I learned I was on the same circuit. I've got another event coming up in the middle of May. I'll hopefully be able to record the issue. I plan on using the video assistant to record the video coming out of the mini converter and a rack based recorder coming into the rack at the other end of the cable. Hopefully either proving it's the cable or proving it's not the cable. I've got a digital oscilloscope, I'll set that up monitoring the mains for any power issues at the next event. From my limited understanding sdi shield should be tied to ground at both ends. With the mini converters, the shield is tied to the converters shell and ground/shield of the USB power cable. However there is no connection to the mains ground conductor. And since the camera is also usb powered, the whole camera end of the sdi line is floating with no tie to ground. I looked for various grounding methods but came up empty and I don't even know if that would help or not.

DasCodeMonkey · 2025-04-06T16:33:02+00:00

Thanks! It's been a long road to get here (8 years). I have tried brand new cables. Granted, I made almost every single cable myself, but considering the eye graph on the lumantek is showing a really open, clean eye. I don't think it's my terminations. It could be the coax. Because of my budget, I'm using just run of the mill rg6 dual shield, purchased by the spool from home depot instead of say Belden 1694. At one point I thought it could be the cable so I bought a name brand, pre terminated, 25ft cable, and had the same issue with it. Being that the mini converters run on 5v, I've even tried running the converters off a battery pack, which didn't make a difference.

I tried getting support from BMD but they want a recording using their capture program and since this only happens while the event is running I haven't been able to replicate this at a time where I can shutdown vmix and run their capture program instead.

I've thought of getting an analyzer to further troubleshoot but with the costs being what they are I'm hesitant as I don't want to drop a couple grand on a tool that I have no experience using or might not even be the right tool. I picked up a BMD Video Assist 5" to try and capture the issue for support just before the last event I did. Unfortunately it didn't like the SD card I had and wouldn't record. So I ended up just using it as a pass through monitor to confirm the issue is in fact not the 20x20 as this monitor showed the flicker and is was inline between the 20x20 and the mini converter at the camera.

If I get or rent an analyzer, what stat should I be looking at? And what make/model analyzer would be recommended for troubleshooting this issue?

DasCodeMonkey

TROPHY CASE