SDI amplifier

Hi !

I have a gig coming where the my ATEM video switcher will be 320' away from the camera.

The Audio & Lightening rental company provide the LED walls and were supposed to provide a 6x SDI snake (Belden 1694A) in the original talks because the cables were running directly from FOH to stage (164') crossing the crowd but the production changed their mind and now all cables runs on the side. With that type of cable, the max length is 250'

My question is : Is there any pieces of gear that will allow me to amplify the SDI signals that takes minimum 4 distinct inputs and send out to 4 distinct output. 3G is enough for my needs. I was thinking using a 12x12 video hub but I was more looking for something sized like of a mini converter or a decimator.

Thank you

I don't know of anything the size of one decimator, but 4 decimators or mini converters would work. these devices would have to be inline around the halfway point to be effective, putting the device at one end of the cable isn't going to solve your problem. Murphy's law of SDI will probably dictate that the point you need these devices will be right in the middle of a walkway with no power close by.

personally I would run fiber and be happy. but then again, I'm biased

@MambaFiber.com I would love to run fiber but it has not been planned this way when the contract was signed so I have not money for it.

Will the 12x12 video hub work in my scenario ?

We talk about 250 ft, not 250m. 3g SDI should work up to 100m.In Winter I had a 140m connection (3 daisy chained Sommer Cable) driven by a China HDMI to SDI converter....(1080i50)

Maybe you can test the cable....

Any device, which reclocks the signal should work, but it only makes sense in the middle (or near to it), not at the end of the cable.

Decimator MD-HX are swiss army knives, they always are versatile stuff. So I would take four of them. After this event, they can be used for different other things at different locations. A video hub only can be used as a video hub ... at one position.

You could even use 4 BMD Micro converters SDI to HDMI.. They have a reclocked loop tru.. And the best part is that you could even power them from a large powerbank if you dont have power at the point of cable coupling..

But yes i would really do it with fiber.. And that the client decided to re-route the cable trace.. It is their fault.. You offered based on what was discussed.. Any change on the client side would change your setup too and so you could stand up against them and say oke now i have to add charges because you changed the plan.

The Videohub would work, since it reclocks all outputs.

Easiest solution is go to 1080i or 720p. Problem solved. No additional purchase necessary.

I work in outdoor concerts and generally we provide a single sdi to the led wall controller. The led wall company runs all connecting cables to their screens.

POST-MORTEM on this question

The event is past now and here's what I've learned from this gig.

Chronology :
1. The customer first asked 6 cameras near the stage.
2. I gave them my quote.
3. We had a production meeting with the lighting/audio/video wall company, where I learned that the SDI cable run would be 320'.
4. We have a problem, Lighting/audio/video wall suggest fiber and will prepare a quote.
5. Few days later, customer declined my quote for 6 cameras and decided to go with only 3 cameras.
6. Lighting/audio/video wall company quoted 10 000$ for 6 fiber lines (not knowing I now only have 3 cameras).
7. Customer declined the quote for fiber lines.
8. Lighting/audio/video wall quoted for a 6 SDI snake crossing the crowd from FOH to the stage (still not knowing I now only have 3 cameras)
9. Production agreeded the price for 6 SDI
10. Lighting/audio/video wall installed 100' snake + coupler (f2f) + 100' snake
11. I had to add 1x 25' patch for camera #1 (total 225'), 1x 50' patch per camera for camera #2 and #3 (total 250' each)
12. Lighting/audio/video wall gave me sh*t when they see I only have 3 cameras because 3 fiber lines would have been the same price as 2x 100' SDI snake (6 lines).

Day one, both Sony EX-3 at 250' keeps blanking/flickering (example: ), annoying as hell. I cannot put them on big screen.
Day two, I introduce 3 Decimator between the patch of each cameras and the 200' snake, one for each camera. Now I got a blank frame every two or three minutes.
Day three, everything is perfect, no flickering at all.
Day four, everything is still at is place, nothing changed, flickering is back and more intense.
Day five, Instead of using the loopback (output 1) on the decimators, I decide to go trough the DUC (Output 2), still flickering.
Day six, they've installed a cat walk, distence of the camera is reduced. I decided to break the junction at 100' and tap my camera with a 50' patch. Works perfectly.
Day seven, flickering is back, line is too long, cable in the snake is unidentifiable so I can't read the specs
4 days remaining for this event. I'll have to live with it. FML

A. Decimator did not solve the issue
B. They introduced me to the Xvision SDI repeater, from Theatrixx which is 700$ and reclock 2 SDI lines. I might put a few in my tool box for next time.
C. 225'/250' cables at 1080i 59.94 is not viable.
D. I did not try to put a video hub as my "repeater".

cable-mat2.jpg (660.17 KiB) Viewed 5813 times

Decimator2.jpg (706.99 KiB) Viewed 5813 times

Fiber is always the solution.

if you were having issues at 150ft I would suggest the cable installed was not spec'd for HD, or had termination issues. just because the cable has BNC connectors doesn't mean it is appropriate for HD-SDI. where did you insert the decimator, I mean how many feet between the camera and decimator?

for the record, I have run 300ft (actually closer to 500ft) on many occasions using coax with no issues whatsoever. of course it was coax specifically made for 3G-SDI (Belden 1505a). but my first choice here is that I still would have run fiber.

maybe I should state for such short lengths, you should run your own cables and not depend on other vendors. seriously, cable is some of the cheapest gear in our toy boxes. having your own cable also means you can hook it all up before the show and know it's going to work.

If you put the Decimator or an BM Mini Converter with SDI in and Out (eg SDI to HDMI) in the middle of your 100´cables, it should work. Mounting them directly behind the camera won´t help.

Couplers (and the cables) must have the right impedance, you can get them with 75 and 110 Ohms. You want 75 Ohms. The best way is not to use any couplers at all.

Sucks you had to discover this while on gig.

Curious about the "SDI snake" typically those are constructed using Belden 1855A or Gepco VDM230 - a lighterweight cable in bundles (color coded) to make for easier installs in racks - and a "snake" cable that isn't the size of a tree trunk. If that's the case, yeah, 200+ft would be near the cliff.

I'd be watching for clearance sales of "old" AV stuff. The RGBHV cables that were used back in the "old" days to connect and extend VGA were of very good quality. I've got some excellent cables, thick as all getout but work great at conveying the signal.

1.5G HD should be able to travel at least 100m/300ft with no issue, even longer via 1694A or equivalent.

Also, not all SDI source drivers are the same. I did a test with a path of 300' with a camera, worked fine. Day of setup, had to swap cameras, so an analog camera was put at the end of the 300' run with a A/D converter. That was no joy.

You made it through, a few extra bruises and scars. That's the gig life <g>

6. Lighting/audio/video wall company quoted 10 000$ for 6 fiber lines (not knowing I now only have 3 cameras).

100Meter / 320' haspels Fieldcast Fiber costs € 400 euro.. (450 dollar or so)
I rent them for 45 dollars a piece.. But for $10.000 for 6 fiber lines .. They could buy 25 spools of 100m / 320'

Offcoarse you need a few fiber converters too.. But Way to excessive cost..

sdi coax 1505a will go over 100m but is spec'd as such, just the other day in the shop had 425 ft of 50 and 25 ft sections passing test bars to a Harris field scope with very few errors ... the correct coax is imperative at that distance ... but 320 ft is not an issue with 1 single continuous run of the correct cable ... agree with everyone on the fiber though cable is dirt cheap compared to losing a job 10k ... I would have told the client is do it for half that go buy all the parts and be done ... speaking of fiber I asked a while back but has anyone successfully replaced bmd sfp with a wdm single stand solution??

speaking of fiber I asked a while back but has anyone successfully replaced bmd sfp with a wdm single stand solution??

If you buy a video sfp rated for the datarate you need it should work.. BMD devices are not locked to theire sfp's..

got it ... mos of the time its not necessary but nice to know its in the back pocket ... !

has anyone successfully replaced bmd sfp with a wdm single stand solution??

yes. fs.com

not all of their video SFPs pass pathological, and not all are the standard 1310/1550 combo. when you find the right ones however, they work very nicely. shop carefully.

I think the root cause of your problems is that you are way to low on this gig's totem pole. That is: you don't have total control of your product. Now you have to worry about the reputation of your company because you were reliant on others and couldn't call all the shots. I send HDsdi (1080i) down 600' of Belden 1694a all the time. Rock solid and that is from the output of a Sony NX5. Get control of your entire signal flow from camera to customer or learn to live with a series of these problems every gig. Another thought is that once you agree to do one of these gigs - you own it. Matters not what the budget is, the customer only knows that you failed to get it done or that it was a struggle. At times you will have to eat the extra cost of adding proper gear to a gig. A small price to pay to be known as the guys who get it done.