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Workshop Workshop Video/Audio Distribution

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Hurty
(@hurty)
Posts: 108
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Topic starter
 

Hello All, After struggling with some Broadcast rack mount kit over the years and watching Crusty's workshop video/audio revamp I decided to investigate a rewire of my V/A distribution.  Purchased a small 16U rackmount unit that would fit under the workbench. I do have a lot of domestic and some professional video equipment, most for feeding the internal r.f. distribution system for running the television collection. My existing video/audio location was becoming unmanageable sitting on a shelf.

AV Old
Rack Mount Kit

Also needed some space for the new SDI router and Recorder

New Kit

I was thinking I could possibly get this done over a couple of weekends, that proved not to be the case. So started the strip out, this took some doing.

 

Stripout2
Stripout3

As I went on I was thinking "What are you doing"?

The kit I have to put in the new bay will be 2 X Tandberg Satellite encoders used for Amateur Digital TV transmission, the 2 X existing Kramer 16 X 16 Video/Audio Routers equipped with RCA Stereo unbalanced audio connectors, 1 X Kramer 16 X 16 Video/Audio Router with stereo balance audio connectors, 1 X Extron 8 X 8 Video/Audio Router, 1 X SDI Blackmagic  20 X 20 SDI Router, 1 X MRG Teletext Insertor, ! X Leitch DPS575 Video/Audio Processor/Time Base Corrector and 1 X Tektronix TPG20 Test Signal Generator.

All kit mounted in the new Bay with a rear view. Looks a bit daunting with all those cables to be connected. This is when I thought "what have I started".

New Bay Back
New Bay Front

 Then comes the sorting out the old cables to see what can be re-used and making new ones, many of them. The video cable I use is called Image 360. It is very low loss cable used in broadcast installations for analogue and digital video distribution. It is just under 5mm thick, twin screened, foam insulated with a solid copper inner conductor. There are two colours I used, green for composite video and turquoise for SDI. For those that don't know about SDI it stands for Serial Digital Interface and carries the Video and Audio signal in a single coax cable. If you want to learn more then look up the SMPTE 259M (Standard definition at 270Mbit/s), SMPTE 292M (High Definition at 1.485 Gbit/s) and SMPTE 424M Hi Definition at 2.97 Gbit/s. There is a nice Tektronix publication about the SDI standards called "Guide to Standard HD Digital Video Measurements, I call this the broadcast Engineers Bible, for those who what to learn more.

Now to the Installation of the new cables

Wiring Start

Wiring Start

 

Under Bench Cable Runs

Under Bench (2)

More Cables

More Cables

 

In Broadcast installs Cables are bundled and tied together very neatly but mine are not as I will need to make changes now and again so loosely laid together.

This installation has take me a couple of months to complete but here is the final result

NewInstall
SideView

Its finally up and running now but as you know the saying goes "Why is a Radio never complete?, because it is always a wireless". Same in this install, missing one video cable, one audio cable and a Y. B-Y, R-Y cable but in a much better place to add now. 

The Pi generated BBC COW is in there with the Pi Teletext generator and convertors to and from Composite and SDI with 4 X Stereo balancing units.

The only Items I'm awaiting now are a twin PPM audio meter and twin Stereo VU meter..

Adrian

 

 
Posted : 06/01/2024 1:46 pm
jcdaze, slidertogrid, Lloyd and 1 people reacted
Lloyd
(@lloyd)
Posts: 1933
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That’s a lot of cables!!

The place I used to work made little SDI video recorders, great fun 🙂

 

 
Posted : 06/01/2024 4:57 pm
Cathovisor
(@cathovisor)
Posts: 6436
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I've got some of those MRG data bridges as well as the Tandberg encoders - ASI input by any chance?

 
Posted : 07/01/2024 12:48 am
Hurty
(@hurty)
Posts: 108
Estimable Member Registered
Topic starter
 

Hi Cathovisor. The Tandberg Encoders are Composite and SDI Video in with analogue audio for the composite. They upconvert direct to L band output and feed a homebrew amp which takes it up to 35 watts which feeds a 24 element loop yargi. These units also have a receiver board fitted but I don't use that.

The MRG unit I bought ex-broadcast advertised as a DTP500 but when it arrived it was a DTP600 I was non to pleased about that as that is SDI in and out. Have to have a composite to SDI convertor to feed it and use the composite monitor output for the main output. I have not found a manual for the DTP600 yet so if you have a copy would love to see it/copy it.

Adrian

 
Posted : 07/01/2024 10:34 am
Cathovisor
(@cathovisor)
Posts: 6436
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@hurty No map, I'm afraid. I'll have a look and see if I have a DTP 500 in the store: within a year or two I'll be selling off all my broadcast and test equipment anyway as I plan to wind my company up.

I see that an auction house in the North-west has got a GNAT* on offer from the BBC Collection.

 

*Generator, Network Analogue Time. Or network clock, if you prefer.

 
Posted : 07/01/2024 2:42 pm
Hurty
(@hurty)
Posts: 108
Estimable Member Registered
Topic starter
 

Hi Lloyd and Cathovisor, Yes there are a lot of cables. I used to use small mechanical switches but these can only feed one source at a time. Eventually moved to a matrix, this then growing to two matrixes then requiring a balance audio matrix for some of the Broadcast/Professional gear then SDI. Analogue matrixes are becoming harder to find these days.

Cathovisor, don't know if you can help but I'm looking for a Murraypro pico dual PPM meter if you come across one?

 
Posted : 11/01/2024 8:59 am
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