Bryson Posted May 21, 2004 Share Posted May 21, 2004 Hello all: Some queries on VGA for the massed brain power of the BR: (Big Dave, Brian etc, I'm looking at you.) 1: What is the correct cable to use for VGA installations? (I was kind of hoping for the Belden model number, if you could.) 2: Does it use all 15 connections, or just 10, or just 6? (Common ground) (This will affect the answer to question 1) 3: What is the longest cable run you can do without a line extender? 4: Why do all the line extenders I can see have functions I don't need? (But which I have to pay for..) 5: What is the maximum airspeed of an unladen swallow? 6: Is it permitted to ask this many questions in one post? 7: How about this? 8: Can you tell what it is yet? Link to comment Share on other sites More sharing options...
timmath Posted May 21, 2004 Share Posted May 21, 2004 1) If it's a pukka AV install then use..VDC 268-305 - not sure if they do an install version. - this is being used for a massive hotel refurbishment in london tho. 2) Red+Ground, Green+Ground, Blue+Ground, H Sync+Ground, V Sync+Ground - any other pins are used for monitor to PC Plug and Play Rubbish. 3) Without a DA runs of over 20m lose quality - more noticeable at high res. 4) Extron P/2 DA2 - Good for 100m, and cheep as chips! regards Tim Link to comment Share on other sites More sharing options...
James Posted May 21, 2004 Share Posted May 21, 2004 Hello all: Some queries on VGA for the massed brain power of the BR: (Big Dave, Brian etc, I'm looking at you.) 1: What is the correct cable to use for VGA installations? (I was kind of hoping for the Belden model number, if you could.) Well we generaly use singles of PSF 1/3 2: Does it use all 15 connections, or just 10, or just 6? (Common ground) (This will affect the answer to question 1) 3: What is the longest cable run you can do without a line extender? Well we do about 20 - 30m without too many problems 4: Why do all the line extenders I can see have functions I don't need? (But which I have to pay for..) Beccause it's easier and cheeper to produce a single product that attempts to do everyting than design, manafacture and market a range of products with different specifications to an already saturated market with limited fixed demand requirements. 5: What is the maximum airspeed of an unladen swallow? African or European 6: Is it permitted to ask this many questions in one post? I don't know, Ask a moderator? 7: How about this? Depends? 8: Can you tell what it is yet? Something you prepared earlier? James Link to comment Share on other sites More sharing options...
Tomo Posted May 21, 2004 Share Posted May 21, 2004 1: Not sure. It should a twisted pair for each of the R,G,B and accompanied GND signals, but beyond that I don't know. 2: Everything you ever wanted to know about VGA pinouts:VGA Pinout Pins 6,7,8 are GND for Red,Green,Blue, and pin 10 is GND for the SYNC signal. The DDC pins are not strictly necessary, but the allow data like monitor model number and settings to be transferred. In theory you could get away with 6 cores by commoning all the grounds and NC the DDC pins, but that would reduce the maximum length you can have the cable due to crosstalk issues etc 3: Looking at common lengths, I'd guess that the maximum recommended length is about 10m at 1024x768@60Hz, but good quality cable at lower screen resolutions will go a bit further.If you want much more than that you need a repeater. 4: A lot of them switch to optical and then back so you can go 100+ metres (or further!) 5: Airspeed Velocity of Unladen Swallow 6: Apparently Yes, as you haven't been moderated. 7: Don't think so. 8: It's a rabbit! Link to comment Share on other sites More sharing options...
Tomo Posted May 21, 2004 Share Posted May 21, 2004 Wow, 3 replies within 5 minutes. Blue Room is impressive. Link to comment Share on other sites More sharing options...
Brian Posted May 21, 2004 Share Posted May 21, 2004 First up I recommend everyone gets themselves an ebook called 'The Hardware Book', it's a free PDF file with just about every PC type connector/cable in it. A 15-pin VGA D-typ uses the following pins...1 - Red Video to monitor2 - Green Video to monitor3 - Blue Video to monitor4 - monitor ID bit 2 from monitor5 - ground6 - red ground7 - green ground8 - blue ground9 - no pin10 - sync ground11 - monitor ID bit 0 from monitor12 - monitor ID bit 1 from monitor13 - HSync to monitor14 - VSync to monitor15 monitor ID bit 3 from monitor For long runs you can usually get away with a 4-pair cable, individually screened plus overall screened cable something like belden style 9728. Red, green and blue run up their own pairs, hsync and vsync can each have one wire of the remaining pair. On the RGB pairs common up both of the connductors. As to max distance it's all down to how good the drivers in the source equipment are. For extenders I've always preferred the ones that use CAT5 cable, you can get up to 300m with a 1024x768x72Hz signal. Whilst the boxes may be a gnats more expensive than a pure VGA one, once you factor in cable it's way cheaper. Link to comment Share on other sites More sharing options...
Brian Posted May 21, 2004 Share Posted May 21, 2004 Thinking about your cable a bit, on ship your almost certainly going to need a fire-rated cable. Have a look at Extron VGA cable this is the real deal. It's got 3 coaxes for the RGB, 2 twisted pairs for the syncs plus coductors for the ID bits. Whilst you might not need ID now, who knows what mnitors will turn up later? While you are there you'll find the P2DA that timmath referred to and some CAT5 extenders here. The other good thing is that Extron are big your side of the pond so should be easy to get hold of. Link to comment Share on other sites More sharing options...
Big Dave Posted May 21, 2004 Share Posted May 21, 2004 I'm only going to answer the length bit as the rest has been done. I've run over 300m single line of VGA and the signal was still pretty good - there was a still very small amount of signal degradation but it was only really noticeable on the TFT previews. I've found in the past that using DA's or booster boxes in a long line actually degrades the signal more than if you don't cause all you end up doing is amplifying the impurities. Have used KVM extenders with CAT 5 on certain shows where we have had to simplify monster temporary installs but I have had experience of picture ghosting before on runs of 100m as the signal has been affected by too much EMI from the rest of the rig. Normal practice for long runs, is VGA signal into a 400 MHz interface (such as Procon 6015) then run RGBHV cable to the source. Projection job I did in the Albert Hall last month (I think it's in next months LSI), we ran 5 100m runs of RGBHV & 16A from the rat run, up over the back of the stage and onto the projection truss running 4 Barco G10 (Viewscape edge blended) onto a 8m wide screen and we had no signal or image problems. Link to comment Share on other sites More sharing options...
Bryson Posted May 21, 2004 Author Share Posted May 21, 2004 Thanks y'all. The cat 5 doofer I believe it shall be. Hugs 'n' Barnacles B Link to comment Share on other sites More sharing options...
benweblight Posted May 22, 2004 Share Posted May 22, 2004 ah, monty python Link to comment Share on other sites More sharing options...
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