# Bug Free VGA?



## Calvinv (Sep 3, 2015)

Hi
I recently went to a new venue and hooked up two laptops to my Kramer VP-730 (Presentation Switcher/Scaler). Output of that was connected to a pair of Panasonic PT-VX501 projectors.

Problem: No matter what we did, the image size differed when switching between Laptops.
Troubleshooting: 
- Setting both Laptop's output to 1024*768
- Hitting 'Auto-Image' within Kramer's Menu
- Hitting 'Reset to VGA' on the Kramer
- Hitting 'Auto-Image' within the Projector's menu
- Changing VGA cables.
- Doing a Factory Reset of the Kramer.

I finally removed the VP-730 and replaced it with an older Kramer VP-724

The difference between the screen sizes from both laptops very much improved. It was small enough to run the show, but someone with an eagle-eye could have spotted it.

Question 1: What are the best practices to get bug free output over VGA? (Assume no control over the laptops in use)
Question 2: Is Bug free projection with various sources and multiple destinations (for example, a second set of Projectors/TVs 40m down the room) possible with VGA cabling? I have used an unbranded active Balun over VGA which worked well for 3 days, but on the 4th day it randomly had some 'snow' in the image!

Question 3: What do you Pros use for high-wire events...VGA or some other system.

Much thanks in advance!
Cal.


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## ThomasL (Sep 3, 2015)

Different screen sizes sounds like the Kramer does not have EDID Management built into it or that the EDID Management failed on one output. The ones from Extron, Analogway, etc has EDID Management built-in.

Question 1: What are the best practices to get bug free output over VGA? (Assume no control over the laptops in use)
A: You need EDID Management. Since your Kramer does not, a possible solution is to have an external EDID Manager unit for each output. Check out Gefen DVI Detective, DVI Parrot, Lightware EDID Manager. Cheapest of these is the Gefen, about USD100. There is one with HDCP pass through, one without (read: Mac laptops).

Question 2: Is Bug free projection with various sources and multiple destinations (for example, a second set of Projectors/TVs 40m down the room) possible with VGA cabling? I have used an unbranded active Balun over VGA which worked well for 3 days, but on the 4th day it randomly had some 'snow' in the image!

A: Can't say why 'snow' appeared on the 4th day. Best advice is to have spares. I think VGA cabling should run up to about 100yds without a balun. Haven't done that in a while but years back that's what I did - no baluns.

Question 3: What do you Pros use for high-wire events...VGA or some other system.
A: I think Pros nowadays use fibre optics with EDID Management.

ThomasL


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## Calvinv (Sep 3, 2015)

ThomasL said:


> A: You need EDID Management. Since your Kramer does not, a possible solution is to have an external EDID Manager unit for each output.
> 
> A: I think Pros nowadays use fibre optics with EDID Management.
> 
> ThomasL



Super, thanks
That's going to keep me busy for a bit, will get back once I read more about this.


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## Chris15 (Sep 4, 2015)

ThomasL said:


> Question 1: What are the best practices to get bug free output over VGA? (Assume no control over the laptops in use)
> A: You need EDID Management. Since your Kramer does not, a possible solution is to have an external EDID Manager unit for each output. Check out Gefen DVI Detective, DVI Parrot, Lightware EDID Manager. Cheapest of these is the Gefen, about USD100. There is one with HDCP pass through, one without (read: Mac laptops).



Huh?
VGA does not support HDCP, so any reference to HDCP must relate to a DVI-D connection, please be careful and check you have an analog capable device not a DVI-D only device which will cause more issues than it solves here...


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## ruinexplorer (Sep 5, 2015)

First off, how are you connecting to the two projectors? Are you using two outputs from the same unit or are you using some other means of splitting the signal?

If the two images are different going out of the presentation switcher, then you have a scaling issue within it. I haven't used the Kramer models, so it would be difficult for me to walk you through programming it. However, the same signal should be sent through all of the outputs. Once you have that set, especially if you have an internal test pattern that you can send, then set your projectors to match (save settings if possible). After that, don't mess with the output or the projectors, it comes down to making sure that your inputs are set correctly. This is what the scaler is built for. You should easily be able to have the Kramer learn each new input after that, but you don't have to worry about output.

The "snow" you are seeing is from a weak analog signal. Why it developed this on the fourth time is difficult to determine. There could be some signal interference, but that usually shows up as "hum bars", not snow. The problem could be that the amplifier in the balun no longer has the power or it is switched off. At 100yds, I would amplify an analog signal. If possible, use a 5-wire BNC cable which generally is better for long runs than the typical VGA cable if you are not going to use a balun.


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## Calvinv (Apr 29, 2019)

I would like to belatedly thank everyone for their advice, and confirm all the changes I made, in the hope that it will help anyone else searching for the same thing:
1. I finally spent a lot of money and invested in HDBaseT cabling so that I could shift over to Digital signal. With adaptors, transmitter, receivers and HDMI cables, that's an incredible 6 components to replace what one VGA cable would do.
2. I bought a different switcher / scaler with EDID management. This (combined with digital cabling) really helped in getting results that...Work reliably.
3. For anyone asking, the reason I didn't choose HD-SDI is because I need to often work at XGA for many events.
4. Have had bad experiences with 2 different Kramer switchers, and am keep to avoid them for any future purchases.

Again, much thanks to the Forum members who pointed me in the right direction for my research.
Cal.


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## ruinexplorer (Apr 29, 2019)

Thank you for putting up your solution. That is always a value to the forum.


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