Screen ripple

[pbc_avcontroller]

Has anyone experienced a screen ripple during their church services? (I know it's probably not specific to Zionworx, but that's what we're using)

We had narrowed the cause down to our Induction Loop Amplifier but now think it's connected to a conflict between the VGA cable connecting the laptop to the projector -- it is a 20m VGA cable and I'm assured by the supplier we got it from that it is a shielded VGA cable.

During our latest trials to get to the bottom of the problem it was eliminated by running the cable away (at right angles) from the projector as opposed to, effectively, straight back as this is parrallel to the cables for the PA/ Loop system. This worked and stopped the ripple, but the operator for the PA System and Zionworx is the same person and needs to sit beside the PA controls.

Just wondered if any other church had experienced similar problems?

Ewan

[vetto]

I have it when the contrast and brightness on the projector is too high...but we are using a wireless transmitter/reciever for the computer to projector link.

I am interested in the cable routing you mentioned...did you mean that your VGA cable was routed along side the PA cables?

[webmaster]

As a once installer of loop amps, pa systems and the like for churchs.

The problem is the loop amp causing current to be induced into the VGA cables.

Further sheilding on the VGA cable will help and /or routing the VGS cable further than 3 feet from the loop cable....

Or what I have fouund works ok is a CAT 5 extender as this turns the standard VGA into a balanced VGA signal which is less prone to the induced signals.

If you need further help feel free to email me direct.

Regards
Edd

[mikeyp]

we just bought this (http://cpc.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=CS10932&N=411), and couldn't be happier, we've run the cable 40-50m (could be upto 150) and have no problems at all...

As it also works as a vga splitter, I've now got a screen by me, and we've got a 19 inch crt for the singers on the stage.

[vetto]

We use those at work to route complex runs around the ship...yes I work on a ship.

Never had a problem with them, there are many different brands of these and I would recommend them for long runs.

[paulstokes]

Mike,
What is the image quality like on those? We have a long VGA cable (15m) and there is some inevitable shadowing on the screen. PC is 1024*768, but projector's max is 800*600. Are the CAT5 extenders better quality as far as the display image is concerned?
Paul

[mikeyp]

If you mean shadowing like you get ghosting on a tv, then there is none. If you look VERY hard you can see a very and small slight bright shadow outlining the text, but it's not noticable once you stand back a bit.

Other than that, I can't fault the picture quality. The colours are as rich as if you had the laptop directly connected to the projector through a short vga cable, and the images are nice and crisp.

It works at a max resolution of 1024x768 @ 60Hz, and like you our projector has a maximum resolution of 800x600.

[webmaster]

I have found these far better than using longer lengths of VGA cable we used to run 20m VGA lead now we run 2 lengths of Cat 5 and this probably exceeds 40m as we have hidden all the cables from the public eye.

We ran 2 as we will go HDMI and these extenters need 2 cat5 leads so it was easy to do all at the same time..

Being in the AV industry I am aware HDMI will over take VGA at some point so being ready now makes sense.

Our new projector will have HDMI/DVI and most ne video cards will have a HDMI output too.

Just my 2p's worth.

Regards

[mikeyp]

I have found these far better than using longer lengths of VGA cable we used to run 20m VGA lead now we run 2 lengths of Cat 5 and this probably exceeds 40m as we have hidden all the cables from the public eye.

We ran 2 as we will go HDMI and these extenters need 2 cat5 leads so it was easy to do all at the same time..

Being in the AV industry I am aware HDMI will over take VGA at some point so being ready now makes sense.

Our new projector will have HDMI/DVI and most ne video cards will have a HDMI output too.

Just my 2p's worth.

Regards

took the words right out of my mouth
We've done exactly the same....

you sure you're not from my church?

[webmaster]

No I am sure I go to the Salvation Army in histon, Near Cambridge

Regards
Edd Stonham