Weird issue with Triplehead 2 Go, Atlona extenders, and 3 projectors . . .

[bbrunskill]

I wonder if any one could shed some light on an issue I'm having. I've installed a TH2G fed from our Mac Mini. I'm using 3x Atlona DVI extenders (AT-DVI15SR) to take the signal to the projectors. The two side projectors are working great (Epsom 3K lumens).

The centre*projector however, is not working at all. If I grab a DVI monitor and use the extenders with a short cat5, the centre output of the TH2G still doesn't output anything. But a straight DVI cable out of the centre TH2G output to the monitor works fine.

Has anyone come across this before? It's almost like the TH2G doesn't have enough ommph to push the signal through the extenders.

[Brad Weber]

If you move the transmitter and receiver that do not seem to be working to one of the other TH2G outputs and the extender pair that were working on that other output to the center output, does the problem follow the TH2G output or the extender transmitter and receiver pair? That should help narrow down if the problem is related to the TH2G or to the extender system.

Are all three projectors the same?

[bbrunskill]

Brad, the issue follows the TH2G output, not the extenders. The projectors are different - near new Epsoms on the sides and a Sanyo PLC-XT35 in the centre. If I plug the Sanyo into the L or R outputs in the TH2G, it goes.

I think I'll get a powered DVI extender and try that.

[Brad Weber]

Originally Posted by bbrunskill

Brad, the issue follows the TH2G output, not the extenders. The projectors are different - near new Epsoms on the sides and a Sanyo PLC-XT35 in the centre. If I plug the Sanyo into the L or R outputs in the TH2G, it goes.

I think I'll get a powered DVI extender and try that.

Do you get an image on the Epson projectors if they are connected to the center output on the TH2G? The TH2G has to be set for one of its compatible resolutions and all three projectors have to accept the signal related to each output, which is the same for all three outputs. So you could have a situation where the Sanyo projector will not accept the resolution and/or refresh rate of the TH2G output. Looking at the information for the the Sanyo PLC-XT35, the projector's DVI input is DVI-D only. Cross matching the resolutions and refresh rates it seems that there are a number of resolution and refresh rate options supported by the current TH2G model that are not compatible with the Sanyo. Matching the two lists of compatible resolutions and refresh rates suggests that 3072x768@60Hz (3 X 1024x768@60Hz) might be the best option supported by both the Sanyo projector's DVI input and the TH2G.

Also on resolution, apparently the Altona units provide EDID information. While one would expect all new units to come with the same default settings, and thus if the two work one would expect all three to work, however apparently the EDID is programmable and this is another place where one device could be establishing a different and/or non-compatible resolution.

However, you may also be on the right path in that it is possible the TH2G will simply not power three extenders. Have you tried having just the center output connected at the TH2G? The Altona units have indicator LEDs and while the manual does not actually say what they indicate, are they lit?

[bbrunskill]

I found another forum with a post complaint of a similar issue. Centre output of the TH2G would not work with a DVI extender.

I brought the projector down and it works fine with the 3 meter DVI cable I have. It's 16 meters from the projector op to the projector mount, so I think I'll just buy a 20 meter DVI cable and hope that it works over that distance.

[Brad Weber]

Originally Posted by bbrunskill

I found another forum with a post complaint of a similar issue. Centre output of the TH2G would not work with a DVI extender.

I brought the projector down and it works fine with the 3 meter DVI cable I have. It's 16 meters from the projector op to the projector mount, so I think I'll just buy a 20 meter DVI cable and hope that it works over that distance.

Okay, but be aware of a couple of things. For one, there are DVI-A, DVI-D and DVI-I cables as well as single and dual link connections. The TH2G output is DVI-I and the Sanyo input DVI-D so a single link, DVI-D cable should work and a single link, DVI-I cable might work if the Sanyo input will accept the extra pins.

I believe that the maximum cable length in the DVI standard is 5m or 16'. There are longer cables offered, but checking several sources no one seems to recommend anything over 25' to 30' unless you use an active/amplified cable or an amplifier before the cable.

[bbrunskill]

I tried a 15 meter DVI-D to DVI-D cable, and it works fine. No issues with picture quality at all. I did buy a higher quality cable, not a bargain bin one.

Our projection setup is looking great now - Song words behind the band, song words over live video (Sunday AM) or song words over visualizations (Sunday PM) on the sides, and a LCD monitor as a confidence monitor. All running off a Mac Mini and Propresenter 4.

[Esoteric]

Did you do your upgrade to V5? You might get a lot of use out of its layering.

[bbrunskill]

No V5 yet - budget for projection for the year is spent . . .