Sync issue when using a video distribution amplifier

[cr4zymanz0r]

I'll keep this short and simple. I got a cheap Radioshack component video distribution amplifier (this exact one http://www.amazon.com/dp/B00B2MQD92) so that I could output RGB to my XRGB-3 (to HDTV) and to a RGB to component converter (to a CRT).

With RGB going straight to XRGB-3 I have no issues, but when it goes through the distribution amplifier before-hand I lose the video signal on some quick screen transitions or bright flashes. One easy example is the intro of Samurai Shodown 2. I made a quick video showing the issue in action: https://www.youtube.com/watch?v=Y_peLl3iCpE
The issue 1st crops up at 15sec.

Now I narrowed down that the issue is sync (composite video as sync in my case). If I run RGB through the distribution amplifier but leave sync separate then everything still works fine, but once I route sync through the amplifier then I get the issue as shown in the video.

What exactly is the issue here? Is sync too strong or weak? Can I simply do something like add a 75ohm resistor to sync somewhere after the amplifier to fix the issue?

I'd like to hear some input so I hopefully correct this the right way rather than trying something random that appears to work, but then has another issue later after I hook up all of my video set up .

[BuckoA51]

Well known and documented issue with the XRGB3. Actually surprising that it works when not going through the switch (usually doesn't make a difference). Switching to clean composite sync (ideally tapped from the console directly rather than through a sync cleaner) almost always cures it.

[cr4zymanz0r]

Well known and documented issue with the XRGB3. Actually surprising that it works when not going through the switch (usually doesn't make a difference). Switching to clean composite sync (ideally tapped from the console directly rather than through a sync cleaner) almost always cures it.

I don't have the issue when using composite video as sync without the video distribution amplifier. I'd much prefer working towards a solution to just alter the sync/composite video coming from the amplifier to the XRGB3 vs rewiring cables for 12 consoles.

[Fudoh]

You can always try a stripper (LM1881) between the splitter and the XRGB-3.

[BuckoA51]

I don't have the issue when using composite video as sync without the video distribution amplifier. I'd much prefer working towards a solution to just alter the sync/composite video coming from the amplifier to the XRGB3 vs rewiring cables for 12 consoles.

Best of luck with that, I'd certainly start with Fudoh's suggestion. Try inputting into the D-Sub 15 input at the back of the XRGB3 too.

[cr4zymanz0r]

I don't have the issue when using composite video as sync without the video distribution amplifier. I'd much prefer working towards a solution to just alter the sync/composite video coming from the amplifier to the XRGB3 vs rewiring cables for 12 consoles.

Best of luck with that, I'd certainly start with Fudoh's suggestion. Try inputting into the D-Sub 15 input at the back of the XRGB3 too.

I'm actually already sending the signals to the D-Sub connector in the back.

After I got home I tried a couple of quick and dirty solutions with less than stellar results:
1.) Put a potentiometer on sync (composite video) going to the XRGB-3. Adjusting this helped some, but did not completely resolve the issue. Also, if I kept turning it the effect lessened even more but then I started getting wavy jittery movement in the image .

2.) Tried just hooking sync (composite video)straight to the XRGB-3 and my RGB to YUV (to CRT) adapter at the same time without using the video distribution amplifier. This surprisingly improved things a lot, but still didn't eliminate it. The issue was no longer present in the Samurai Shodown 2 intro, but it still persisted during certain screen flashes in game.

If I want to do anymore troubleshooting on this setup I guess I'll need to get a LM1881 to make that sync stripper circuit.

However, I did figure out a work-around that I'm considering pursuing. Currently I'm routing RGB, sync, and audio over standard RCA jacks/audio/switchboxes. I had a small unpowered 3 input component switch laying around for testing. It doesn't have composite, so there's not enough ports for RGB, sync, AND both audio channels but it was still enough to test a video theory. I connected the output of my main switch to the output of of the smaller switch, then connected the XRGB-3 and RGB-to-YUV adapter to the inputs (to use the switch in reverse as a 1 input, 3 output switch).

With that test setup I could switch between the HDTV (XRGB-3) and CRT (RGB-to-YUV) with no issues. Of course I can't output to both simultaneously this way like with teh video distribution amplifier, but that was more of a cool factor than a practical use. So if I grab another 2 or 3 port unpowered component switch that also has composite jacks then I should be good for this approach. Buy a switch and things work but only on 1 display at a time.......or buy a LM1881 and hope it fixes things and output to both displays at once. Decisions decisions...

[BuckoA51]

Wow, is it really that much hassle to get clean sync cables?

Remember that many component video switches do not pass RGB correctly, since the bandwidth required is slightly higher than when routing Ypbpr.