Member Avatar for bigpoppapumpg

just started using a belkin pro series 8 port kvm with highest quailty cables available. it still degrades the video signal going to my 21" flat screen dell trinitron. I am told there is nothing i can do about this, all kvms reduce video quality at least somewhat.

If I were to change monitors, might this improve the situation? the kvm video looks too bright and washed out, not as sharp and i can sense the eye strain within a few seconds of looking at the screen... which didnt happen before the kvm. Would an LCD monitor look better with the KFM feed?

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  • Latest Post Latest Post by kc0arf

Dani AI

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Short expert summary and practical checks

The symptom described by (bright, washed-out, soft image appearing immediately after the KVM) is typical of analog-video loss: every extra connector, adapter or long run reduces high-frequency detail and can upset the monitor/graphics card handshake, producing wrong gamma/contrast and a softer image. As hinted, OSD and driver tweaks can hide some of it; as noted, a software switch removes the analog path altogether.

Quick, practical troubleshooting (do these in order):

  • Bypass the KVM and connect the monitor directly to each PC to confirm the KVM is the source of the change.
  • Confirm CRT settings: run the monitor at its recommended resolution and highest comfortable refresh rate (higher than 60Hz for CRTs). For LCDs, use the panel’s native resolution.
  • Use the monitor OSD and the video card control panel to set brightness/contrast/gamma and a 6500K or "sRGB" color temp. Avoid excessive brightness relative to room light.
  • Swap to a short, well-shielded VGA cable with ferrite cores; avoid adapters. If signal still weak, try a KVM with active video buffering or EDID/DDC pass-through (or an EDID emulator).
  • If budget allows, move to a digital path: DVI/HDMI-capable KVMs preserve pixel integrity on LCDs. Otherwise, consider software solutions (VNC/Synergy/Barrier) to eliminate hardware switch loss.

Notes on eye strain and tradeoffs: CRTs suffer visible flicker at low refresh rates; LCDs typically remove scan flicker but can show motion blur or backlight PWM flicker on some models. For immediate relief prioritize correct refresh/resolution and proper brightness; if the KVM cannot preserve those, a digital KVM or software switching will give the most reliable improvement.

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Member Avatar for Killer_Typo

just started using a belkin pro series 8 port kvm with highest quailty cables available. it still degrades the video signal going to my 21" flat screen dell trinitron. I am told there is nothing i can do about this, all kvms reduce video quality at least somewhat.

If I were to change monitors, might this improve the situation? the kvm video looks too bright and washed out, not as sharp and i can sense the eye strain within a few seconds of looking at the screen... which didnt happen before the kvm. Would an LCD monitor look better with the KFM feed?

have you tried adjusting the monitor so it doesnt look like that?? i know right after i got my monitor it was so bright it looked almost white but all i had to do is lower the brightness and work a little on the contrast and it came out perfect.

Member Avatar for bigpoppapumpg

sure tried that, the problem is with KVM switches. I am told that all of them degrade the video signal somewhat. I guess they make DVI kvm switches for lcd monitors that do not suffer from this, but those switches are expensive.

Member Avatar for kc0arf

Hello,

Any switch / additions made to the monitor cable will cause a degration. That is because you lose signal every time you make a connection. In the RF world, adding a double-barrel-female connector to splice two coax cables together can knock the signal down 50 percent!

You do not mention what other computers you are trying to remote control. I am in a similar situation... and instead of a KVM switch, I use VNC to have one master computer remote control the rest of them. SO, the Linux box remote controls the Windows Server, and the Mac Server and a third computer. I wish that VNC would remote a Novell Server, but with other tools, I can manage that thing.

Christian

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