[GRLUG] VGA / video question

John-Thomas Richards jtr at jrichards.org
Mon Mar 23 20:38:19 EDT 2015

On Mon, Mar 23, 2015 at 11:16:00PM +0000, Thad Ward wrote:
> > From: John-Thomas Richards <jtr at jrichards.org>
> > On Mon, Mar 23, 2015 at 09:23:54AM -0400, Dave Chiodo wrote:
> >>  How many screens? Could co-locate a Raspberry Pi with each one, connected
> >>  to to Ethernet? Then either run the software separately on each one, or use
> >>  some sort of network screen mirroring like VNC?
> > 
> > Running the software locally at each display (two large, one small) is
> > not an option as the slides have to be advanced manually.
> > 
> > I've tested the set up with much shorter cables and I get full 1080
> > resolution. Unless I'm missing something entirely, this sounds like a
> > signal issue (as Mike indicated). The question then becomes whether to
> > buy a VGA signal booster for the longest length of cable (the one from
> > the laptop to the VGA port splitter) or go with VGA-->CAT5-->VGA
> > adapters. I don't really need much flexibility since this is installed
> > and no longer mobile.
> I've used a few different cat5/cat6 extenders for doing video at conventions, both
> with VGA and HDMI. One location we used shielded cat6 with one of these (or some
> other brand that looked identical) to run the video a few hundred feet (including
> a coil of excess cable backstage)
> http://www.amazon.com/StarTech-com-VGA-Monitor-Extender-feet/dp/B002KQ6ZD8/
> I don't know why there is only one power adapter in that one, though. There should
> be one for each end. The "two power adapters" option appears to be a different
> model entirely, with two VGA ports at each end and lower maximum resolution.
> Regular cat5e will probably be fine for the run. I think the cat6 STP was overkill.

I actually spoke with a Star Tech (the manufacturer) rep today. He said
converting that many times would likely result in too much signal loss:
VGA (analog) to CAT5 (digital) back to VGA and then to HDMI (digital). I
was impressed when he told me that what I need is not a product he
It is not what we do, but also what we do not do, for which we are
Moliere, actor and playwright (1622-1673)

More information about the grlug mailing list