VGA cable length

9006 Views 20 Replies 5 Participants Last post by Danny, Feb 9, 2008

toecheese

Discussion Starter · Oct 27, 2007

I'm getting some pressure for the wife to finish the HT. One of the things we love to do is play Dreamcast on the big screen (Sega fishing is a blast when it is big).

My projector (Sanyo PLV60) has a lot of inputs, one of them being BNC, and the other being a straight VGA 25-pin connector.

If I use a relatively short VGA cable, everything seems fine- both the PC at any resolution and the DC going through its VGA adaptor.

However, when I use my two long VGA cables spliced (sorta- they are VGA to BNC and I have BNC-to-BNC connectors) together in the ceiling in a long run, the PC doesn't work at all (projector seems to keep trying to sync to the higher-than 480 signal) and the Dreamcast won't show red colors.

I assume this is analog signal loss over the long run (35') of cable (though I'm at a loss why red is lost first?).

A couple of questions:

Will a dedicated VGA cable using very-high-quality cable be enough? I'm considering building such a cable.

How about a VGA booster? I've seen some devices that plug in-line which claim to be able to send a VGA signal up to 80 meters.

1 - 20 of 21 Posts

toecheese

Discussion Starter · #2 · Oct 27, 2007

I know that digital is better for longer distances- however that isn't an option- my projector is analog-only and there's no digital output for the Dreamcast.

One option is not to use the VGA cable end at the projector. I've read that the 25-pin connector is a relatively terrible connector.

Oh- and one more consideration is that I will have two sources sending over the same cable, so I guess I want to use a VGA switcher box?

Ideally, I'd want something that could take all my analog sources and send them over the same wire, so I don't have the regular component plus the VGA cable going.

Mike P.

· #3 · Oct 27, 2007

Splicing 2 cables together usually introduces interference especially over long runs. I had the same problem as you trying to splice cables over a 25 foot run. My solution was to buy the proper length quality VGA cable.
http://www.networktechinc.com/cgi-bin/keemux/vext-35-mm.html

toecheese

Discussion Starter · #4 · Oct 27, 2007

Mike P. said:
Splicing 2 cables together usually introduces interference especially over long runs. I had the same problem as you trying to splice cables over a 25 foot run. My solution was to buy the proper length quality VGA cable.
http://www.networktechinc.com/cgi-bin/keemux/vext-35-mm.html

Heh, you're good! You had the same problems as in not being able to get sync, or losing colors (or both?).

I'm still wondering if I should get the cable VGA-BNC to make it even better?

Can you vouch for the quality of that cable? Only thing that would make it perfect were if i had a right-angle male connector on one end, but my hushbox was made big enough to manage.

Mike P.

· #5 · Oct 27, 2007

I had sync problems until I bought the proper length "lossless" cable. I can vouch for the quality lossless cable as that's what I purchased to correct my problem, although it was a different brand. My application was for a 15 pin VGA cable. You mention a 25 pin connection so you'll need an adaptor of some sort, I think.

toecheese

Discussion Starter · #6 · Oct 27, 2007

I'm sorry- you're right- where did I get that 25-pin from- VGA is 15- duh.

Okay, if it worked for you, that's what I'll do. Thanks- though I need to pad the order with them to make it worthwhile with the shipping.

I'm curious how they claim lossless- I guess that's why they put the spec it can handle along with the length. The one you picked handles up to 16x12, so that's the best.

Thanks again

Mike P.

· #7 · Oct 27, 2007

If shipping is an issue with them then see what other places are charging for the cable plus shipping. A Google search for "35 foot VGA cable" will give you all the results you need.

toecheese

Discussion Starter · #8 · Nov 4, 2007

I've found other places, but none of them claim the lossless for the 35-foot cable. That monoprice place had them very cheap, but no info or specs.

Mike P.

· #9 · Nov 4, 2007

Look for lossless, no ghosting, or no degradation in the description.

http://www.vpi.us/cable-vga.html

http://www.montest.com/vga-cable.html

http://www.networktechinc.com/cgi-bin/keemux/vext-35-mm.html

lcaillo

· #10 · Nov 5, 2007

There is no such thing as lossless VGA cable. The loss may be minimal but there is always loss. Beyond about 30 feet with most cables it will be noticeable at most modern resolutions. Look for the cables with the lowest loss and be skeptical of any that claim to be lossless for analog.

Mike P.

· #11 · Nov 5, 2007

Agreed. The better quality cables are of heavier gauge then the cheaper cables. I've tried both and the skinny, cheaply priced cables cause problems on long runs. You get what you pay for.

lcaillo

· #12 · Nov 5, 2007

True, you get what you pay for...but I always add that you get what you pay for if you do your homework and you are lucky. Just paying more without checking the details can be a waste.

Mike P.

· #13 · Nov 5, 2007

Yes, that goes without saying. Always do your homework. I wish I new that years ago when I bought a Philco Ford TV.

toecheese

Discussion Starter · #14 · Nov 5, 2007

Most of these sites do *not* give specs. That's what bothers me.

Mike P.

· #15 · Nov 5, 2007

Vpi.us shows the cable size, the length it's good for, ohms, and the resolution it supports. Montest.com shows cable size, coax type, length it's good for and resolution it supports. What other specs are you looking for?

toecheese

Discussion Starter · #16 · Nov 6, 2007

Heh- looking at all three of those sites... they're all the same one- or at least ship the same product. VEXT-35 was the common name for the part.

I don't have a problem with the $38 for it, so one of them will be bought today

toecheese

Discussion Starter · #17 · Nov 6, 2007

Hey Mike- what do you think of this one? Half the price... http://www.pccables.com/cgi-bin/ord...9&search=VGA_M-M&rsite=pccables.comcgi&rcode=

Mike P.

· #18 · Nov 6, 2007

I'd contact them first and find out what size of cable it is since they don't say on the website. Also ask about their "No Shadow Guarantee ", and check their return policy if the cable does have a problem.

toecheese

Discussion Starter · #19 · Nov 13, 2007

Okay, I listened to Mike- and got a terse email back that it was AWG28- which is fairly thin- but it matched the other sites who had similar cables.

Got it today- and it works great! Woohoo!

So, I was satisfied with PCCables.com if anyone is looking for an inexpensive cable that performs well.

Scotty79

· #20 · Feb 6, 2008

thanks for the update, will come in handy.

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