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View Full Version : A Couple of meaty Questions


pegFACE
06-12-2001, 7:27 PM
A : How long can I run a 5 BNC -> VGA cable for, and what kind of information is transmitted, analouge or digital?

B : Has anyone scaled a PS2 image using a TV Card and DScaler?

C : Why can a 9" CRT produce better images than an 8" or 7" etc

Thats it me thinks.....

:grin:

Phil Hinton
06-12-2001, 8:24 PM
Interesting questions Young man,

A) Don't really know, but i have a 7 metre run which is high quality, Gordon or Roland maybe able to give the numbers etc.

B) Jeff is the man to ask about this as i believe he scales his with a falcon card and dscaler.

c) Ask Roland or Gordon again (god what would we do without them) But i believe it has a lot to do with the fact the bigger the tube the more detail and resolution is displayed, but i dont know The techy answer to this.

Sorry not much help there, god i need to learn a bit more. Went to look in my copy of HCC for some answers, but i couldn't find any there, but there was a lot of reviews on budget players:rolleyes:

pegFACE
06-12-2001, 8:27 PM
less of the young man you old fogey!

Phil Hinton
06-12-2001, 8:28 PM
Originally posted by pegFACE
less of the young man you old fogey!


he he he he :grin:

helipilot
06-12-2001, 8:31 PM
PegFACE,


My Thoughts :-

A: Probably longer than you would ever need in a home setup provided you use good quality connectors and decent 75 Ohm cable. I have a cable of around 15m with no problems (cost around £90). I hate wires showing so mine crawl through walls and floors to get from HCPC to Projector. As far as I am aware by the time the signal reaches the cable it is very much analog, no matter what technology originated the signal.

B: I have a PS2 running through my system using an IDS Falcon capture card and Dscaler. I use an RGB scart cable which is connected via an RGB to Svideo "black box" before connecting to the capture card via SVHS cable. The image has to be slightly overscanned to make it fill the screen but the results are excellent. This solution would not allow you play DVD's without modifying the PS2 as DVD's are green via RGB! Your HCPC does a much better job of DVD anyway.

C: A 9" CRT has a bigger surface area than a 7" or 8" CRT. This will allow it to produce more light and will allow it to resolve more lines provided it has the hardware behind it to do so. To get the best from 9" you may have to line quadruple. I run a GE Imager 901E CRT (NEC 9 PG) which is considered 7"/ 8" line tripled for DVD at 1280 x 720 resolution.

There are others in this forum who will be able to give you more technical explanations but this should give you some idea until they see your post.

pegFACE
06-12-2001, 8:34 PM
:grin:

Gordon @ Convergent AV
06-12-2001, 8:55 PM
Hi matey!!!

RGBHV is analogue

How long? Well Roland and Richard Ansell are the boys for that. I would agree with Helipilot much longer than you would ever need. I've done 12m ones easy. The key is to use high quality connections well manufactered. I've come across lots of bnc cables and with ringing and all sorts of problems only to find it's the nightmare poor quality manufacture of the connection between cable and BNC

As Helipilot says 9" has more surface area and can be brighter. They also have the ability to draw narrower horizontal lines on their surface (generally). So, if you have a smaller spot size and more surface area it would seem obvious that you could draw more lines across the surface than you could with an 8" or 7" unit.
Even although even a 7" unit can draw all the detail on a DVD there are benfits to scaling to higher resolutions which these 9" units can resolve.

There's a very good thread about this over at AVScience forums. I'll try and find it and post a link here.


Gordon

pegFACE
06-12-2001, 9:14 PM
Hi Gordon

Thanks for your help, I'm going to extend my cable soon i think, as i'm moving the equipment rack into a cabinet...

on another note, the old man got a pair of 803's at a really knocked down price from a dealer (robert richie) who's he's mucked around for years, so tbh, you've saved yourself a bit of hassle!, getting his 105/1's too, i think they are gonna kick some arse...

i'll be appearing in glasgow soon, might drop in and say hello :) any word on the dates for Event II?

RichardA
06-12-2001, 10:27 PM
On the cable length;

It depends

There, thats a good answer isn't it?

No, Oh, OK!

The higher the resolution you run, the shorter the cable run should be - so you can run line doubled/de-interlaced video a lot further than you could 1080P on the same cable.

As a very rough guide for say 768P at 60Hz (cable varies widely as well!)

Multicore cable as found on most normal VGA cables (i.e. probably whats hangingoff the back of your PC monitor) I wouldn't run more than 3 meters

Higher quality cable of this type, maybe 5 meters

Seperate co-ax, stranded core 'composite video' or 'digital audio' cable 10 meters to 15 meters

Solid core, twin screened 'SDI' cable (e.g. Belden 8281) 20 meters plus.

Note that the connectors and connections (i.e. integrity of crimps and soldering) has a big effect as well.

Correctly assembled crimp BNC connectors have minimal loss compared to a soldered VGA connector. Losses in a BNC connector will be less than the effect of poor cable.

Roland @ B4
07-12-2001, 1:18 PM
A length of cable.
Provided the cable is of good quality I have not seen problems up to about 5m any more than that and really it should be boosted with an interface box.
It not so much quality of signal but quantity. The signals you are sending are not muc above 1 volt. but that down a long copper wire and it will have a resistance which will make the signal weaker and you have to turn the bightness up to compensate for the low signal.

B I haven't but I know it will look quite strange. these are quite low resoloution pictures from a PS. expect to see some artifacts

C. the larege the area the more lines you can right the more information you can get on the screen. However I would mach rather see a 7 or 8 inch projector with a good scaller. Than a 9" with an average one.
If there are issues with the scalling device expect a 9" projector to show them.

Jenz
07-12-2001, 3:09 PM
B : Has anyone scaled a PS2 image using a TV Card and DScaler?

In my set up I have run Gamecube, PS2, N64, and Dreamcast through this setup using a S-Video, a Falcon Card and DScaler.

Had to make sure they worked :D

Super Smash Brothers Melee at 10Feet!