diy projector from the Philippines

[Hezz]

Hertz,

It all comes down to your priorities. If you want the best picture quality and flexibility for the lowest price than build a dedicated HTPC. It does not have to be in an expensive case. Mine is a $15 used desktop case painted black. Nor does it have to have the most expensive hardware to work well. For about $400 you can build a nice basic HTPC.

If simplicity and ease of use for novice users is the highest priority then try to find a component to VGA convertor that will work. However realize that you will not be getting the same quality with this as with the HTPC because the HTPC does all of the scaling in the digital domain as Ace has said. Also the HTPC uses the progressive scan information on the DVD by default.

If you get a scan convertor you will be converting from the analog component outputs on your DVD player into a VGA signal which will be 600 x 480 and the Lilliput will not be able to utilize it's full native resolution so you will have degradation on two fronts.
One with the analog to digital conversion and the other with a loss of resolution because of not using the native resolution of the LCD.

I don't believe that any of the inexpensive convertors will output 800 x 480. And most of the expensive ones won't either. The scalers that have that flexibility and many higher resolutions are quite expensive in the $3000 - $4000 price range.

If you study what the high end home theaters are doing you will find that they are using HTPC's because that give them the best picture quality and flexibilty.

Hezz

[Hezz]

Another benefit of the HTPC is that you can make a HDTV reciever for a reasonalbe cost that can recieve both satelite and air reception.

ATI is coming out with a reasonabliy prices HDTV card this summer that will cost around $200 or less I think. Check out this preview. Using your computer you can scale the digital image in the digital domain to fit your projector for the higest possible quality.

http://www.hothardware.com/viewartic...id=331&catid=2

Hezz

[bfourcade]

Hi HertzBlaster

Since i have a progressive scan dvd player, all I need is just a simple component to vga adapter ( no electronics needed ) just like this one
http://store.infocus.com/escalate/s...tname=&tab=desc

This type of cables works for devices that can receive component signal over the standar VGA connector. It will not work if your monitor cant decode component signal on the VGA input. It was used on some devices ables to receive both (VGA and Component) on the same VGA In connector.

Please correct me if I'm wrong but in memory, VGA uses 4 o 5 signals R , G , B and Sync (Horizontal and Vertical Sync could be mixed in composite Sync), Sometimes Sync signals come with the Green signal.
But Component has only 3 signals Y, Pb, Pr (for progressive) or Y,Cb,Cr (for interlaced) and they stands for Y=Luminance and sync, Pb or Cb (Green minus blue) and Pr or Cr (Green minus red) or something like that, so in the counterpart the 3 color signals can be decoded when Pb and PB are combined with the luminance (Y signal or total). So you can not feeed a VGA device with component signal because the signals are combined in an special way (substracted). You can do it only if the device can decode the component signal coming on the standar VGA connector.

Hope it makes sense and sorry about my bad english.

Bernardo.

[hertzblaster]

Thank you guys for all your response. I feel I am now a learned man in just a few days.

!. you are all right when comparing computer quality vs dvd quality. Computer quality is much better than dvd quality because I can use the LCD native resolution which is 800X600 vs 640x 480. All upscaling done in digital domain.

2. DVD palyer has the advantage of ease of use and thats all I know of. instant play. the biggest convenience is the remote control.

4. BTW, i have the best of both world.

5.When u buy new generation dvd player, a lot times it has progressive scan. Please don't miss dvd player with vga output so there will be no need for a transcoder.

6.Progressive component to vga transcoder costs between $50 to less than $200. Circuit components are fairly standard. Add on feaures dictates the high price.

6. My PC is located a liitle away from my PJ so i need to diy a vga cable which is made of cat 5 cable. it could be about 6-8 meters away without loss in quality. Is this right? has anybody tried cat5 as vga cable? They say cat5 can be as long as 50 feet.

7. Vga to component adapter will only work on infocus x1 and other models. ( no electronics involve)

I have athlon xp2400+ system. My vga card is GF4 4200ti. I am thinking of upgrading to vga card with a tuner. i am now searching for a video card. Any recommendation? Will add-on tuner card be cheaper? Has anybody compared the performance of ATI vs nvidia card in terms of video quality?

Thanks a lot. Please feel free to comment on the above summary.

[Hezz]

Hertz,

you can make a very good VGA cable with CAT5 cable but there are some internet sites that carry pre made high quality VGA cables. For a long high quality cable you will need to do more than just add connectors.

I would do a search because you can probably buy a high quality shielded VGA cable cheaper than you can make one for.

Do a search because a few weeks ago there was a thread on this and there are some good links and information.

Here is a link to company that sells high quality long VGA cables:


http://www.mycableshop.com/sku/CVGAM25.htm


Hezz

[hertzblaster]

Hezz,

Thanks a lot for making things easy for me. I have excess cat 5 cable from my diy speaker cable. I plan to use cat5 as vga cable first. Will show u the results later.

Hertz

[Altec]

Uh, dont forget the ferrit core. Or youll get major interfearence. About $2.00 at radio shack or electronics shop. Ya know the round thingy molded on end of vga cord at vga card output and mon input. One for each end is used. It does help alot. Specially on cords that arent shielded well and when using high refresh rates.. A REALLY well high end vga cord needs no core. But I havent seen one like that for about 2 years. THe local mom and pop pc shop had one for really long vga runs to pj in the lab. Ha, $10 per foot. Eh, I passed used ferrit rewired my vga mon was simple and works 110%! Like they said if under 10' or so run use ferrit and not high end cable as you will see no benefit. Course if you wanted top output to the lcd youd use the dvi output.

[hertzblaster]

Altec,

Thanks alot for your suggestions. I will do it also if ghosting or interference will be evident without ferrite core.

Hertz

[bfourcade]

Hi !

If you will use Cat5 cable for a long run VGA extension you will want to use Shielded CAT5 cable.
One of the mayor troubles on long run video cables is total Impedance on cable and connectors. Cat5 cable is 100 Ohms (impedance) and Video devices and circuitry works with 50 Ohms cables. Such diference in Impedance values will put a lot of undesired effects on the signal (ringing, and especially Ghosts, the higher the frecuency of the signal the higher those artifacts appears). But some people where able to make medium distances run VGA cables with CAT5 shielded cable. You must assure to sold the Shield to the ground pin on both ends and sometimes sold all the grounds together. VGA connector have 1 pin per color signal and 1 pin per color ground. Sometimes you need to sold in the connector all the grounds together.
By soldering the shield to the ground it changes the Impedance on the cable to something more close to the 50 Ohms needed.
With my component to VGA adapter I've decide to run 3 separate 50 Ohms cables to carry the component signal from the DVD player to the adapter on the projector side and to use the short Liliput VGA cable to carry the VGA signal because for the moment I cant get shielded CAT5 locally.
I have the VGA connectors ready waiting for STP availabilty in order to run only one cable and put the adapter near the DVD player.
Hope it helps.

Bernardo.

[hertzblaster]

Bfourcade,

Did you mean 75 ohms? As far as I know, we need video cable with 75 ohms impedance for analog video signal.

I tried using cat5 cable for s-video and I got crappy result. I already have vga female and male socket. Its going to be a chalenge to solder cat5 cable to this vga socket huh? BTW thanks for ur suggestions.

Hertz