CurtPalme.com Home Theater Forum

[Decibel]

I finally mounted my modded BG808@808s LC in his place.

I had big problems in geometry because the projector (then images) had mysterious raster distorsions.
Now I definitively made the choice to switch the video signal through port 3 then the problems are finally solved.
Please tell your experiences.

[km987654]

[ElTopo]

Port5 should be much better!

It's said that picture quality of port3 is not as good as of port5.

ElTopo

[kal]

You can read a summary of what to expect here:

http://www.curtpalme.com/Barco_Port3_Input.shtm

Sometimes port 5 is better, sometimes port 3. Depends on the model of projector. It's not black and white. There's no "one" answer.

Kal

[kal]

You can read a summary of what to expect here:

http://www.curtpalme.com/Barco_Port3_Input.shtm

Sometimes port 5 is better, sometimes port 3. Depends on the model of projector. It's not black and white. There's no "one" answer.

Kal

[RaWsHaRk]

on my 801s bd the port 3 is definitely better one.

[ElTopo]

I think beginning with BG808s port5 should be better.

ElTopo

[Ile]

808/1209 s-series projectors port3 is worse in all aspect. Colors, sharpness and ringing at higher resolutions.
In theory first stage are 500Mhz vs 5GHZ and second stage 200MHz vs 850MHz.
Port3 also goes through two more stages, 1GHZ and 850 MHz.
It's also use one sided through hole pcb, that is noisier than two sided smd board in port5.

In older sets there have been reported differences to both ways, even both inputs use similar differential design and same crappy switching/universal transistors for video. (BSX20 and 2N2905A)
Port3 signal way have one stage more, 2N2905A (200MHz).

Port3 have too much peaking, so with higher resolutions it looks worse because there is more ringing. With ES set this doesn't matter, because tubes can't focus to those high resolutions anyway.

At some point (could be related to s-series) they have been chanced port3 buffer transistors BSX20 (500MHz) to 2N2369A (675MHz). This little extra BW might help little, but next stage is still same crappy 200MHz so can't be huge difference.

[BASPARLEUR]

hi
it's right . but if we consider the bandwith of rgb output amplifier (120 mhz - 3 db ) , the interest of 5G bw is relative ! and what is the bw of your bd drive , or your scaler ?

however , rgb2 is particulary good for upgrade : we change all transistors and capacity . a new power supply , with very , very low noise increase dramatically the black level and the video noise ; the digital/analog converter ( moome v3 vith a new improved power or hd fury 4 ) is mechanical coupled with rgb2 for minimise lenght of analog video signal (we enter directly with hdmi on earth ) the signal is not routing on the frame . the end of this : port 5 is good , but vs a improved rgb2 , the result is really incredible , because the signal way is ultra short with only 3 stage when port 5 offer very long way and not necessary conversions at signal + very noisy supply + crossing frame signal !!!

you want more at: axel55@free.fr

sorry , i new in this forum and mp not active at this time .

best regards

[Ile]

5GHz is not ultimate goal for front end cards, higher you go more noise you get.
But original 200MHz transistors with too much peaking aren't good for 1080p/72Hz, it ring and is bit soft.

I chanced those to 1.2GHz video transistors in input and driver boards in my BG1200 and also removed some peaking. Much sharper result without ringing. Then I also chanced 180MHz end stages to neck boards, this gives also more sharpness. Then I cleaned power rails to minimize noise. I have also played with dvi and MP rgb pcb's in place of port3 board, but still you have to pass one original stage at switcher board that's not that great.

[BASPARLEUR]

hi ; you are right and you are experimented . it's a pleasure to converse with you . it's damage our respective location are so long ! it was interesting to compare we mods .
best

[Decibel]

I would to be a betatester!!!!!!!

muahahhahahahha

[Ile]

[Ile]

[gjaky]

Are 120MHz neck boards are using VPA06s or what? The NEC PG xtra neckboards have VPA13-s however it is "just" a 130MHz chip, but it can stand 120V supply compared to VPA18.

[barclay66]

Hi,

120MHz neck boards (like on the BG 1209s) use the VPH08. VCCmax of this part is 230V and it is specified for 80MHz. So I would assume they did some tweaking.

By the way:
The naming/numbering of the video packs says it all.
VPH -> High voltage, VPA -> Mid voltage.
Numbers indicate the bandwith: 06 -> 60MHz, 08 -> 80 MHz, 18 -> 180 MHz


Regards,
barclay66

[gjaky]

[barclay66]

[Ile]