Fudoh's ode to old display technology

[hakujin]

On a properly configured BVM set, is there any advantage to RGB over component for inputs?

[NWrain]

RGB is better because it has more color channels, 3 to Component's 2. In practice it is difficult to see a difference between RGB and Component. I would use RGB before transcoding it into Component.

[firebird]

Hello!

I'm trying to configure my new BVM 20F1E properly as I'm not happy with the picture "look" at the moment. During transport it got a a bit damaged, but I'm not sure if it is just on the outside or not...

Setup:

I'm using a sigma raijin's RGB output incl sync, going directly to the four BNC connections on "slot 6" (INPUT NO 123) of the BVM.

At the moment I'm using
BRIGHTNESS 0841
CONTRAST 0431

COLOR TEMP: STD: GAINS: RGB: 0850 0850 0850

The picture appears to be too "white", no matter how I adjust color temp (gains), contrast and brightness. Bright colours appear to be almost white, and it is hard to distinguish them from white.
I am not able to adjust any "phase" or "chroma", I guess this is not applicable for the RGB signal. Taking a picture is difficult, but anyhow, here is one:


The picture is kind of sharper than it would be on my candycab, though the colours are much more nicer on the candycab. The experience is way better sort of speak...

Those of you with BVM, do you have any ideas for tuning the picture? Do you have any favorite settings?

Thanks,
-firebird

[kamiboy]

Sounds like a resistance issue. 75 ohm vs 220 ohm or some such.

[lettuce]

Doesnt the BVM need BNC terminators on the unused BNC sockets??

I had a similar situations to yours on my PVM but in reverse (didnt appear to be getting enough contrast to the screen) a complete factory restore seems to help out, maybe try the same on the BVM?

[firebird]

Thanks for the tip. Did some further research and found... :



Those terminators might indeed be useful! I will get a hold of these asap and let you know the result.

-firebird

[lettuce]

Ah thats good, i claim to be no expert just recycling the information thats been passed on to me

Where you based?, i got a set of 4 off eBay for like £3.40 delivered!

[STG]

The picture appears to be too "white", no matter how I adjust color temp (gains), contrast and brightness. Bright colours appear to be almost white, and it is hard to distinguish them from white.

I posted about this here: http://shmups.system11.org/viewtopic.ph ... 79#p865379

An Extron unit like this will tone down the overly bright image you're getting.

[firebird]

Thanks a lot for your help and link! (I placed an order )

I'm also relieved that the monitor seems to be intact after all, and that the problem can be fixed.

-firebird

[STG]

No problem!

Yep, nothing wrong with your monitor, had the exact same issue with my supergun setup as well! I would have tried using terminators as well like lettuce recommended but I didn't have enough on-hand for each empty socket, and ultimately I found that I didn't need them.

[Fudoh]

Terminating the outputs won't help much. An external sync processor like the Extron will try to normalize the RGB levels, but you can do this without an additional machine by just adding variable resistors to your RGB lines. Just a few cents and very easy to do. Without them you're right now running up to 2.5V into the RGB lines, while consumer RGB is spec'ed at 0.7V peak voltage.

[Ed Oscuro]

damnit, knew I should've mentioned resistors on the RGB lines earlier

[STG]

Terminating the outputs won't help much.

Oh whoops, I should have clarified that part better in my reply, sorry about that! It was a separate thought, I just found the need for using terminators on this monitor unnecessary, and that wouldn't fix the brightness issue above.

[SharkSkin-Man]

Have you adjusted the brightness pot on the rear of the Raijin?

[firebird]

Brightness control on the Raijin only applies to the V.S.VHS output, so it does not do anything.

I believe 5k Ohm or 1k Ohm pot meters should do the job. Or maybe I just wait for the Extron (I assume it doesn't introduce any lag of any sort)

-firebird

[SharkSkin-Man]

Brightness control on the Raijin only applies to the V.S.VHS output, so it does not do anything.

Damn, that's a bit of a weird design choice - the Sigma AV7000 brightness control works on RGB too.

[fagin]

Firebird,
Once you have installed some resistance on your RGB lines, can you please sort our the convergence issue you have as well. It's making my eyes bleed!

[SharkSkin-Man]

When using a good quality CRT (PVM etc.) how much jitter, if any, would one expect to see on a 240p image?
I was correcting the geometry on mine, so I was right up close to the screen, and noticed a certain amount of E/W jitter along the edges of vertical lines (not visible from my normal viewing position).

My OCD side now wants to know if this is normal, or something 'wrong' that I can correct.

I've gone from having a small amount of jitter, to jitter all over the image along with wavy/wobbly interference. Happens with all sources I've tested (and tested working fine on another display).

Bad caps or something maybe?

[firebird]

@SharkSkin-Man, I had some disturbance/noisy picture due to a faulty connection on one my scart contacts. Check pinouts and connections?

@fagin, screen looking much nicer now. Most convergence is gone, and I hope your eyes don't bleed

[SharkSkin-Man]

I've got two different scart -> BNC cables and the interference is present with both, as well as with various different sources.

It's just an old screen that probably saw a lot of use in the studio it was pulled from.

[kamiboy]

These sneaky studios are selling us poor CRT connoisseurs queer giraffes in bulk.

It is tempting to save a few hundred and go for the studio end-of-service units with over 50.000 hours on them but I say a good CRT should be an investment in the future. Pay large a sum once for a NIB or mint unit whose history and hours you know and save yourself money and future troubles.

Fixing a dying CRT is often not as straightforward as fixing a dying console unfortunately.

If I could lay my hands on a lightly used 20" BVM for a few thousand I would do it.

[SharkSkin-Man]

Well, this one was only £50 - I guess it was a punt worth taking at the time. It's still useable until I can raise some spare cash to try out the XRGB-Mini.

[Lawfer]

Is there any such thing as a 31Khz Broadcat Monitor?

[NWrain]

There is the BVM D series, and BVM A series. The PVM 20L5 is also a popular model.

[Lawfer]

There is the BVM D series, and BVM A series. The PVM 20L5 is also a popular model.

Thanks, but are any of these SDTV/EDTV? From what I can tell, these monitors all can do 720p, 1080i etc.

[Ed Oscuro]

That might need a special SDI card - don't know about Sony's actual offerings but apparently a third party made both SD and HD input options for the 20L5. (Also note they mention a JVC monitor, although it's not clear if it actually had 31KHz support...maybe somebody can fill in, currently I'm not sure if 15KHz supports resolutions much higher than 300 TVL.)

Anyway I would just use a 31KHz PC VGA monitor and save hours on the expensive CRT.

[Lawfer]

That might need a special SDI card - don't know about Sony's actual offerings but apparently a third party made both SD and HD input options for the 20L5.

Anyway I would just use a 31KHz PC VGA monitor and save hours on the expensive CRT.

Blasphemy, PC monitors are for PC, not for consoles! I need a monitor with rectangular pixels, 720x480 max resolution, square shaped 4x3 aspect ratio, 31Khz and damn is something like that hard to find, there are tons of 15.734kHz monitors that fits those criterias though.

[cyborc]

I have a 20L5. It can do 480p via component, I tested it with my ps2.

I've heard it can do also do 480p through VGA (dreamcast) as well but I haven't tried it yet.

[Lawfer]

I have a 20L5. It can do 480p via component, I tested it with my ps2.

I've heard it can do also do 480p through VGA (dreamcast) as well but I haven't tried it yet.

Yeah but it is HD, I want a non-HD one.

[Fudoh]

Yeah but it is HD, I want a non-HD one.

it doesn't make a difference. The 15khz-only 20" BVMs use the very same tube, same 800-1000TVL resolution (depending on the specific) model. Why do think it matters ?