Trying to hook up Dreamcast to Hantarex (sync problem)

[dennis808]

Hello all, a longtime forum lurker here in serious need of some tehnical advice...

Im trying to hook up a Hanterex MTC21EQ monitor to my consoles Dreamcast.
I believe this is a type of monitor that has been used in surveillance, editing, or point-of-purchase environments, since it sports a wealth of options on the back as you can see in this pic:


and a close-up:


I mainly bought this monitor to replace the old Mitsubishi TV which I have in my cabinet right now.
Here's a pic of the Mitsubishi TV hooked up to a Dreamcast with a RGB-SCART cable:


Since the Hantarex also has a SCART socket (which accepts RGB signal) I thought it would be an easy swap. But the only picture I'm getting (even after adjusting all of the pots) is this:


Even after pushing and tweaking every button the picture remains really sharp, but completely scrambled

Both the Dreamcast and my Playstation2 give these type of images when I connect them via RGB-SCART cables.
When I connect the consoles via composite (the yellow RCA plug) I get a stable image, but without the nice quality of an RGB connection:


What REALLY confused me is that when I hook up my DVD-player via RGB-SCART, it gives me a stable and clear picture ???


I assume this is a sync issue.
Probably the RGB-HV above the SCART socket means this monitor only accepts seperate horizontal and vertical sync.
Is it possible to make the Dreamcst output this type of signal by hacking a SCART-cable or a Dreamcast VGA-box?
Or do i need to use something like the Ultimarc J-PAC to seperate the sync-signals?
Please someone help me so I can use this Hantarex in it's full RGB glory...

[antron]

Probably the RGB-HV above the SCART socket means this monitor only accepts seperate horizontal and vertical sync.

on the scart it takes c-vid and makes whatever sync it needs. that's how it's supposed to work anyway, and probably is with your cable box.

Is it possible to make the Dreamcst output this type of signal by hacking a SCART-cable or a Dreamcast VGA-box?

Dreamcast does have separate syncs already, if you want to make your own cable.
that won't help with the PS2 though, it only has c-vid.

and you tried the analog/TTL, sync +/-, 75ohm termination, H-phase, vert freq, etc?

[viletim]

dennis808,

All you need to do is adjust the Horizontal Phase (aka Horizontal Hold). It looks like there's a potentiometer next to the SCART socket...

[neorichieb1971]

I have the exact same problem with mine.

I put composite or svideo in and the picture is fine, use the scart connection and its a load of shite. (Same as pic above).

I had Fire-bug come round and try reconfiguring the scart leads for ages but it never worked no matter what we did.

An interesting observation on mine was that with an NTSC machine it sync'd at 50hz via SCART and created all the symptoms above. I borrowed someones PAL machine which is 50hz and it still looked exactly the same.

If you search Hantarex in hardware i'm sure you will find my original thread.

[dennis808]

Thank you all for yor fast replies

I adjusted every possible knob, switch and dial on this monitor, using 50 & 60 Hz games, but the picture stayed the same

When you say the Dreamcast already outputs separate sync, do you mean from the SCART end of the AV-cable, or from the AV multi port on the console itself?
I am under the impression that the SCART socket is able to receive both composite sync as HV sync, and that most TV's are wired for composite.
It still strikes me as odd that my simple DVD-player outputs fine on both my TV as the Hantarex. :s

Bottomline: would it be possible to rewire a Dreamcast AV-cable so that it feeds a separated sync signal to the Hantarex's SCART socket?

[DC906270]

here is a link to the Dreamcast av pinout :

http://www.gamesx.com/wiki/doku.php?id=av:dreamcastav

it looks like it has seperate pin for H + V sync as well as composite sync, so you may be able to make a cable that works with your RGBHV monitor

whether the separate sync pins are still active when in non-VGA 15kHZ mode, is another matter

[gray117]

I must first admit I do not know the specifics of your monitor... but ...

The dreamcast will only output hv when in vga mode @ 31 khz...

Most of the time scart will only work for low resolution 15khz signals which I assume is the case here [... however there is an extreme outside chance that maybe on this piece of kit it is simply a 'plug' so could accept 15khz/31khz]

I assume, however, what you're wanting is to feed the monitor a 15khz low res signal and therefore split the HV syncs from the rgbs.

*editted for silly mistake

A [expensive] cable like a keene syncblaster to do the job to split it out the scart rgbs to a vga connection rgbhv - providing a vga plug on the end. Now the keene cable is expensive, and most cheap scart>vga cables obviously do not actually split the hv syncs. However I have noticed some cheap ones on ebay that state they do split the syncs...

http://cgi.ebay.co.uk/2M-SCART-LEAD-TO- ... 675wt_1002

^anyone tried these, they seem great if they do what they say on the description?

Anyways either of these cables gives you a 15khz rgbhv signal in the same kind of pinout as an normal vga plug which I'm presuming does not work on the vga port of this monitor unless it is simply a 'plug' which can adapt to 15khz as opposed to typical 31khz [unlikely... since it would make a rgbhv scart socket kind of redundant in the first place]

Your problem now is to get the vga plug into the scart socket... You need to know what pins this scart socket is expecting to receive the rgbhv signals [and possibly a gound signal too - sometimes very important - some kits sometimes need a ground per rgb signal .. some just a common one...]

You could simply try your luck with and connect the vga to another cable such as a cheap scart to vga cable (the problem here is that often not all the vga pins are wired to all the scart ones even IF they are aligned properly...)

What you will probably have to resort to is breaking down and constructing a cable that met the pinouts from vga to scart in the manner your monitor wants...

[gray117]

What REALLY confused me is that when I hook up my DVD-player via RGB-SCART, it gives me a stable and clear picture ???

Scart sockets can also often accept composite video - some even do component with sync on green pin ... in fact some cheap scart cables are often wired for composite video rather than proper rgb ... I suspect your dvd player is coming in as composite video... ?