Yes, that is possible!

Many (although not all) of these monitors have a 9-pin port often labeled "TTL" or something. You can connect CGA and EGA cards directly to those.

As for VGA, that can be made to work with RGB SCART monitors and TVs as well, but it will require a scan doubler an active adapter.

However, some VGA cards can be programmed to directly output the lower 15kHz frequency supported by these monitors, without needing a scan doubler an active adapter. In that case, a passive VGA to RGB SCART cable would suffice. (Well, that and the software to switch the VGA card in the required mode.)

If you search a bit on this forum, and google (or DuckDuckGo) a bit on-line for keywords like "VGA", "RGB SCART", and "scan doubler", you'll find plenty of information.

These are always fun projects. Good luck and have fun! 😃

Also kudos for fixing those CRTs. They're all getting rarer these days.

EDIT: sorry, I indeed got it the other way around by erroneously mentioning a scan doubler as a solution. Thanks, Grzyb.

digger wrote on 2022-02-04, 23:27:

As for VGA, that can be made to work with RGB SCART monitors and TVs as well, but it will require a scan doubler.

What?
Scan doubler is used to connect a 15 kHz HSYNC video source to VGA monitor ie. 31 kHz.
The other way around would be "scan halfer" - and yes, such devices do exist, see eg. Creative TV Coder, but the resulting image quality isn't good enough to replace a VGA monitor.

Grzyb wrote on 2022-02-05, 00:51:

What? Scan doubler is used to connect a 15 kHz HSYNC video source to VGA monitor ie. 31 kHz. The other way around would be "scan […]
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digger wrote on 2022-02-04, 23:27:

As for VGA, that can be made to work with RGB SCART monitors and TVs as well, but it will require a scan doubler.

What?
Scan doubler is used to connect a 15 kHz HSYNC video source to VGA monitor ie. 31 kHz.
The other way around would be "scan halfer" - and yes, such devices do exist, see eg. Creative TV Coder, but the resulting image quality isn't good enough to replace a VGA monitor.

The above isn’t always accurate

A 15KHZ RGBS Analog Monitor Such as an Amiga would run is most definitely just as capable as an older smaller VGA monitor.

Run off a scan converter through RGB+ Sync to a Targa / Amiga compatible screen just lowers the refresh but the image remains crystal clear , one of my late 13” Magnavox multi standard 15khz CGA + Analog screens has a .28 dot pitch just like a decent VGA.

It's not just dot pitch, it's also refresh rate and interlace.
VGA can do 480 lines at 60 Hz, and 400 lines at 70 Hz, all NON-interlaced.
15 kHz means about 400 lines at 60 Hz (NTSC), or 480 lines at 50 Hz (PAL), all interlaced.

I live in a PAL country, and I've found the 50 Hz of Amiga color monitor to be painful, even in non-interlaced low-res modes...
50 Hz may be enough with long afterglow green phosphor, see eg. IBM 5151, but not in color monitors.

crt vga are just hard to find ! i bought 2 sony trinitrons 14 inch off markplaats it was a scam seller deleted his acount

would something like this work https://www.ebay.nl/itm/114363618169

scroeffie wrote on 2022-02-09, 08:14:

would something like this work https://www.ebay.nl/itm/114363618169

Seems OK.
But seriously, don't expect too much.
Such stuff may be enough for 320x200 games, but not for 80x25 text.

I can't believe you can't find a CRT VGA monitor...
Anyway, while LCD monitors aren't perfect for old VGA cards, they are still better than 15 kHz ones.

I've run VGA to a 1084S in the past using a CL5428/9 card and Tomi Engdahl's vgatotv hookups and drivers. Worked pretty well for DOS games but DOS text was pretty squirmy, but readable. Also tried windows output from a Geforce 3 ViVo card to an older composite only one (1071?) but although games etc looked okayish on it, desktop was too fuzzy to make out well, couldn't go below 800x600 res for some reason.

However, the "almost native" way to use these is CGA with a real CGA card, preferably with a composite out, then you get the artifact color modes. But you would want to be doing that on a turbo XT to low end 386 for the games that like it.

edit: Tomi Engdahls stuff... https://www.epanorama.net/circuits/vga2tv/cindex.html

got ripped of on marktplaats bought 2 of these Sony Trinitron VGA CRT scherm 14

BitWrangler wrote on 2022-02-09, 15:17:

However, the "almost native" way to use these is CGA with a real CGA card, preferably with a composite out, then you get the artifact color modes.

CGA composite output is NTSC, monitors for the European market were PAL, so no color at all here...

Derp... and living both sides of the pond, you'd think I'd remember that. Possibly my brain got broke for that when NTSC mode on my A1200 worked fine on my 1084s and Hitachi Monitor-TV ... meaning maybe it does NTSC frame timing but PAL color encoding and led me astray.