Scandoubler help

[Orjan]

I recently got an ACT MV1200 scandoubler ( http://www.amiga-hardware.com/mv1200.html ) but I am having trouble getting it to work as it should...

Before I got it, I always thought that scandoublers were plug ´n play, ie. plug it in, connect a VGA monitor, and it should work. But this doesn´t seem to be the case.. My monitor wont display anything when it is connected..

I have been told to select a VGA compatible screenmode ( Don´t know how to do this, by the way ) but I always thought that was for when you only had the 23->15 pin converter connected?

I tried to run a game ( NDOS ) with the scandoubler connected, but it wouldn´t show anything on the monitor then either.. Should it, or will it only work with Wb screens if I select a VGA compatible screenmode?

[Framiga]

VGA screen will be bypassed as is.

You have to chose a PAL or NTSC mode and check if your monitor, syncs from ~30Khz.

If your monitor start from 31.5Khz, you have to choose a NTSC mode.

[nex4060]

Have you set the jumpers corretly? you have to set it to scandouble mode and maybe try chainging the phase of the clock signal

[Orjan]

Well, thats the strange part... I have yet to find any jumpers...  :-?

[Darrin]

From the instructions, it looks like you'll have to open it up to find them.

I'd also test it with another monitor.  Find a really old crappy one and make sure you're using the correct screenmode.

[Orjan]

I have opened it up, I still can´t find any jumpers... And I have pictures to prove it... :-)

[Tempest]

@Orjan

I've got prove there are jumpers, look next to the VGA-out connector, there are two jumpers. (you've provided the evidence yourself, carefully examine the pictures in your first post in this thread :-D )

BTW I've got the same scandoubler/flickerfixer and it works well. My jumper configuration: enable = closed and phase = open (default configuration).

Hope this helps.

-Tempest

[Orjan]

Well, I´m beginning to doubt it is the Scandoubler I provided the link for... There seems to be a couple more with identical cases, except there are writing and stuff on them, which led me to believe it was the ACT one.. But mine doesn´t have any jumpers at all...  :-(

http://www.amiga-hardware.com/ezvga.html
http://www.amiga-hardware.com/scandoublerff.html
http://www.amiga-hardware.com/toastscan.html

At first I thought they were all clones and were basically identical, but mine doesn´t have any jumpers... It does have a hole in the case where the jumpers are supposed to be, and "Enable" and "Phase" etched into the case..  :-?

[Orjan]

I checked my monitor out, and the horizontal scan range is between 31 and 80 kHz.. Does anyone know what frequency the scandoubler puts out?

I tried turning the finetuning screw, but it didnt have any effect..

[Linchpin]

IIRC some scandoubler drop slightly lower and output @ 29-30khz, i remember mine takes a little while to warm up... :-)

[Orjan]

Ok... So if I leave it for a while and wait for it to get warm, it might go above 31kHz?

[golem]

I have had similar problems with a Eyetech EZ-view clip on chip scandoubler. Some Compaq/HP monitors just refuse to work with any modes. I currently use Phillps and have no problems with these monitors.

[Linchpin]

Hmm i dunno. Mines a DCE Scanmagic, i think its knackered :-)

Has been the victim of the soldering iron (I blame JurassicC) :-)

[zipper]

LinchpiN wrote:
IIRC some scandoubler drop slightly lower and output @ 29-30khz, i remember mine takes a little while to warm up... :-)

PAL 15.625 kHz makes doubled 31.250 kHz....?
And NTSC a bit more. The 31 kHz/50 Hz combination doesn't necessarily work with modern monitors, more Hz needed, so NTSC probably works with most monitors.