Compact Drum Monitor

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Postby Jean-luc » Mon May 23, 2011 7:32 am

Congratulations Holtzman, this is a wonderfull monitor, I am very impressed with such perfection!
NBTV video with two colors soon ?

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Postby holtzman » Mon May 23, 2011 8:49 am

Thanks for your warm feedback!
Now I'm building the "body", to shield from dust. Hope it will look good, too. You know, it always hurts to put something technical in a "box".
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Re: Thanks

Postby gary » Mon May 23, 2011 11:21 am

holtzman wrote:You know, it always hurts to put something technical in a "box".

Indeed it is, especially with your exceptional constructions skills, how about building an acrylic (perspex) box - there is at least a 30's precedent: ... antom.html

You could then call your project the Holtzman CDM-1 Phantom Televisor! ;-)

(CDM = Compact Drum Monitor)

Edit: The only problem is they wanted their "Phantom" to look futuristic whereas we generally want it to look "retro" - oh well... ;-)

Postby Lawnboy » Mon May 23, 2011 1:57 pm

wow that is very impressive. excellent work!
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Postby Harry Dalek » Wed May 25, 2011 5:33 pm

Sorry taken this long for my internet to speed up again so at last got to view your utube video.

Thats really impressive and inspirational ...Dam thats a good looking hot rod!
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Postby Klaas Robers » Thu May 26, 2011 2:50 am

I suddenly realized myself that this two drum slit monitor can synchronise line and frame separatedly. With the normal disc or drum monitor you have to slip frames vertically to synchronize horizontally. In your short film I saw the frame sync (horizontally) acting as a separate process, with sometimes seeing (part of) a line that should be at the right edge appearing at the left. This happens too with a disc monitor, but not while the picture is kept in sync in the vertical (line) direction. As long as in the video signal the line number is kept constant.

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Postby holtzman » Thu May 26, 2011 6:33 pm

Thanks for everybody's input!

Gary, yes it's impressive to make a clear cabinet but, first, I have no acryl cutting & thermal bending tools, second, all the opto-forks work with visible light and it works better in the darkness inside the box.

Klaas, I disagree with you that there is separate horizontal sync which can be seen. Yes you can see some spare lines from both sides, what does not happen with disc. But right now, the sync between 2 drums is deadly locked from the start, the stepper motor is "geared" to the main drum by constant ratio 1:12. I could make stepper body rotatable, thus making possible to adjust picture to the frame instead of slipping frames vertically, but it would be just more complex.

Here is a non-finished cabinet made of foamed PVC sheets. I converted the exact shape of flat parts by my software from the 3D model, so it went quite fast.
IMG_0102.jpg (105.16 KiB) Viewed 4902 times
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