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Re: Building 3BP1 tube NBTV Anderson monitor II

PostPosted: Fri Nov 11, 2016 9:38 am
by Harry Dalek
Great results Troy ! another Anderson monitor is born and yes good to name the monitor where it came from Steve's mind ,a lot of crap out there on the net ,least you know if Steve puts some thing up we can trust it will work after which you want after all the building.... reason i mentioned this when we you were thinking of starting this project .

I can See this will be a keeper as with mine and a useful tool for future projects again Great construction Troy and a really Quick Build too. :mrgreen:

Re: Building 3BP1 tube NBTV Anderson monitor II

PostPosted: Sat Nov 12, 2016 12:34 pm
by Steve Anderson
Good result there Troy, well done.

As I've mentioned before it can be adjusted to cater for other types of electrostatic CRTs. Those with a PDA (Post Deflection Accelerator) require a few kV from the power supply. Either an inverter or some form of voltage multiplier is required - the current requirement is small though. These CRTs usually have a side-contact near the faceplate/screen.

If you have a magnetically deflected and/or focused tube I suggest getting in contact with Klaas Robers as he has far more experience with those devices.

Steve A.

Re: Building 3BP1 tube NBTV Anderson monitor II

PostPosted: Mon Nov 14, 2016 12:17 am
by Panrock
Wow! That works really well. I'd like to add my congratulations too. :)

Steve O

Re: Building 3BP1 tube NBTV Anderson monitor II

PostPosted: Mon Nov 14, 2016 1:18 pm
by aussie_bloke
Thanks everyone for your positive comments, I am very glad the monitor is working good and will have so much fun with it! :)

I have now given the monitor that finishing touch of adding a front plate cover to give it that factory made look, I cut/grinded/drilled a piece of textured black scrap plastic to fit over the front and bolted it on and here is the finished product! :)

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For a bit of experimentation I thought I'd make the monitor look like it's displaying a colour picture, so to achieve this I convert a colour picture to it's red, green and blue primary colour B&W channels, display each channel on the monitor one after the other and take a photograph of each, then in Photoshop tint each pic to its primary colour and add them on top of each other which results in nice accurately reproduced colour image as seen! :)

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Lastly I showed my monitor to a veteran ham radio operator down the road from me who's teaching me ham radio and he was impressed and he gave me an ultra vintage 1940s/50s era Dumont 208-B oscilloscope which uses a larger 5BP1 tube, I fired it up and it is still working!!! :) As a future project I plan to restore it to perfectly functioning order and make it adaptable to be a video display without gutting the original oscilloscope electronics. But that's another story........ ;)
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Re: Building 3BP1 tube NBTV Anderson monitor II

PostPosted: Mon Nov 14, 2016 9:04 pm
by Steve Anderson
Very nice finishing which I tend to never get around to...

As for the vintage 5BPI 'scope, there's not a lot you need to do. It largely depends on what facilities it already has or doesn't. For NBTV ideally it would have an external X-input which is DC-coupled (most unlikely), a DC-coupled Y-input (normal vertical) and likewise a Z-input (brilliance - also most unlikely).

Depending on how original you wish to preserve the device these can be catered for. You'll also need a small NBTV 'adapter box' which would contain the NBTV-specifics, like ramp generators, sync separators etc...but that's all quite simple.

If you have model/make info I may have it already unless you have soft copies of the same.

Steve A.

Just noticed, Dumont 208-B...I'll have a dig...

No success on data for this, unless you don't mind parting with US$20-30...

Re: Building 3BP1 tube NBTV Anderson monitor II

PostPosted: Tue Nov 15, 2016 5:11 pm
by aussie_bloke

Re: Building 3BP1 tube NBTV Anderson monitor II

PostPosted: Wed Nov 16, 2016 8:19 pm
by Steve Anderson
Looking good Troy. I guess when I have the time I need to generate more test material, not just test-cards, but 'proper' videos. That requires me to complete the 625-32 converter. Though those with an Aurora converter could do it for you. Completion of the 625-32 converter is one of those things I hope by mid-December when I return home I'll be able to do.

Steve A.

Re: Building 3BP1 tube NBTV Anderson monitor II

PostPosted: Tue Dec 06, 2016 7:55 pm
by aussie_bloke
I thought I'd do an official off the screen video of my 3BP1 NBTV monitor displaying pictures for everyone's enjoyment, have chose to capture the screen using a vintage 1979 Hanimex VC600-P colour vidicon tube camera as the lag characteristics of the vidicon is perfect to compensate for much of the flicker and record a more viewable picture without frame breakup like on a CCD camera. Anyhow I've done a 12 min video compile of various test patterns, pictures and videos and webcam and uploaded it here on YouTube:

Re: Building 3BP1 tube NBTV Anderson monitor II

PostPosted: Thu Dec 08, 2016 8:10 pm
by Steve Anderson
Hi Troy, a generally good result in that video.

However, I'm wondering if you've got some hum in the deflection amp power supply which may explain the slightly uneven line-spacing. In some scenes it tends to stand still, in others it tends to wander usually to the left. This would probably be caused by the slight wandering of the phase difference between the 50Hz supply and the 12.5Hz NBTV frame rate.

If you have more than enough gain in the deflection amps it may be worth trying an additional stage of PSU filtering for just these circuits. Let me think on this a while...

Steve A.

Re: Building 3BP1 tube NBTV Anderson monitor II

PostPosted: Sun Jan 01, 2017 2:57 pm
by aussie_bloke
Happy new year NBTVers hope you all had a great one! :)

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Thought I'd display some new years graphics on my 3BP1 :) and those photos I actually shot on a vintage roll of Kodak Kodacolor X (expiry date 1972) which can be seen in full size on my Flickr page ... 8561896775 . I also took another photo on another roll of same vintage some weeks earlier:

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Thanks for pointing out some issues of my monitor Steve, I noticed the uneven spacing but didn't think too much of it as I didn't expect my monitor to be perfect, anyhow will experiment with additional filtering sometime down the track but for now am happy enough to play around with the monitor as it is despite the uneven spacing.

Some more news with the monitor, I decided to add sound so I bought a cheap $10 Jaycar 0.5W amp circuit kit and whacked it together and added an 8 ohm speaker and mounted it into a separate little plastic enclosure and so now I have picture and sound. Was going to place the speaker inside the monitor but decided against it for the obvious reason it magnetically affects the tube's beam. Anyhow here's a picture and a video:

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Re: Building 3BP1 tube NBTV Anderson monitor II

PostPosted: Sun Jan 01, 2017 4:09 pm
by Steve Anderson
Yep, speakers, transformers, anything with a magnetic field can (and usually will) upset a CRT. However, those used in multi-media/PC speakers are usually shielded to some extent. Those pulled from old CRT TVs/monitors will probably be shielded too.

Steve A.

Re: Building 3BP1 tube NBTV Anderson monitor II

PostPosted: Mon Jan 02, 2017 7:55 am
by Klaas Robers
It is quite simple.

Try to stick a screw driver to the magnet. If it is atracted the magnet is not shielded. If the screwdriver is (almost) not atracted by the "magnet" it is shielded. I also have a shielded loudspeaker built in my "Heathkit" SSTV monitor and I can't see any distortion in the scanned picture.

Re: Building 3BP1 tube NBTV Anderson monitor II

PostPosted: Mon Feb 06, 2017 12:43 am
by aussie_bloke
G'day all. I have been doing more colour photography experimentation with my Anderson II monitor using the method of displaying individual RGB channel images of a colour image, photographing each one onto B&W film and after scanning the film tinting each shot their respective primary colours and combining them to reconstruct the colour image. I have made some nice colour displays using ultra vintage 1946 expired Kodak Fluorographic 35mm green sensitive X-Ray film to capture the images on display and here they are below:
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The full sized images can be seen on my Flickr channel on this album page ... 9895959385

After showing Harry my colour experiments, he suggested I try seeing if I can make the green CRT produce a field/frame sequential colour image and suggested I stick red, green and blue filters in front of the screen to see if the luminance comes through the filters particularly the red filter. So I gave it a go using a lorikeet image as the test subject. I first stick the red filter in front of the screen displaying the red channel image, turning the monitor up till it almost clips I can see a dull red image, I took a snap of it with my camera phone. Then for the green, it made almost no difference obviously, so I photographed it without filter. Then placing the blue filter over the screen I could see a blue-green image, photographing it on the camera phone it looks green. In Photoshop I adjusted the lighting levels of each shot and added them together and the resultant image is a red-green colour picture due to the camera capturing the blue-green image as green. So I did a hue shift on that image and got a full RGB colour picture. :) . Here below are the images:
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I think it would be quite possible to at least make a green CRT into a 2 colour field sequential monitor using a red filter and a blue filter and having the red channel image outputting very bright and the blue-green channel image outputting at a lower light level to match the brightness of the red picture. The blue filter over the green screen will give the blue-green image and the red filter pretty much filters out all the green amazingly. Anyhow some food for thought on making a green CRT display a colour image using the colour wheel method.

Re: Building 3BP1 tube NBTV Anderson monitor II

PostPosted: Mon Feb 06, 2017 8:10 pm
by Harry Dalek
Yes Troy i am glad we had the chat about ,you have done a lot on colour wheels mechanical colour tv so you are the master of it here ...i have really only thought about it ! :roll:
The idea green phosphor CRT can be used with a colour wheel and display the other colours is pretty interesting ....and i would say you are the first to try it .
I will have to chat to you more as you have been able to do past colour experiments rather well and very simple .
This i understand is a photo at a time and over laying the images on the pc but i would think giving colour wheei a go now would be worth a shot ...and you would have your own colour tv system .
Heres a go at what it might look like with the limits of a animated gif

Re: Building 3BP1 tube NBTV Anderson monitor II

PostPosted: Tue Feb 07, 2017 5:59 am
by Klaas Robers
Yes, this looks interesting. But it would look as if you had a oscilloscope tube with a white phosphor that you could make RGB. This is not true, because white phosphor is not white phosphor, but a mixture of blue and yellow. These two colours together give an impression of white, but there is almost no red in it and almost no green. So an R-G-B colour wheel will give a very poor colour rendering, especially in red and green. People will alway show yellowish faces and skins.

Besides that the colour repetition frequency of about 4 Hz is far too low to give your eye a mixture impression of red, green and blue. The already enoying flicker of 12.5 Hz will be 3 times as enoying.