good oscilloscope for vector rescanning?

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nickciontea
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Post by nickciontea » Tue Oct 15, 2013 12:31 pm

smaller size doesn't really exist.

They are all going to be 14-16" deep. I do have 2 monitors with smaller screens 3x3.. then 3 monitors that seem to 3x5 and 2 monitors at 6x4.

all sizes approximated. but all relatively housed the same.

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daverj
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Post by daverj » Tue Oct 15, 2013 4:07 pm

Those type of CRTs have internal deflection plates inside the tubes rather than external coils around the tubes, like a TV had. So they can't make a shallow version of that CRT.

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Post by nickciontea » Tue Oct 15, 2013 8:36 pm

Image

this is the smallest i have. Kikusiu

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Post by mr_capstick » Thu Oct 24, 2013 5:50 pm

In all the time I've been looking at this thread the consensus seems to be that the Leader LBO-51MA and the Tektronix 608 are the 2 that will work with few problems. Both of these I've found near impossible to find in the UK which means importing and using a transformer. If anyone's found a UK equivalent I'd love to hear about it?

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Post by daverj » Fri Oct 25, 2013 1:32 pm

I am not 100% sure, but I think the line voltage on the 608 is selected with an internal jumper block. But the power cable would also have to be replaced. You might contact Tektronix to double check that. There's probably a UK Tektronix office that would know.

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Post by i.m.klif » Sat Oct 26, 2013 7:05 am

Some Leader units also have selectable voltage.

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raulsworldofsynths
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Post by raulsworldofsynths » Fri Nov 01, 2013 2:55 pm

Just a quick add to this thread because I hadn't seen it mentioned.
When you patch video into the scope is it straight out of the VSG? Unamplified? Or does adding gain via the voltage bridge more visible on the scope. Still experimenting with Dave's handy patch possibilities sheet via the horizontal,vertical and video inputs.

I'm using the leader LBO 51MA.

Thanks all.

Raul

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SCOPES IN UK OR EUROPE FOR VECTOR SCANNING

Post by engi » Tue Nov 05, 2013 11:03 pm

Hello I was also wandering if anyone might know of a scope available in the Uk or europe. that might be minimal effort to get working with lzx. The shipping/duty and power conversion on the leader adds up to a lot of money. If anyone could help it would be appreciated.

Also is it vital having a VBM.

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Post by Arturo00 » Mon Nov 11, 2013 4:16 pm

G'day all.

I just wanted to give everyone a fair warning that all LBO-51MAs being sold by the eBay seller Esssurplus have burn in marks on the CRT display.

I recently purchased a unit from them and it had the burn in marks. I opened a case and they offered to look for a unit with a clean display. They told me that they had found a clean one, and when I asked them to verify with a picture (with the grid frame removed), they seemed a little hesitant. When they did remove the grid, they discovered that it did in fact have burn in marks on the CRT. Long story short, they said that they would check all their remaining units by removing the grid to see if there were any with clean displays. I just heard back from this seller and they were unable to find one without burn in marks.

That being said, purchase this item from this seller at your own risk. They aren't bad sellers, in fact, they were quite cooperative, but as of today, NONE of the LBO-51MAs that they have in their stock is blotch free.


ps. they will be giving me a refund and I get to keep the display.
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raulsworldofsynths
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Post by raulsworldofsynths » Mon Nov 11, 2013 4:26 pm

I recently bought 3 from them. At $49.99
Two have minor burn marks around the center and the third worked out to be fairly clean.
The fact that the items work for me was great in contrast to a couple of other sellers with shady return policies and poor communication.
At $49.99 I think they surpassed my expectations and gave me a working device at a reasonable price.
For $50 I didn't expect perfection.
There's some amount of work they had to do on their end for listing and shipping the items. And they were decent people over email.

For what it's worth.

Raul

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Post by Arturo00 » Mon Jan 27, 2014 6:24 pm

I'm pleased to announce that my search for the perfect vector monitor is finally over...hopefully. After going through a Tektronix 475, 608 and two LBO-51MAs, I've finally scored a Tektronix 620!

The image is crisp and clean and there are no burn marks or blemishes on the CRT. Only issue is that the image doesn't completely fill the screen. All the other montors I own have X/Y gain on the front panel, this one seems to be missing this control. Anyone familiar with the 620 know where I might find the X/Y gain controls? I haven't opened it up yet. Hoping someone might point me in the right direction.

Thanks!


ps. This is the auction I bought mine from. There are two left.

Also, in the interest of adding to the list of vector monitors that can be used for vector rescanning, the LBO-51MA was released under another name: Dunegan Model 118A. Unfortunately it looks like they might also suffer from the same burn in situation as the LBO-51MAs do, so purchase with caution.

Also also, stumbled upon this guy during my travels: Hitachi VS-025. Cannot vouch for it, but it looks promising.

Enjoy!
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RCA WO-91A

Post by fuckthisregistration » Sun Feb 16, 2014 6:03 pm

I have this oscilloscope, seems perfect for the job. Seems I have to amplify the video signal, as the "Z" input requires 12v rms p2p. From what I've read this isn't a composite video signal? Where/how would I get the proper 'video' signal if I'm using a ccd composite video camera?

From the manual:
"NEW FEATURE
This RCA WO-91A incorporates a 2 stage sync separator which provides solid sync action on composite tv signals.
The Separator is automatically connected in the TV "V" and "H" preset sweep positions. When using thsese preset positions for observation of composite TV signals, set the SYNC-H SEL switch to "INT -", and set V POLARITY switch to the position in which the sync pulses in the composite TV signal extend downward, as shown in figures 4 and 5 on page 12 of the instruction book.

Starting in the TV "H" position, set SYNC ADJ about 1/3rd from fully counter clockwise and adjust SWEEP VERNIER for two "H" patterns. Switch to the TV "V" position: If the "V" patterns do not lock in, adjust R-90 to obtain 2 patterns. (R-90 is acessable through the front hole on the right hand side of the case)."

Dated 3/61
This is a tube unit, in seemingly good working condition. I have the manual, went through operation and calibration procedures, and all seems well. I have had a hard time (probably from lack of experience) viewing the sync pulses from my composite signal, but other than that all good.

Correct me if I'm wrong, but I should be able to do vector rescanning by setting internal sync sweep to TV "H", applying a 30/60 hz signal to the vertical amp, and a video signal amplified to 12v p2p to the Z input. I'm just not sure what 'type' of video signal I need.
Thanks in advance!!!
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RCA WO-91A #2

Post by fuckthisregistration » Sun Feb 16, 2014 6:13 pm

Also, I don't have the original probe, not sure if it's necessary (and I've never been able to find one) Type number WG-300B or for RF From 500 Kc(KHz) to 250 Mc(MHz) Type No. WG-302A.

If anyone knows how to "tune" these up. I'm assuming it at least needs some of the 50 year old caps replaced. The screen could be brighter too, can I bring up the gain of the CRT?

Oh, and sorry about my username.... It took like 10 tries to get the registration to go through, and it just so happened to work on that one.

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Post by nickciontea » Fri Feb 21, 2014 11:09 am

Arturo00 wrote:I'm pleased to announce that my search for the perfect vector monitor is finally over...hopefully. After going through a Tektronix 475, 608 and two LBO-51MAs, I've finally scored a Tektronix 620!

The image is crisp and clean and there are no burn marks or blemishes on the CRT. Only issue is that the image doesn't completely fill the screen. All the other montors I own have X/Y gain on the front panel, this one seems to be missing this control. Anyone familiar with the 620 know where I might find the X/Y gain controls? I haven't opened it up yet. Hoping someone might point me in the right direction.

Thanks!
Don't open it up.. not worth it..
You can do this on the synth side.. All you are doing is inputting a different amplitude ramp.. So if you scale down your ramps. the screen is smaller.. if you amplify your ramps by a value greater than 1. You get a bigger screen.. Try sending the ramps thru the voltage bridge to amp them up.. then thru an attenuator to control the size.

cheers

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Post by Arturo00 » Fri Feb 21, 2014 2:44 pm

nickciontea wrote:Don't open it up.. not worth it..
You can do this on the synth side.. All you are doing is inputting a different amplitude ramp.. So if you scale down your ramps. the screen is smaller.. if you amplify your ramps by a value greater than 1. You get a bigger screen.. Try sending the ramps thru the voltage bridge to amp them up.. then thru an attenuator to control the size.

cheers
Good call. Though I did find the X and Y gains, I have yet to make the adjustment.
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nickciontea
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Post by nickciontea » Fri Feb 21, 2014 7:20 pm

its also good to not fill the screen. This will cause certain displacements to go "off screen" , but I'm sure you understand that!

I always found the 620 to be scaled pretty nicely.

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Post by giantmecha » Fri Feb 28, 2014 3:01 am

Not sure if you guys have seen the newest Clark video, but it's some serious oscilloscope insanity: http://adoxo.co/post/77911990788/clark-superscope

:sb:

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Post by Arturo00 » Fri Feb 28, 2014 11:37 am

giantmecha
Nice! Some very cool patterns in there.

Those were Lissajous patterns using the X-Y inputs on a standard scope. Some of my earliest experiments with images on oscilloscopes was with Lissajous patterns using a SynthTech E350. They're so much fun to play with! Would this still be considered Vector Rescanning?
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Post by nickciontea » Fri Feb 28, 2014 12:55 pm

Arturo00 wrote:giantmecha
Those were Lissajous patterns using the X-Y inputs on a standard scope. Some of my earliest experiments with images on oscilloscopes was with Lissajous patterns using a SynthTech E350. They're so much fun to play with! Would this still be considered Vector Rescanning?
yes they are vectors. and they are being rescanned. .That's a pretty vague term. I'm no expert. but scan processing may be more of a "video rate" term. But its all hogwash anyways. we call things rutt-etra.. but what we do is not rutt etra either.. RE was an instrument. just like the Scanimate.

you could make some vectors in Illustrator and shoot it off you computer screen and call it vector rescanning. these terms mean nothing to ppl outside our circle.. Just try to come up with the longest most complex Buchla-ish name you can. :nana: :nana:

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Post by sync24 » Mon Feb 08, 2016 3:40 pm

hello, great info here and I just managed to pick up a broken Tektronix 608, it looks like it's been dropped but still powers up... just no dot on the screen.
I've taken it to my tech dude but he doesn't have a schematic, anyone got access to a pdf they'd care to share?
Cheers!

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Post by cannonball swandive » Sat Jul 02, 2016 8:33 am

I have an older scope with XYZ inputs. I love watching my oscillators using the xy inputs. How do I go about incorporating video images into the z input?

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Post by nickciontea » Sun Jul 03, 2016 8:00 pm

You'll need to try and verify the voltage your scope wants on Z. and scale accordingly.

You'll also want to verify the bandwidth of the input.

Then take the video luma signal from VSG or cortex and send that out to the z input. remember this will come through as 0-1v

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Post by arbito » Mon Sep 05, 2016 3:07 pm

I took a chance on a $50 Leader LBO-51MA ( not something I normally do ). It powers on but I can't produce a visual signal. Before I chalk this up as a broken tube, anything I should test first before I repair or donate? This is my first oscilloscope so I definitely could be doing something wrong.

I'm using Rca bnc adapters to mono rca/3.5mm cables on the x y and z. Tried connecting straight from waveforms on the prismatic ray.

Any advice is much appreciated.

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Post by nerdware » Mon Sep 05, 2016 4:46 pm

Is there a brightness control? Perhaps its set too low. I've had an anxious moment or two like that with my Gould scope, but it was always just the brightness setting.

I actually had a moment like this with my first PR - it took me way too long to realise I had to turn up the gain controls before the LED came on. :doh:
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Post by arbito » Mon Sep 05, 2016 5:12 pm

I adjusted the gain, also has tilt & astig adjustments. No dice... :(

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