Your vote please...

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martin martin

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Apr 24, 2022, 10:11:32 AMApr 24
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Greetings all.
I was given this RCA possible trainer scope.  Date unknown.  
  • Restore to its full glory?
  • Sell on the Bay
  • Turn into a scope clock?  

I have no idea if it's electrostatic or magnetic deflection and I have very little experience in tube repairs.

Your vote please!
RCA.jpg

Bogdan Catrinoiu

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Apr 24, 2022, 10:16:16 AMApr 24
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Scope clock :) 
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<RCA.jpg>

Toby Thain

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Apr 24, 2022, 10:17:37 AMApr 24
to neoni...@googlegroups.com, martin martin
On 2022-04-24 10:11 a.m., martin martin wrote:
> Greetings all.
> I was given this RCA possible trainer scope.  Date unknown.
>
> * Restore to its full glory?
> * Sell on the Bay
> * Turn into a scope clock?
>

Vote: Restore

>
> I have no idea if it's electrostatic or magnetic deflection and I have
> very little experience in tube repairs.
>
> Your vote please!
>
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bogdanp...@yahoo.com

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Apr 24, 2022, 10:49:57 AMApr 24
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Clock

Sent from my iPhone

> On 24 Apr 2022, at 17:24, Toby Thain <to...@telegraphics.com.au> wrote:
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Adrian Pardini

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Apr 24, 2022, 10:59:49 AMApr 24
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Restore, then turn it into a clock (I'm thinking of something like Oscistudio)

In any case, I'll support whatever you decide to do if we all get to
see it here :)

Regards
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Adrián Pardini

Adrian Godwin

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Apr 24, 2022, 11:50:23 AMApr 24
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On Sun, Apr 24, 2022 at 3:59 PM Adrian Pardini <pardo...@gmail.com> wrote:
> Restore, then turn it into a clock (I'm thinking of something like Oscistudio)

Seconded. It would be good to have it fully working but you'll never use it. Maybe add a PIR-based auto shutoff as was described here recently to preserve the tube life.

 

John Rehwinkel

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Apr 24, 2022, 11:54:29 AMApr 24
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I was given this RCA possible trainer scope.  Date unknown.  
  • Restore to its full glory?
  • Sell on the Bay
  • Turn into a scope clock?  

I have no idea if it's electrostatic or magnetic deflection and I have very little experience in tube repairs.

It's very likely electrostatic deflection.  Magnetic deflection scopes are unusual.

To give myself something to do during the lockdown, I restored my pile of broken scopes, only to realize I now have a pile of working,
but hopelessly obsolete scopes.  I have no particular interest in clocks, so I'm turning them into steampunk art projects that display
interesting things on their screens, with the various controls affecting the display in different ways.

- John

Mac Doktor

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Apr 24, 2022, 5:28:50 PMApr 24
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On Apr 24, 2022, at 11:54 AM, 'John Rehwinkel' via neonixie-l <neoni...@googlegroups.com> wrote:

To give myself something to do during the lockdown, I restored my pile of broken scopes, only to realize I now have a pile of working,
but hopelessly obsolete scopes.  

Do you want to part with one of the larger scopes? High bandwidth isn't an issue here but I do need an X/Y display. Scope clock kits are out of my price range. I simply don't want one bad enough.


I have no particular interest in clocks, so I'm turning them into steampunk art projects that display
interesting things on their screens, with the various controls affecting the display in different ways.

I'm fascinated this kind of thing and would love to hear more. Have you seen this already?



I'd really like to know what frequency ratios of oscillators B and C create static or cycling patterns (A & D produce a lissajous figure baseline)). My idea is to use something like an Arduino with some rotary encoders that jump between ideal frequencies.

There's not enough room on my workbench to hook up two of my (Nixie) frequency counters I have for the experiment. I would be extremely grateful if someone were to model it in an emulator that's free to use. One person did but then dropped out of sight without sharing it.


Utterly unrelated picture from Banggood—I found it while looking at digital microscopes:



Terry Bowman, KA4HJH
"The Mac Doctor"

https://www.astarcloseup.com

"Would you like to see the relevant data?"—343 Guilty Spark, Halo 2

liam bartosiewicz

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Apr 24, 2022, 5:31:24 PMApr 24
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Build an audio amplifier inside the case and use the screen as a spectrum analyzer, I don’t think I’ve seen that done before

On Apr 24, 2022, at 2:28 PM, Mac Doktor <themac...@gmail.com> wrote:


<PastedGraphic-1.png>


Terry Bowman, KA4HJH
"The Mac Doctor"

https://www.astarcloseup.com

"Would you like to see the relevant data?"—343 Guilty Spark, Halo 2

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John Rehwinkel

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Apr 24, 2022, 6:10:19 PMApr 24
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I'd really like to know what frequency ratios of oscillators B and C create static or cycling patterns (A & D produce a lissajous figure baseline)). My idea is to use something like an Arduino with some rotary encoders that jump between ideal frequencies.

Not high frequency at all, that project was from 1975.  Oscillator A is 60Hz, oscillator B is variable from 60-240Hz, oscillator C is variable from 300-3000Hz, and oscillator D is variable from 30-300Hz.

I've been using a Teensy board, that processor has a pair of built-in DACs, so it wasn't hard to have the old scopes display their own names.


- John

Mac Doktor

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Apr 24, 2022, 7:45:29 PMApr 24
to neonixie-l
On Apr 24, 2022, at 6:10 PM, 'John Rehwinkel' via neonixie-l <neoni...@googlegroups.com> wrote:

I'd really like to know what frequency ratios of oscillators B and C create static or cycling patterns (A & D produce a lissajous figure baseline)). My idea is to use something like an Arduino with some rotary encoders that jump between ideal frequencies.

Not high frequency at all, that project was from 1975.  Oscillator A is 60Hz, oscillator B is variable from 60-240Hz, oscillator C is variable from 300-3000Hz, and oscillator D is variable from 30-300Hz.

True but we're dealing with square waves here. Doing this digitally (which I am very interested in) requires a decent sampling rate to keep the corners sharp, which is a large part of the appeal of this analog version. Having tried it with a laser and some galvos I can tell you that good bandwidth makes a big difference. And that's as much as I know about it. I'm here to learn from you guys.


I've been using a Teensy board, that processor has a pair of built-in DACs, so it wasn't hard to have the old scopes display their own names.

8 bit DACs? Tell me more.


Terry Bowman, KA4HJH
"The Mac Doctor"


“...the book said something astonishing, a very big thought. The stars, it said, were suns but very far away. The Sun was a star but close up.”—Carl Sagan, "The Backbone Of Night", Cosmos, 1980


Toby Thain

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Apr 25, 2022, 9:44:57 AMApr 25
to neoni...@googlegroups.com, Mac Doktor
On 2022-04-24 7:45 p.m., Mac Doktor wrote:
>
>> On Apr 24, 2022, at 6:10 PM, 'John Rehwinkel' via neonixie-l
>> <neoni...@googlegroups.com <mailto:neoni...@googlegroups.com>> wrote:
>>
>>> I'd *really* like to know what frequency ratios of oscillators B and
>>> C create static or cycling patterns (A & D produce a lissajous figure
>>> baseline)). My idea is to use something like an Arduino with some
>>> rotary encoders that jump between ideal frequencies.
>>
>> Not high frequency at all, that project was from 1975.  Oscillator A
>> is 60Hz, oscillator B is variable from 60-240Hz, oscillator C is
>> variable from 300-3000Hz, and oscillator D is variable from 30-300Hz.
>
> True but we're dealing with square waves here. Doing this digitally
> (which I am very interested in) requires a decent sampling rate to keep
> the corners sharp, which is a large part of the appeal of this analog
> version. Having tried it with a laser and some galvos I can tell you
> that good bandwidth makes a big difference. And that's as much as I know
> about it. I'm here to learn from you guys.

I've been working on a vector generator. The first iteration is about
20k vectors/second but supports lines and points only (no circle
segments or anything fancy yet). Just finished routing the PCB.

It should be usable with most dev boards that use Arduino Uno pinout
(3.3v or 5v). I have been testing with NXP Freedom KE06Z but I expect to
port the code to Duemilanove and STM32 Nucleo G474RE at least.

Sample output: https://imgur.com/a/fZfqSmG

--Toby


>
>
>> I've been using a Teensy board, that processor has a pair of built-in
>> DACs, so it wasn't hard to have the old scopes display their own names.
>
> 8 bit DACs? Tell me more.
>
>
> Terry Bowman, KA4HJH
> "The Mac Doctor"
>
> https://www.astarcloseup.com <https://www.astarcloseup.com>
>
> “...the book said something astonishing, a very big thought. The stars,
> it said, were suns but very far away. The Sun was a star but close
> up.”—Carl Sagan, "The Backbone Of Night",/Cosmos/, 1980
>
>
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Paul Andrews

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Apr 25, 2022, 11:52:25 AMApr 25
to neonixie-l
It looks like it is almost working, so might be worth trying to repair, though space can be pretty tight in there. I was in a similar situation and chose to replace the electronics with a clock kit. I modified it heavily to also work as a bluetooth speaker with audio visualization https://youtu.be/3Jtd4h9_4nk.

An alternative to a clock is a vector graphics game mod (think battlezone and asteroids). This is one https://hackaday.com/2015/12/29/32c3-vector-video-games/, this is another https://hackaday.com/2020/05/07/scopetrex-is-a-game-console-for-your-oscilloscope/. I'm not sure if these are replacements, or if they just connect to the X/Y inputs of a working 'scope.

Nick Andrews

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Apr 25, 2022, 12:31:19 PMApr 25
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Pretty cool stuff.  The commenters on that first link are right though, you can reproduce all that vinyl distortion and noise digitally and make it sound identical, if that's what you're into.  Maybe one of these days I'll do a CRT clock.  Guess I should look for a nice CRT to hoard...

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John Rehwinkel

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Apr 25, 2022, 5:41:36 PMApr 25
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> I've been working on a vector generator. The first iteration is about 20k vectors/second but supports lines and points only (no circle segments or anything fancy yet). Just finished routing the PCB.

I'm very interested in that. I'm also working on an analog vector generator (op-amp configured as an integrator plus an analog switch to discharge the integrating capacitor), but it sounds like you're much farther along.

- John

John Rehwinkel

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Apr 25, 2022, 5:43:01 PMApr 25
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> Do you want to part with one of the larger scopes? High bandwidth isn't an issue here but I do need an X/Y display. Scope clock kits are out of my price range. I simply don't want one bad enough.

I'd be happy to part with some to a good home. Shipping can be expensive, but maybe you're not too far off (I'm in northern Virginia, near Harpers Ferry).

- John

gregebert

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Apr 25, 2022, 6:06:43 PMApr 25
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Before you part with any of them, I hope you can post a photo collage of your restored collection. So many of those old green-phosphor / round-faced scopes are nostalgic treasures.

Now I'm having guilt feelings for throwing my working Dumont 304H in the trash 20 years ago.....

Toby Thain

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Apr 25, 2022, 6:25:04 PMApr 25
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On 2022-04-25 5:41 p.m., 'John Rehwinkel' via neonixie-l wrote:
>> I've been working on a vector generator. The first iteration is about 20k vectors/second but supports lines and points only (no circle segments or anything fancy yet). Just finished routing the PCB.
>
> I'm very interested in that. I'm also working on an analog vector generator (op-amp configured as an integrator plus an analog switch to discharge the integrating capacitor), but it sounds like you're much farther along.

Hi John,

I'll be ordering pcbs soon, so get in quick if you'd like a blank for
cost and postage.

I can populate and test, but clearly that will cost a lot more,
especially with current component availability and prices etc.



--Toby


>
> - John
>

Mac Doktor

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Apr 25, 2022, 6:46:05 PMApr 25
to neonixie-l
On Apr 25, 2022, at 6:24 PM, Toby Thain <to...@telegraphics.com.au> wrote:

On 2022-04-25 5:41 p.m., 'John Rehwinkel' via neonixie-l wrote:
I'm very interested in that.  I'm also working on an analog vector generator (op-amp configured as an integrator plus an analog switch to discharge the integrating capacitor), but it sounds like you're much farther along.

I'll be ordering pcbs soon, so get in quick if you'd like a blank for cost and postage.

All through-hole parts, right? If so put me down for one. Two if they're not too expensive.

Sadly, I had to sell my Atari Tempest. That had a daughterboard full of SSI and MSI. It may have done the square roots.


Terry Bowman, KA4HJH
"The Mac Doctor"

"If only you could see what I've seen with your eyes."—Roy Batty, Blade Runner

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