Flat screen analog oscilloscope .. ?

Jump to Latest
#2
> works like old fashioned

You mean, with knobs instead of buttons?

Knobs are dying technology. Buttons suck but are real cheap.

If you are a true knob-lover, build a knob-controlled front-end and leave the button-scope at fixed settings.

There are scads of 'scopes for PCs, both sound-card input and dedicated box interface.
 
#5
> You mean, with knobs instead of buttons?

No .... I mean locks onto and displays the signal real time ...
No storage ..... Probably no characters ....
Actually it would be essentially a ( say ) 8 bit x 8 bit matrix
analog ramp generator driving columns and signal driving
rows ..... concept so simple but I can't figure out how to
interface the analog to say ( best case ) a hdmi
( or even composite would be O.K. ) monitor .
 
#6
Analog scope deflects the electron beam in one direction by the time base, in the other direction by the measured signal. While a standard display device supports only several timing modes. For aligning the two time domains you would need... the storage, to allow displaying in a different rate than capturing.
 
#7
hitsware said:
...
Such a thing ?
I would like an oscilloscope that works like old fashioned CRT type ,
but with solid state display .
There used to be plans for making an oscilloscope from a T.V.
Is there now an analog circuit that will drive ????? HDMI monitor ?
Click to expand...


Such a thing ? Basically no. The idea behind the old CRT scopes was different - make a continuous scan from left to right with the bandwidth of the scope. An advantage was that you could see any deformation of the curve the noise-level and bandwidth would allow. It reflected the technology available during that period. The disadvantages were many - among other storage was difficult. An LCD or similar screen made up of numerically controlled pixels cannot behave like a CRT - it can emulate a CRT-scope with some limitations.
The sampled scope has few limitations that mainly relate to the speed and resolution of the sampling. It will improve with time and apart from multiple colors on the screen, data can be manipulated and presented in endless ways. The sampled scope will increasingly be able to behave like a CRT-scope on top of the sampled scope advantages.
 
Last edited:
#8
phofman said:
Analog scope deflects the electron beam in one direction by the time base, in the other direction by the measured signal. While a standard display device supports only several timing modes. For aligning the two time domains you would need... the storage, to allow displaying in a different rate than capturing.
Click to expand...

Say you have a led matrix
Columns are driven one at a time by a ramp into a flash ADC then through
a parallel to 255 step generator
Rows driven one at a time by measured signal into flash ADC then through
a parallel to 255 step generator
The signal would not lock without adjustment , but it should act like a CRT ...
one pixel at a time fired ..
 
#10
Yes, you can build a dedicated flat panel instead of the CRT. But you asked about HDMI or composite signal, using regular TV. These support only one or very few frequency modes.

Another issue is speed - electrostatic deflection in the scope CRTs is pretty fast, luminiscent layer on the screen lights up pretty fast too, unlike digital display drivers.

When you already have the data sampled by ADC, why would you need to display them in real-time?
 
#11
hitsware said:
...
Such a thing ?
I would like an oscilloscope that works like old fashioned CRT type ,
but with solid state display .
There used to be plans for making an oscilloscope from a T.V.
Is there now an analog circuit that will drive ????? HDMI monitor ?
Click to expand...

I love my old analogue scope with CRT.
I have been using one for 40 years so sort of got stuck in my ways.
These new scopes with loads of buttons and menu's is (for me) user unfriendly.

I design USB PC scopes and love the big screen display I get on my PC.
The scope display fills the screen and a right click of the mouse brings up all the options.
 
#16
hitsware said:
> why would you need to display them in real-time?

Has a way better ' feel ' ..... Or perhaps I've simply never gotten
a digital scope adjusted right ?
Click to expand...

I've been using digital scopes since '93 starting with a Tek TDS3034 at one job and TDS3054 at the other. I
currently have at work a Tek MDO3024 which includes a 3GHz spectrum analyzer. For home I have a
Rigol DS1054Z but it's hacked to a DS1104Z and a Tek 475. I've had the Tek for 30 years and it still works
well but try looking at a serial datastream. The MDO and Rigol will decode the data and show you the value in
hex or binary or ASCII. An analog scope has low persistence so erratic events are tough to sort out. A digital
scope freezes the display indefinitely so you can examine it. You can also screen grab onto a flash drive.
I think it's better to think of a digital scope as a data acquisition unit with a user interface that mimics an oscilloscope.
Folks say you can look at noise better with an analog scope because the digital is only 8 or 9 bits but using
averaging you really can get the job done. My analog scope has sadly become a really fancy paperweight.

The last time I used the analog scope I wanted to do something you can only do on a digital scope. Right after
that I bought the Rigol as a Christmas gift to me - with the wife's approval. You won't find a much better value
than the Rigol.

G²
 
#17
All my analog scopes (9 I think) have flat CRT's. You really need to go old and down market to get a CRT scope with a curved faceplate. . .

What is on my to-do list is a plugin interface for Tek 7000 plugins to a digital scope. Get the extreme flexibility of those plugins with a nice digital display. It should not be too difficult to do.
 
#18
hitsware said:
> emulating a CRT-scope but it will not be a CRT-scope.

RIGHT !
Click to expand...

There were conversion kits for a couple Agilent VNAs, I think, to go from CRT to LCD. The problem is there is little demand. For a scope there are questions of speed / refresh rate / response time.

If you want a scope that "feels" more analog, try an Agilent/Keysight one with 1M waveforms/sec update rate. They are good for debug and finding intermittent events and runts compared to most other digital scopes.
 
#19
The HP/Agilent VNA's used the CRT has a display for digitally generated images using VGA signaling. Most have a connector on the back you can rout to an RGB monitor. Thats why the LCD conversions are possible and pretty attractive if the CRT is going. Its not really a valid comparison.
 
#20
To me it is still not really clear what you are after...

- A measurement tool that remains analog i.e. no quantisation involved?
- The physical shape and size of an old florescent screen, but completely flat?
- The visual presentation of an old florescent screen on a bigger screen?
- The visual presentation of an old florescent screen on same size screen but flat?
- There shall be knobs?
- A bigger screen for visibility?

You are presenting a "solution" to a problem it seems - what is the original problem? Eyesight? Doubt about digital accuracy?


//
 
You must log in or register to reply here.
Top Bottom