Tek 2230 Single-shot capacity

[McPete]

G'day all,

I've got a Tek 2230 DSO on my bench at work, and I've been trying to get a capture of a switch bounce. I can get it to display a constant waveform pretty easily, but for the life of me, I can't get it to just grab a single event. Does anyone here have experience with this particular model or series so they can straighten me out as to what I might be doing wrong?

Thanks,
P.

[Simon]

you need to go into the trigger settings and set it to trigger on a rising or falling voltage of a set voltage you need to work out, I don't have that model but based on my Rigol it is a trigger related setting

[EEVblog]

Haven't used one before, but you likely need to set to SGL SWP and NORM trigger modes to get a single shot capture.

Dave.

[rf-loop]

All these settings are well and accurate explained in this operators manual. This manual is just as all manuals from TEK (old times) just different if compare today cheap scopes "manual". Tek manual is nearly perfect. Nobody write this kind of manuals for today (cheap) scopes example as rigol or other this kind of toys. (but still useable for many hobby use)

http://bama.edebris.com/download/tek/2230/2230opsPART1.pdf

http://bama.edebris.com/download/tek/2230/2230opsPART2.pdf

If this manua do not help Tek (and HP) have also "abc" for oscilloscopes.

If you want single shot digi capture you need also remember single shot limits for 20Ms/s maximum.

As eevblog tell. Trig single, mode norm, trig source (what you use) trig (horizontal) position, and trig level (you need know what voltage level you want trig and set this level, and slope direction of course. Then start and you see Trig'd led light (ready for find trig) and after it find state where trig this led go off (in single shot mode). (trig control settings quick info you find manual part 1 starting side 3-9. More deep info you need read more this huge manual.
(but remember digital storage mode and normal mode differencies (and digitizing) single shot record limits. These you can all find in manual.

Nice scope for low freq signals... and it have 10 bit resolution!

Specially Tek scopes (specially these older models and more specially pure analog (high-end) scopes) have maybe best trig system what can find in older scopes. Just trig is this secret why there is old phrase: If you need good oscilloscope you have 3 posibilities... 1. Tek, 2. Tek, 3. Tek,  and today it is still meaningfull for good old analog scopes and also some digital scopes (real vector CRT models)
(and ... it is not only speedmeter maximum in car and sampling speed speed and color screen in scope what is meaningful for thinking value as tool.)

[McPete]

Ah, fantastic! I only have a "reference" booklet, which isn't at all clear- I try to get some time to fiddle with that later today. Thanks!

[chscholz]

Are you sure about that?

If I interpret the spec sheet correctly is is an 8 bit scope (Table 1-1, page 1.2: "Storage Acquisition Vertical Resolution: 8 bits [...]")

Chris

Nice scope for low freq signals... and it have 10 bit resolution!

[rf-loop]

Yes I was surprised this when I hurry search this manual only Trig in mind and this case my eyes only snapshot some other info also.... (I also make note my mind that I need later check this whole resolution case better but then... I forget it.) So I am now littlebit wrong...sorry!

But this is what I see and make too fast opinion (without checking agen better) and then littlebit later I write my comment doing other things same time... so this mistake. But, still this part of specifications are still in my mind and later I want look more carefully what it really mean. (I have not this scope model but many other old) nice Tek's and HP's)

Here is this info what I read and make too fast opinion... and also there read "vertical resolution 10bits" bit ....but it is Digital storage display specs!




But not all digital storage scope do this  (many older scope keep display resolution also in averaging):




But real A/D acquisition resolution  is 8 bits. ( I can not compare ADC total quality becouse I have not this scope but... maybe not bad... noise is maybe low... (vertical and ADC timing noise)

[chscholz]

Yes, boxcar averaging is a standard method that all modern scopes offer, this is often called "enhanced resolution". Problem is you loose bandwidth rapidly. A viable option if you can afford a high-enough bandwidth scope.

As far as I know (please correct me if I am wrong, have not worked with scopes for that long), LeCroy was the only company that ever built a real-time scope with larger than 8 bit (hardware) resolution.

BTW [equivalent time] sampling scopes usually have 14 bit resolution.

Chris

[scrat]

Yes, boxcar averaging is a standard method that all modern scopes offer, this is often called "enhanced resolution". Problem is you loose bandwidth rapidly. A viable option if you can afford a high-enough bandwidth scope.
...
Chris

Yes, it was the way they achieved 16-bit resolution in early CD-ROM audio recording (and the principle behind sigma-delta ADCs).
If you do some calculations, for a signal which is (statistically) uniformly distributed over the discretizing range, each bit (at high bitrate) yields +6dB in SNR. So, oversampling 4x and filtering out-of-band discretization noise (3/4 the total noise) is equivalent to adding 1 bit in resolution.

Oscilloscope and spectrum analyzer's datasheet are often tricky (for example, that "10-bits vertical resolution" seems ambiguous at a first read), and for high-end instruments it is difficult to compare different brands (they don't state clearly some fundamental performances).

[alm]

As far as I know (please correct me if I am wrong, have not worked with scopes for that long), LeCroy was the only company that ever built a real-time scope with larger than 8 bit (hardware) resolution.

I believe there were some >8-bit scopes in the Tek 11000 series, these were real-time (but are pretty old, so fairly slow sampling rate).

From http://www.barrytech.com/tektronix/tek11000/tek11000scopes.html:

11403  1 GHz Color Digitizing mainframe, 20 MS/s.  High precision scope, 10-bit A/D (14 bits w/averaging).  The 11403 adds color display plus a new, more reliable digitizer over the 11402A.

[chscholz]

Thank you Alm, I stand corrected.

I believe there were some >8-bit scopes in the Tek 11000 series, these were real-time (but are pretty old, so fairly slow sampling rate).