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Products => Test Equipment => Topic started by: dizz on December 16, 2016, 10:19:57 pm

Title: What in the world is a 'hard copy' oscilloscope?
Post by: dizz on December 16, 2016, 10:19:57 pm
This ebay listing here is calling this a 'hard copy'

What is the idea here?

(http://i.ebayimg.com/images/g/XggAAOSwEzxYSz5C/s-l1600.jpg)

http://www.ebay.com/itm/Tektronix-2252-100MHz-Prog-Hard-Copy-Oscilloscope-/232169748323 (http://www.ebay.com/itm/Tektronix-2252-100MHz-Prog-Hard-Copy-Oscilloscope-/232169748323)

Thanks in advance
Title: Re: What in the world is a 'hard copy' oscilloscope?
Post by: Gyro on December 16, 2016, 10:26:54 pm
I know rebadging is rife but that's ridiculous!  :-DD

(Sorry, couldn't resist)
Title: Re: What in the world is a 'hard copy' oscilloscope?
Post by: madires on December 16, 2016, 10:32:32 pm
Electrical isolation to prevent you from touching the case/ground. "Grid", "Heater" and "Cathode" should tell you why ;)
Title: Re: What in the world is a 'hard copy' oscilloscope?
Post by: Gyro on December 16, 2016, 10:35:00 pm
Agreed, some serious high voltage isolation.
Title: Re: What in the world is a 'hard copy' oscilloscope?
Post by: StillTrying on December 16, 2016, 11:03:42 pm
Yep, that would be hard to copy.
http://www.tek.com/manual-topic/printing-hard-copy-0 (http://www.tek.com/manual-topic/printing-hard-copy-0)
Title: Re: What in the world is a 'hard copy' oscilloscope?
Post by: nctnico on December 16, 2016, 11:18:21 pm
This must be the ultimate floating scope!

BTW it says 'harcopy scope' on the badge and it seems to have a PC style printer port on the back. I have not seen this before so it may actually be a very rare model.
Title: Re: What in the world is a 'hard copy' oscilloscope?
Post by: mikeselectricstuff on December 16, 2016, 11:47:08 pm
It has a digitizer to allow printouts of waveforms - see this manual :
http://exodus.poly.edu/~kurt/manuals/manuals/Tektronix/TEK%202252%20Operations.pdf (http://exodus.poly.edu/~kurt/manuals/manuals/Tektronix/TEK%202252%20Operations.pdf)

Looks like it used a low-speed ADC to digitise repetitive waveforms in sequential sampling mode, from :
http://w140.com/tekwiki/images/3/38/Tek_2252_2247A_2245A_Specs.pdf (http://w140.com/tekwiki/images/3/38/Tek_2252_2247A_2245A_Specs.pdf)
Title: Re: What in the world is a 'hard copy' oscilloscope?
Post by: tggzzz on December 16, 2016, 11:49:21 pm
When somebody falsely claims it is OK to "float a scope", you can say "it is safe in some circumstances; see this picture for what is necessary".
Title: Re: What in the world is a 'hard copy' oscilloscope?
Post by: joeqsmith on December 17, 2016, 01:24:06 am
I want to see whatever it was attached to.   
Title: Re: What in the world is a 'hard copy' oscilloscope?
Post by: SeanB on December 17, 2016, 06:30:38 am
Probably the cathode of a large SEM, to monitor the  current waveform as it scanned.
Title: Re: What in the world is a 'hard copy' oscilloscope?
Post by: jonovid on December 17, 2016, 06:38:23 am
 :wtf: hot glue gun sticks? 
Title: Re: What in the world is a 'hard copy' oscilloscope?
Post by: Monkeh on December 17, 2016, 06:59:34 am
:wtf: hot glue gun sticks?

Nylon or acetal rods.
Title: Re: What in the world is a 'hard copy' oscilloscope?
Post by: ebclr on December 17, 2016, 08:32:21 am
Sold for USD 64.14 it a very fair price
Title: Re: What in the world is a 'hard copy' oscilloscope?
Post by: electrolust on December 17, 2016, 10:36:14 am
I'm guessing the offset front is to place a camera?  Might be hard to work around the intended camera hence the extended controls.

But why a camera if it can print out a copy?  Maybe the printout doesn't have the reticle etc.
Title: Re: What in the world is a 'hard copy' oscilloscope?
Post by: mikeselectricstuff on December 17, 2016, 10:54:33 am
I'm guessing the offset front is to place a camera?  Might be hard to work around the intended camera hence the extended controls.

But why a camera if it can print out a copy?  Maybe the printout doesn't have the reticle etc.
And it can only print repetitive waveforms
Title: Re: What in the world is a 'hard copy' oscilloscope?
Post by: nctnico on December 17, 2016, 11:01:24 am
I'm guessing the offset front is to place a camera?  Might be hard to work around the intended camera hence the extended controls.

But why a camera if it can print out a copy?  Maybe the printout doesn't have the reticle etc.
These Tektronix scopes have grooves to hold a camera so I doubt they went through all the trouble just to take a picture of the screen.
Title: Re: What in the world is a 'hard copy' oscilloscope?
Post by: Luminax on December 17, 2016, 01:22:54 pm
What's those strange waveform on the display?
Title: Re: What in the world is a 'hard copy' oscilloscope?
Post by: Fungus on December 17, 2016, 03:16:14 pm
These Tektronix scopes have grooves to hold a camera so I doubt they went through all the trouble just to take a picture of the screen.

Maybe it had some sort of optical->paper printer in the empty space.  :popcorn:
Title: Re: What in the world is a 'hard copy' oscilloscope?
Post by: PointyOintment on December 17, 2016, 03:19:54 pm
What's those strange waveform on the display?

I think that's actually text. Not sure what it says, though.
Title: Re: What in the world is a 'hard copy' oscilloscope?
Post by: David Hess on December 17, 2016, 05:02:39 pm
It has a digitizer to allow printouts of waveforms - see this manual :
http://exodus.poly.edu/~kurt/manuals/manuals/Tektronix/TEK%202252%20Operations.pdf (http://exodus.poly.edu/~kurt/manuals/manuals/Tektronix/TEK%202252%20Operations.pdf)

Looks like it used a low-speed ADC to digitize repetitive waveforms in sequential sampling mode, from :
http://w140.com/tekwiki/images/3/38/Tek_2252_2247A_2245A_Specs.pdf (http://w140.com/tekwiki/images/3/38/Tek_2252_2247A_2245A_Specs.pdf)

This is exactly it.  The 2252 uses sequential sampling to capture a repetitive waveform of 500 horizontal points or 50 points/div and 12-bit vertical resolution at full bandwidth which can then be transferred to a computer over GPIB or printed via a Centronics interface.  All 5 traces can be captured at once.

No other ability to manipulate or display captured waveforms is possible so it is literally an analog oscilloscope with digital hardcopy capability.  If the hardcopy capability is ignored, then it is a 2247A which is a great oscilloscope.

We got the story on these years ago over at TekScopes@yahoogroups.com.  Apparently Tektronix got curious and asked why they needed so many replacement front panels.  They were measuring high voltage tubes of some sort, maybe TWTs.