Author Topic: #187 - Tektronix TDS 2024 C Teardown  (Read 4711 times)

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Offline Richard W.

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#187 - Tektronix TDS 2024 C Teardown
« on: July 22, 2011, 05:20:32 AM »
Hello,

nice teardown, I like it very much.
I always wondered how it looks inside and now i don't need to open up my scope any more  ;D  thanks Dave

Have you actually measured the powerconsumtion of the scope?
Do you know the rating of the fuse?

I don't know why you don't like the design... I think its very clear and nice. Nothing fancy but decent.
It is a scope, not a sportscar.

with best regards
Richard
 

Offline tesla500

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Re: #187 - Tektronix TDS 2024 C Teardown
« Reply #1 on: July 22, 2011, 07:09:13 AM »
What puzzled me is at about 16:00 in the video: if you look carefully at the front end, there is NO variable capacitor for probe compensation...

Because the probe already contains that?
Because they're OK with the tolerance of fixed and parasitic capacitances on the input in this cheap scope?
 

Offline tesla500

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Re: #187 - Tektronix TDS 2024 C Teardown
« Reply #2 on: July 22, 2011, 09:46:04 AM »
Because the probe already contains that?
Because they're OK with the tolerance of fixed and parasitic capacitances on the input in this cheap scope?
No :P

What's the purpose of the cap when they do have it? Do they need to trim the capacitance across the input to a very tight tolerance? Or does this cap do something else?
 

Offline tesla500

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Re: #187 - Tektronix TDS 2024 C Teardown
« Reply #3 on: July 23, 2011, 05:57:37 AM »
Ahh, if you had said "attenuator compensation" I would have known exactly what you meant. Probe compensation is something totally different.

I'm still not seeing what they're doing. Other guesses are:

  • Very tight tolerance/custom value fixed capacitors
  • Laser trimmed capacitors (is that even possible?)
  • Capacitors built into PCB layers, with vias drilled out to disable them
  • "Capacitor DAC" with FETs switching in or out caps sized in powers of two (is that what those groups of 4 caps below the EE04AB chips are?
  • Varicap didoe (seems like a bad idea)
  • Digital compensation inside the ADC or ASIC for not quite perfectly compensated attenuator
  • Analog compensation inside the amplifier ASIC

I'm presuming the EE04AB chips are amplifiers, and the EE05AF chips are ADCs. The big ASICs also have the national semiconductor logo, they probably did the entire ASIC set for this scope.

Tek REALLY needs to retire this archetecture. Other than the sample depth, it's just so unresponsive to the controls. I really hate it whenever I have to use one of these scopes. I press a button or turn a knob, and a second later it responds. The Agilent scopes, even old ones from the 90s, respond virtually instantly, Using a 14MHz CPU no less (in the 54622 that I opened up)!
 

Offline EEVblog

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Re: #187 - Tektronix TDS 2024 C Teardown
« Reply #4 on: July 23, 2011, 05:16:08 PM »
I saw this on the Tek home page, frigg'n hilarious!
The TDS2000C series won an "Annual Creativity" award from EEtimes! ROFL!

Dave.
 

Offline [email protected]

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Re: #187 - Tektronix TDS 2024 C Teardown
« Reply #5 on: July 23, 2011, 06:11:50 PM »
Does someone know the going rate of what it takes to *cough* convince *cough* the likes of EEtimes to give you an award? Or to buy advertising disguised as an article?

If it isn't too expensive we maybe could buy some award for the eevblog.
I delete PMs unread. If you have something to say, say it in public.
For all else: Profile->[Modify Profile]Buddies/Ignore List->Edit Ignore List
 


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