Tek TDS scopes--which to buy?

That's par for the course for a good 1GHz 4GS/s+ scope

A TDS784A for $1500 is VERY cheap. At that price it's either an absolute bargain, or there is something wrong with it.

The 784A is only 4GS/s on one channel, dropping to 2GS/s on multiple channels. The 684B is 5GS/s on all channels, that costs extra. The 784A has more memory though, 50K vs 15K.

What specs do you really need?

Dave.

That's par for the course for a good 1GHz 4GS/s+ scope

A TDS784A for $1500 is VERY cheap. At that price it's either an absolute bargain, or there is something wrong with it.

The 784A is only 4GS/s on one channel, dropping to 2GS/s on multiple channels. The 684B is 5GS/s on all channels, that costs extra. The 784A has more memory though, 50K vs 15K.

What specs do you really need?

Dave.

Phil Hobbs wrote in news:Vr2dnWhtr-WaQ3_UnZ2dnUVZ snipped-for-privacy@supernews.com:

if you're buying used; don't forget to check the TEK website for the long-term support period(LTPS). Once it's past that,parts and repair services from TEK will be non-existant(calibration will still be available). And TDS-series service manuals do not have component level schematics. they are "module exchange" serviced.Use their "repair and return" service at your own risk;they might lose your assembly.

--
Jim Yanik
jyanik
at
kua.net

Really? We have one, we never use it. Press AUTOSET, it invariably chooses wrong settings on a simple clock waveform.

Isn't that the definition of AUTOSET functionality on any brand scope? :-)

Maybe I'm just too cynical, but no matter what the brand I find that autoset never comes up with the display I actually wanted. The Tek implementation seems better than most in that it sometimes comes close.

Tim.

I'd go for a color LCD scope; they're wonderful.

Do you need single-shot GHz bandwidth? If not, the combination of a relatively cheap 100-200 MHz color LCD scope and a 20 GHz sampler could be done fairly inexpensively.

John

Maybe, I don't know. My cheap Rigol at home actually does pretty good on autoset. I was always too macho to use autoset (having been raised on old 500 series Tek gear like the 547) but the Rigol does great, now I get upset when other scopes don't do as well.

The thing with the 684 is that it picked a very slow time base (in the ms range) for a 62MHz clock and the display showed an unlocked square wave but the trigger said it was working. Of course I was looking at an aliased version but how hard is it to get it right? There are scopes from the 60s with autoset that work better, and they did it with three transistors and a tunnel diode...

Yes. The purpose of the AUTOSET button on scopes is so that the salesguy demonstrating the thing to you can hook a probe up to the 1kHz calibrator output and then only need to remember one button to press to complete his demo. :-)

"Maybe I'm just too cynical, but no matter what the brand I find that autoset never comes up with the display I actually wanted."

"PRESET" buttons are a lot more useful.

---Joel

Yep, I've got an Instek GDS-2204, happy with it and doesn't break the bank. Plus you'll get the new car smell.

My dream would have been the Hameg 2008 CombiScope, analog plus digital and a sample memory length from here to the Klondike. But it wasn't easy to find at a reasonable price in the US back then, this was when the Euro soared to over $1.50.

Any hints as to which sampler?

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
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I have just realised I have *never* used the autoset button on my TDS3054 - in fact I just had to go check to see if it actually had one.

I've had it 10 years and use it practically daily...

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John Devereux

I like the Tek 11801/CSA800 series, and the SD-series heads. You can get a working mainframe on ebay for under $1K, and a 12 GHz dual-channel head (SD-22) for maybe $500, or a 20 GHz TDR head (SD-24) for maybe $1K.

The TDR/TDT thing is stunning.

John

Ok, that I knew. I thought you meant some small wonder box that would do the sampling and output to a regular DSO. My wife would have a little fit if I crammed another mainframe in here. The lab bench row is already

5-6 feet high as it is. Plus what am I going to do with all this stuff when my last days draw nearer?

--
Regards, Joerg

http://www.analogconsultants.com/

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You're supposed to keep a closest full of those big mainframes and swap them in and out as needed. :-)

I'd say give'em to John, but I believe he's older than you!

Seriously, though, the Agilent and Tek Yahoo! groups are filled with people who'd love to take this sort of gear off your hands... and there's always eBay, of course.

---Joel

If you buy a new scope, Tek will give you 15% trade-in (and most likely crush the old scope to prevent it from depressing prices).

Good idea. At least then it gets into caring hands. When the time comes I might do it the non-profit way, net proceeds go straight to church.

--
Regards, Joerg

http://www.analogconsultants.com/

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My TDS2014 has an AUTOSET button that works pretty well. And even better, when it's done one of the soft buttons is "UNDO". I really miss the undo when dealing with other Tek scopes -- especially the ones where AUTOSET is right next to RUN/STOP or something.

--
Ben Jackson AD7GD

http://www.ben.com/

Watch out. When I did that a few years ago the scope section was full of bogus listings. You'd complain about a bogus listing and it would go away, only to appear again (same picture, same text) being sold by yet another grandmother whose previous ebay experience was selling yarn and porcelain figures.

--
Ben Jackson AD7GD

http://www.ben.com/

I don't recall every having used AUTOSET.

Cheers

Phil Hobbs

I'll give you $1500 for it.

Cheers

Phil Hobbs