Low end 'scopes

Hey Win, I'm thinking of writing a review to post on a physics 'lab guy' list server. I figure I'll send a copy to the Keysight rep. He wants to give us a deal on replacing ~10 Tek scopes, I'm not making money on it directly, but my company may be getting a 'scope upgrade on it's trailer for ~'free'.

Is it OK if I quote you? It's no big deal if you say no, and no quotes without a yes.

George H. (It might get quoted in a company newsletter too.)

e:

ppy)

nal

h from Sunnking, right in your neighbourhood, and in an hour you can conver t it to a TDS 784A (1 GHz, 4 Gs/s). It does FFTs and such as well. If you feel flush, you can put in a Newscope LCD kit from Simmconn Labs, which is _beautiful_. (I have two like that.)

Yeah, I don't know the 7k series very well. I remember issues with plug-in connections, (late 80's?) but that very well could have been clueless (physics) grad students.

I'm (mostly) in the business of selling kit to schools, This 'scope is clearly superior to it's TEK competitor, and my older Rigol.

(I think Joerg's, 'triggering on a low level signal buried in crap', test is telling... I'm demanding one of these 'scopes for my own as part of the review, I'll let ya know if that works out. :^)

George H.

The $300 scope has a the left side of the front panel bashed in and held in place by duct tape. The floppy drive also looks crushed. Sunnking calls this "refurbished". Still, it's repairable and very tempting.

The replacement LCD will probably have to wait.

Thanks for the suggestions.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Skype: JeffLiebermann     AE6KS    831-336-2558

I've had excellent luck with Sunnking--they consistently ship good stuff, packed really well, and it's always worked. So if they say "refurbished", the odds of it working are pretty good IME.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC / Hobbs ElectroOptics 
Optics, Electro-optics, Photonics, Analog Electronics 
Briarcliff Manor NY 10510 

http://electrooptical.net 
https://hobbs-eo.com

Hi, George,

Can you post a link to the listserv? It sounds interesting.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC / Hobbs ElectroOptics 
Optics, Electro-optics, Photonics, Analog Electronics 
Briarcliff Manor NY 10510 

http://electrooptical.net 
https://hobbs-eo.com

Well the traffic is not all that high, but sometimes there are some interesting discussions. advlabs-l

maybe here,

George H.

TDS 744A (etc.) != '7k series'

-- Sceptre

--
sceptre@sdf.org 
SDF Public Access UNIX System - http://sdf.org

Also, looking at the photo, it seems like it's the bezel that's pushed outwards, not the drive that's pushed in. At that price I might buy it myself.

Cheers

Phil Hobbs

(Coming to you from scenic Adare, Co. Limerick, Eire)

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC / Hobbs ElectroOptics 
Optics, Electro-optics, Photonics, Analog Electronics 
Briarcliff Manor NY 10510 

http://electrooptical.net 
https://hobbs-eo.com

Right, thanks.

George H.

The plastic bezel was certain bashed in, but I have some concerns about the condition of the cast aluminum (or plastic) mounting for the floppy drive.

From the dirt embedded into the plastic, my guess(tm) is that it was dropped hard on this corner causing the front panel to move backwards. The scope was then opened, but the front plastic bezel not removed. Some of the mangled sheet metal was bent back into shape, but the floppy drive could not be repositioned in its original location.

I found this photo showing the floppy drive and it's mounting hardware: It looks like it would have been easy to bend the floppy mounting hardware back into position, unless the mounting hardware for the floppy drive was part of the cast aluminum or plastic shield. A cracked casting would explain the rather odd floppy drive angle and why it wasn't subsequently repaired and repositioned. The drop might also have caused the floppy drive to hit and bend the main board. I'm doing quite a bit of guesswork here, but there has to be a reason for why an alleged reputable refurbisher would leave such obvious damage in place.

I was very much interested in this scope, but decided not to buy it mostly because I don't have any projects pending that might require it. It's all yours. Before you buy, I would strongly suggest you ask for a photo of the inside showing the floppy drive mountings.

The price is not exactly a bargain as other TDS744A scopes have sold for only slightly more:

Have a good time in Ireland.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

I like the scope a lot, and have looked at its competition, so yes you can quote me on that. But then you have to add that the probes they provide with the scope are terrible. They have a x1 x10 gain switch, but the probe/scope doesn't recognize the setting; you have to go to a menu to manually change the readout. Also, the switch is flaky, so sometimes your screen is off by 10x from where you think it is.

--
 Thanks, 
    - Win

Thanks Win, probe objection noted. I hadn't looked at the probes, I don't like the switched gain ones either. Sadly, it's only a small fraction of my physics brethren that know when to use the x10 probe... or even the x1. Alligator clips or little grabber probes are the norm.

George H.

The 7514 is gorgeous isn't it? I still have 3 or 4 analogue storage scopes; the Tek one I have is the 466. It's also gorgeous, but doesn't have the arresting 'presence' of the 7514.

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Quote "The unit turns on, passes the self test and we were able get all

4 channels to display on the screen". That doesn't sound like a "refurbished" claim.

It looks like that scope took a fall onto the floor or experienced a "union toss" at a shipper.

If the old CRT screen still works why replace it?

--
Regards, Joerg 

http://www.analogconsultants.com/

"I tried to change the scope to 1kV/div but it refused to go there and now nothing is displayed anymore" :-)

--
SCNR, Joerg 

http://www.analogconsultants.com/

I asked them, and they said that it passes SPC and triggers on all four channels, but that they haven't got a floppy disk handy to test it with.

Yup, probably fell off a bench, but the CRT survived.

If it's still bright enough that I don't have to squint to read the display text, it doesn't need replacing. However, a $300 scope probably isn't in that class. ;)

I probably don't need a third TDS 784A, and there's enough stuff in my lab that we're getting close to failing the cat test.

Cheers

Phil Hobbs