Oscilloscopes

[mypasswordis]

I didn't find anything in search, which was surprising. Maybe I suck at searching. Anyway, a couple q's for those that own one or more:

1) How do vintage ones hold up? How often do they need recalibration? I'm not talking about serious vintage, with 50 tubes inside, but 1970s to 1980s solid state stuff.

2) Specific brands to look for/avoid?

3) What's the cheapest decent digital oscilloscope that can be hooked up to a PC? This or something close to it is what I'm used to using in the labs (yes I know it's a couple thousand... used): Digital Phosphor Oscilloscopes: TDS3000C Series > Data Sheets : Tektronix Specifically TDS3012B.

4) How useful/not useful has it been to be able to/not be able to save single shots as images?

5) How does this look? Lab Grade Tektronix Model 7844 Oscilloscope for SALE

I'll have to figure out bandwidth myself, I don't want to just use it for audio.

[luvdunhill]

Budget, bandwidth, channels, connectivity, screen type, FFT? Rigol or TDS220?

[mypasswordis]

Cost definitely under $1k preferably under $500, bandwidth around 100 MHz, channels >=2, connectivity... uhh Ethernet or USB is fine?, LCD or whatever I guess (don't mind if no color), FFT = yes please? I'll look up Rigol or TDS220, thanks. The TDS220 does seem pretty similar to the 3012B. I've definitely been spoiled by all the nice features of the 3012B...

Test rig cost ftl.

[Pars]

Tektronix 465b

oops, no color, no markers, etc. No digital. Great basic '80s SS scope.

[mypasswordis]

Hm, the convenience of these new digital ones may win me over. Currently thinking it would be cool to get a DS1052E and then install a logic analyzer board and hack it to 100MHz. DIY for DIY.

[n_maher]

Be prepared for serious expense beyond just the scope.

[luvdunhill]

I wish I had a logic analyzer plug in myself. That perhaps would be the greatest reason to go for the Rigol really, as once you add this to the Tek units the prices really skyrocket. If you do your homework, you'll find an interesting relationship between the Rigol scopes and Agilent. Another brand to consider if you're going more toward the digital side would be some of the entry level LeCroy units. Alternatively, you could consider something like this, which does a pretty good job, given the price and size:

Welcome to Saleae

[justin]

Tektronix 465b

oops, no color, no markers, etc. No digital. Great basic '80s SS scope.

i have a 475 i'd recommend you check out too. a good thing about these is there's not really any obsolete ICs that you won't be able to replace. biggest issue you'll run into is having to clean the switches. try to find one on ebay that has already been restored and it will still only cost you a few hundred, a bargain

[Nebby]

That 7844 is sold, I asked a while back

[kevin gilmore]

If you want interesting and cheap and new... I saw and played with one of these last week.

ARM DSO Nano - Pocket-Sized Digital Oscilloscope - eBay (item 200470598507 end time Nov-05-10 09:33:18 PDT)

The best real analog scope ever made was the 2465C, recently i saw a couple go for cheap.

Once you get into digital scopes, lots of stuff changes, and so does the real resolution which

is usually 8 or 9 bits. Also most of the digital scopes have limited voltage ranges.

I own both a 2465B, a 2465C, a 7000 series mainframe with plugins, the tektronix battery powered dso

and a 5ghz tektronix color dpo, and i like the 2465C the best.

Edited October 9, 2010 by kevin gilmore

[luvdunhill]

Kevin brings up a good point. 1Gs/s is an absolute minimum and 2Gs/s is probably where a DSO will start to compete more favorably with analog 'scopes mentioned.

[mypasswordis]

If I looked it up correctly, the max input voltage on the 2465 is the same as the 1052E (400V). I also saw somewhere mention 300V RMS for the 1052E. I think it's said that there should be a 10x correlation between GSa/s and bandwidth, so even if I hack it to 100MHz it should be good, right? But who knows just how much of a fall-off there is around the extreme frequencies, in comparison with the 3dB standard. Or if it'll throw everything off whack.

Thanks, guys, I think I'll keep doing a bit more research.

[Dusty Chalk]

Visit the physics lab department (3rd floor, IIRC), they were pretty open to nosy types when I went there (which, admittedly, was 25+ years ago). Also, the auditorium.

[kevin gilmore]

The 2465 is an analog scope, and does have a 400 volt rating (20 volts per major division)

In fact you can push it more than that in 1 meg input impedance mode by going uncalibrated.

(probably not a good idea for most people)

The digital scopes like the one i'm being forced to use lately (due to frequency) have a maximum

voltage rating of 5 volts per major division. Or 100 volts. But really much less than that because

the 50 ohm input impedance can only handle 5 watts peak.

Over the years i have stayed away from digital scopes as much as possible. What i need to

look at, and the way they work are incompatible. The worst ever are the LeCroy pieces of

crap. I have 4 of those. Not even heavy enough to use as door stops.

Agilent has a new scope that looks like it can do what i want. Stuffed the way i want it,

its $280K... No joke. Given the fact that i spent about $70k on a scope 25 years ago,this

is not actually such a bad price.

If i could find a real time analog scope with a 1ghz bandwidth i would buy it immediately.

Unfortunately, there is not now, and never was such a thing.

I'm going to be spending the next couple of weeks fighting a home build 65ghz EPR system

and know i'm in for serious amounts of grief.

Edited October 10, 2010 by kevin gilmore

[Pars]

From reputation, the 2465s are supposedly the best analog scopes ever made. They are also one of the Teks which have a proprietary IC in them that can go bad, rendering the scope useless. Only supply of said IC is a donor unit. And it may also be bad. Too bad Tek listened to their accountants and shut down their IC fab

[kevin gilmore]

Actually i think it is 4 of the chips that are proprietary. Lucky i have 2 trashed scopes with bad tubes for spare parts.

And now a 2467B that needs serious work. Nothing in this world lasts forever. All of the magic chips in the latest

tektronix and agilent scopes are completely proprietary too. And soldered to the boards, so if you blow the input

channel, you get a minimum of a $5k repair bill. At least agilent was smart enough to buy out triquint semiconductor.

[luvdunhill]

Kevin, I don't understand the complaint of restricted voltage input. Isn't that what readout coded high voltage probes are for?

[kevin gilmore]

It is really what i'm used to, and after doing the same thing for the last 35 years, i really do

not want to change.

10x scope probe on 2465 is 1600 volts peak to peak perfect for doing electrostatic work.

10x on my new tds5000 is only 400 volts peak to peak definitely not enough.

Not really fond of the 100x probes. And the 1000x probe is too big to be useful.

More to the point is that my other scope is 50 ohms only. And 10x 500 ohm probes

are a really bad thing to anything except low voltage RF.

[Kerry]

If you want interesting and cheap and new... I saw and played with one of these last week.

ARM DSO Nano - Pocket-Sized Digital Oscilloscope - eBay (item 200470598507 end time Nov-05-10 09:33:18 PDT)

...

Hi Kevin,

There is a new version of this coming out that looks pretty cool. Has two channels and will support 800V with the 10x probe. I think it also has a built in function generator. If you think it was worth it for the $43 version I may just try this $179.

Pre-Order

[luvdunhill]

Agreed Kevin. I think the DPO tech is a nice bridge between analog scopes and the entry level, earlier tech digital scopes. I used the same scope this week looking at DDR2 timings an it did everything I needed to do.

[kevin gilmore]

Yep that new $179 version is definitely something i'm going to have to have.

Way better than an iphone in the pocket... Well for what i need anyway.

i have the original tekmeter digital portable scope, and its great other than it eats

batteries alive...

[Pars]

Not sure if any of this would be of interest to you Kevin, just did a search on Craigslist...

HP3582A Audio spec an., HP8165A signal source, Hitachi V-423 o-scope

Also, are Philips scopes any good?

http://chicago.craigslist.org/wcl/ele/2008654797.html

Edited October 22, 2010 by Pars

[kevin gilmore]

That phillips scope is actually make by Fluke, i had one around here, and gave it away.

Its a nice piece of equipment that is built well and will last a long time.

The HP stuff is also a good deal.

[Kerry]

If I looked it up correctly, the max input voltage on the 2465 is the same as the 1052E (400V). I also saw somewhere mention 300V RMS for the 1052E. I think it's said that there should be a 10x correlation between GSa/s and bandwidth, so even if I hack it to 100MHz it should be good, right? But who knows just how much of a fall-off there is around the extreme frequencies, in comparison with the 3dB standard. Or if it'll throw everything off whack.

Thanks, guys, I think I'll keep doing a bit more research.

What was the result? Did you end up with a digital scope. Reason is I was thinking of getting the 1052E as well. Also wanted to check what the max voltage is with the 10x probe. Thx.

[mypasswordis]

The result is I ended up getting nothing. Realized I wasn't going to get a chance to even use it until last week (too busy) and then spent the money that would have gone towards an oscope on other stuff. The 1052E looks like a nice little unit though and if you get it I'd be interested in knowing how it is.