Digital Oscilloscope, which one?

[Pryde]

What about this one, OK? Seller fixes and tests them with 14 day return policy and includes 2 new probes.

Tektronix TAS220 Dual Trace 20 MHz Oscilloscope Read Out Two Probes Power Cord | eBay

[gbono]

HP54603B - Very good series of scopes from back in the day. I bought one off ePay for under $250 with case/probes. This is a 60MHz model which should easily cover all your needs unless you are trying to find the jitter in a 28 Gbs transiver

[Jazz P Bass]

I have a Tektronix TD320 digital scope.
It is awesome.

[Jazz P Bass]

I do have an ancient Bell Howell (Heath) IOD-203-31 for sale.
It is a 'school' scope, I guess from the late '70's.

It works great.

A little finicky to adjust, at first.
I practiced on a signal generator.

[g1]

What about this one, OK? Seller fixes and tests them with 14 day return policy and includes 2 new probes.

Tektronix TAS220 Dual Trace 20 MHz Oscilloscope Read Out Two Probes Power Cord | eBay

Judging from the feedback, seller seems reputable. Can try lower offer. Seller also has quite a few other tek scopes for sale.

[Pryde]

Thanks jazzpbass. I may hit you up on that scope but need to follow through with a possible local find. My wife is a prof at a local collage and got me in contact with the electronics instructor there who said he has "tons" of equipment (variacs, oscopes, signal gens, etc) so maybe I will get lucky and score some goodies. Will update.

[Mick Bailey]

When looking at a used scope (especially Tektronix) you need to make sure all of the knobs and switches are present. Some of these are very expensive to replace - even if you can find them. Don't get too hung up on whether its recently been calibrated or not. We're mainly concerned with viewing signals rather than taking lab measurements and so long as the internal amplifiers and timebase circuits are working as they should an uncalibrated scope will be pretty close anyhow.

Take a general look at the condition. If it looks damaged or abused, find another.

The display is important; check that the trace isn't burnt into the phosphor - it will have a ghosted line if it is. Some scopes are left on all day long with the brightness turned up. With the scope switched on try the brightness control - you should be able to go from nothing to very bright. If the brightness won't turn down it points to an internal DC restorer problem - tricky to fix as the high voltage caps are often hard to get hold of. Also, check the focus works correctly and the trace positioning controls operate correctly.

You can get a waveform displayed on most scopes by hooking the probe onto the CAL point. You get a square wave off this which is a rough check to make sure the amps are working.

The College lead is a good one. I got over 1/4 Ton of top quality equipment from a University clearout. All the best quality stuff, all working 100%.

[soundguruman]

I want to get a scope for repair work. I know many use and suggest old analog tektronics, etc. but I want something small that will run with my computer so I have narrowed it down to 2 which seem to be able to do basic amp diagnoses from my understanding.

Picoscope 2204
PP419 - PicoScope 2204 - $262.35

or

Hantek DSO-2090 USB
http://www.amazon.com/Hantek-Based-D.../dp/B0036FZRU4

The picoscope has a function generator where the hantek does not. Is that worth the extra $80 or so dollars to get it?

I just want something simple for basic/common amp repair and building work. Looking forward to your responses. Thanks.

Picoscope is pretty cool, if you are going that route..
I hate digital scopes, overall. I would rather have Tek 465.
The college where I go for classes has all kinds of Tek digital scopes. They really are a pain ITA, compared to analog scopes.
As far as speed and user friendly performance...

[silverfox]

Used Scopes

Spell check off. BTW, is there a spell check on this site??

Anyway, about two years ago I bought a used Tek 422 for $20.00. Worked fine but I could see where it was going to need some work on the inputs. The schematics are readily available, (don't pay there is a Tek user site out there and I downloade the one for my scope free). I ended up selling it for $40. and I was surprised at how quickly it sold. Now I've got a like new BK that was purchased in the 90's and never used. Paid $40. Works great. The schematic was included in the manual.

Check craigslist and bring a function generator, allow the scope to run for a while. Lots of good test equipment as well as Ham radio stuff going up for sale now that the Old Guru's are moving on to- Where ever it is old Guru's go when the electrons stop moving.

Silverfox.

[Mick Bailey]

Picoscope is pretty cool, if you are going that route..

You're kidding?

10mhz bandwidth - divide that by two if you use both channels - a dual 5 meg scope for the 21st century?
+/- 20v input range
100v input protection limit

Terrible waveform rendering at higher frequencies.
Flaky triggering


Ok - it's better than nothing. I say any 10 meg analogue scope will hammer it.

[gbono]

The local junior college here sold off pallets of gear since they cut their technician certification program - no need for the program since local manufacturing jobs moved to Malaysia.

You can also find the occasional sale on craigslist where a wife/family is selling the gear of an old ham who became a "silent key" - sad.

[Gregg]

So what's the deal with the "Oscilloscope Shop?" All their equipment listings just link to eBay auctions.

That's exactly the deal - all scope listings in one place.

For measurements in the audio range I think even a 10Mhz is too much and it depends what you're really measuring. If you just want to see the wave form, clipping etc. you can do that for less than 100$.

[km6xz]

I like scopes and used to pick every Tek scope I could get for a deal. There are few scopes that last as long or handle as much abuse as a Tek 465b but one that costs less, about 30-50% less, that is more rugged and runs cooler: The often maligned Tek 465M which was a ruggedized version that used a lexan case instead of the normal thin aluminium of other models. Test gear hobbyists rejected them due to that "plastic" case. It has no fan, because all the heat generating devices are mounted on the interior surface of a ribbed rear heatsink. It is silly because it is really tough . The only scopes I brought with me here was the Tek 2236 and a 465M since I was concerned about it traveling in my suitcases and baggage handlers making their best effort to destroy and luggage.
The 2236 is a great tech scope due to its integrated digital display for frequency, voltage, temperature, ohms, time, delay sweep offset with a high accuracy TCXO time base. The digital multimeter gets its input from switch selected Cha 1 probe input or side panel test lead jacks. The cool thing about the frequency counter is that is has a very fast sampling time for low frequency signals so a 10 hz signal can be displayed in a fraction of a second. A normal high res frequency counter takes a long count period for high resolution on LF signals. I bought that one new from Tektronix in the late 80s for $3600 and it has been flawless.
The 465M was picked up for $75, and had a current calibration sticker. I use it primarily for the burn-in bench but it is, like all Tek scopes, a joy to use, solid triggering on signals that can hardly be seen and accurate delayed sweep. I would suggest anyone who intends to use a scope daily for a long time, forget the fragile Chinese digital scopes and get a real scope for less, like $75-150 for a 465M. Check with the local ham radio club, they always have a list of widows who are trying to sell their dead husband's collection she thinks is junk. Or go to the radio swap meets. eBay has driven up the price for junk as well as better gear so less of a good deal can be expected.

[Tom Phillips]

An additional advantage that real analog scopes have over those such as the PicoScope is that they have real physical controls. You have rotary switches, pots and buttons available to choose your settings. I know that some people will say that's old fashioned and unreliable (maintenance issue). However, it makes them a joy to use and understand. The difference between that and a modern scope with a GUI is similar to the difference between playing a real instrument vs. programming the music on a computer.
My opinion anyway.
Cheers,
Tom