cheap old o'scopes or new pc scope?

[donradick]

I've decided that I need an oscilloscope.
Are there any features that are essential besides the very basic?

For my audio needs, I don't need a huge amount of features or bandwidth, and
an old one should work fine. Ebay has a number of old scopes, many for about
$50 with $25 shipping.

http://www.ebay.com/sch/i.html?_saca...temCondition=4

Or I could just use a PC-Based scope:

http://www.ebay.com/sch/i.html?_trks...at=0&_from=R40


Thanks in advance.

[Pete Schumacher]

Re: cheap old o'scopes or new pc scope?

Go with digital. You'll be able to save your traces to project files, etc.

[PWR RYD]

Re: cheap old o'scopes or new pc scope?

I really like my mid 80's Hitachi scope. I used to use Tektronics and HP scopes at work and they were both excellent. As Pete mentioned digital storage scopes are nice for trace storage but not a necessity for working on DIY audio equipment. Obviously you need at minimum 2 channels. 20MHz - 50MHz is more than enough bandwidth. Make sure that whatever scope you buy comes with both scope probes. I bought mine off Craigslist ($65), so I was able to power it up and demo it before handing over the money.

I have zero experience using PC based scope hw/sw.

[Pete Basel]

Re: cheap old o'scopes or new pc scope?

I'd go with a used Tektronics with 50 MHz bandwidth minimum if you plan to work
on amplifiers and general electronics.
Don't like Digital scopes and I've used $50K Tektronics models.

[LIDAR]

Re: cheap old o'scopes or new pc scope?

Digital scopes do offer the advantage that you can store traces, but they also have one major drawback. They lie to you like a skilled politician. Analog scopes can fool you sometimes as well, but normally you can see when there is some nonsense going on.

I have dozens (maybe hundreds) of scopes I can use at work. My standard go-to for first measurements is an old Tektronix 7600 series boat anchor - with appropriate plug-ins, of course. It will tell me in just a few seconds if what I am looking at is for real. Then I can break out the digital scope if necessary.

BTW - the scope I bought for home is..........a Tek 7600. I paid 50 bucks at the MIT flea market. It needed a little cleaning and alignment, but it worked OK even before I did that. I'll probably keep that scope until I die. Digital scopes will come and go....

[tyger23]

Re: cheap old o'scopes or new pc scope?

I personally don't like PC scopes. For some reason, I've never found them to work as well. Plus, you have to have a PC near your workspace at all times. If you have the physical space to fit a full-blown O-Scope, then go for that. The old analog I used to use was a TEK 2225. Great unit.

To me, I would stick with a Tek no matter what unit you buy. They are common, easy to find and replace, and darn near bulletproof. Good luck.

[hongrn]

Re: cheap old o'scopes or new pc scope?

Hey Don,

Go for a digital scope that has a PC interface. Some of them cost less than $300 brand new. For what we do, we don't need a lot of sophistication, but a used analog scope is very difficult to read for noobs like me. I had a old Hitachi that was donated to Jon Pike for that reason. For example, on a digital scope, you can read volts and millivolts on the screen versus having to count the lines on the grid. Go with the technology man.

[donradick]

Re: cheap old o'scopes or new pc scope?

Thanks for the tips guys!

Wow, not developing a consensus here - maybe I should have created a poll?

Leaning towards an old Tek - I had a really old HP scope at one time - what a workhorse.
Let it got for $50, and of course now I need it....

[marscoast]

Re: cheap old o'scopes or new pc scope?

About 3 years ago I bought a Hantek USB DSO oscilloscope (I think it's the 2090). I don't use one often, so didn't want to spend a lot. It's been great so far.

[AJ]

Re: cheap old o'scopes or new pc scope?

For your first oscope, stick with analog. An old Tek, HP, Leader, Hitachi, Philips, etc... will do fine. You want something solidstate (no tubes), 2ch or more, 15Mhz or high bandwidth. Tektronix 2215 or 2225 would be perfect. Look for one that isn't beat up or dirty, and has been calibrated in the last 10 years or so.

Digital oscopes are fine but the good ones are expensive. No need for analog audio work, although the measurement and math aids can make testing go quicker.

For new, the go to entry level digital is the Rigol DS1052.

http://www.rigolna.com/products/digital-oscilloscopes/ds1000e/ds1052e/

[donradick]

Re: cheap old o'scopes or new pc scope?

For your first oscope, stick with analog. An old Tek, HP, Leader, Hitachi, Philips, etc... will do fine. You want something solidstate (no tubes), 2ch or more, 15Mhz or high bandwidth. Tektronix 2215 or 2225 would be perfect. Look for one that isn't beat up or dirty, and has been calibrated in the last 10 years or so.

Digital oscopes are fine but the good ones are expensive. No need for analog audio work, although the measurement and math aids can make testing go quicker.

For new, the go to entry level digital is the Rigol DS1052.

http://www.rigolna.com/products/digi...1000e/ds1052e/

Thanks AJ - I'm stronlgy leaning towards a Tek 2215 or 2225 at this point.

Man, that Rigol looks good!

[msibilia]

Re: cheap old o'scopes or new pc scope?

Have a quick look at this before you decide:

https://www.kickstarter.com/projects/751733865/smartscope-reinventing-the-oscilloscope

100Msample/s dual channel, iPad, Android, PC. About $200.

Marc

[Whitneyville1]

Re: cheap old o'scopes or new pc scope?

Another "throw-away" is my Tektronics 2235 from then Memorex/Telex before Verizon "Borged" them. They had 4 or 5 dumpsters full of good working 'scopes that didn't have enough bandwidth for fiber-optics. First grab, first serve. I got one with the HV probe, the HF scalable probe and a calibration standard, free. "Why didn't they sell them?" Possible mercury, carcinogens, yadda, yadda, yadda they didn't want the liability for. Circuit boards may be soldered with lead based solder. My used PC "pusher" has Toshiba flat panel CRT monitors and NEC plasmas. Two year unconditional warrentees. They came from Blue Cross and Blue Shield and a Mega-Mortgage Co. $60 each. Not RoHS stickered. You have to sign a Federal paper saying they won't be used by minors to buy them. The plasmas are about 30-32", and the Toshibas are 10x16 format 26". If you buy a re-furbed 'puter from him, he'll throw-in a 26" CRT free. They're big and weigh two-tons but they're still good. Most of this stuff now goes out of the US, still working, as scrap for the rare earths, silver, gold and platinum in them, where little kids in Mexico City's dump, or China, or Malaysia, or a dozen other countries, break this stuff up and dump it into vats of potassium cyanide to reclaim the "good stuff". The "not so green" side of recycling. Hey, it can be done safely, just "not in MY backyard".

[weinstro]

Re: cheap old o'scopes or new pc scope?

I've decided that I need an oscilloscope.
Are there any features that are essential besides the very basic?

For my audio needs, I don't need a huge amount of features or bandwidth, and
an old one should work fine. Ebay has a number of old scopes, many for about
$50 with $25 shipping.

I use a portable Tektronics/Sony scope with ~25 MHz bandwidth. But, alas, it arrived with one channel inoperative.

I also use a Heathkit scope with about ~5 MHz bandwidth. For most audio work, this is probably fine. For SMPS development, it might miss oscillation.

Main essential feature would be the ability to have a differential mode and an XY mode to display things like a Lissajous. I have some amplifiers where "optimal" bias setting requires a Lissajous.

For digital, the ability to store and the ability to read peak voltages and frequencies right from the display are sweet. However, for PC based, you should look into differential measures and probes for higher voltages. Straight in probably won't take more than 5v.

The real charm of the PC-based approach would be portability (laptop). The next logical evolution of that thought is using a tablet or iPad as the "scope". This would be the ultimate in portability, but you should evaluate this against other handheld o-scopes and the probe question is still posed.

Regards,

Rob

[Pete Schumacher]

Re: cheap old o'scopes or new pc scope?

What I meant by being able to store the traces is that because it's on the PC, you can take screen shots and paste them into project write ups, etc.

100MHz sampling rates are more than adequate for doing audio related stuff, including amplifiers, preamps.

Old style is good too, just not as easy to transfer the information to other platforms.