I just want to do the standard experiments and circuits that you learn in engineering school. What oscilloscope should I get? Is used off ebay ok?

Thanks

 

I just want to do the standard experiments and circuits that you learn in engineering school. What oscilloscope should I get? Is used off ebay ok?

Thanks

Personally, I like the old Tektronix analog scopes. You can find them used on Ebay. There are many variants, like the 2235. Look for working ones with some type of guarantee from a reliable seller.

There is always the risk of failure with old equipment, but those old Tek-scopes last well; and, on the rare occasion you have to fix them, it's a good learning experience - Or at least, so I'm told. I've never actually had to fix one. I have 3 that have never failed, although one is now a little out of calibration.

 

The scope I use at my home lab is the OWON PDS5022 I picked it up NEW with warranty for $280 delievered. It is a 25MHz digital scope with a 100MS/s sample time. Very slick for the money. OWON is made by Lilliput a rather well known company.

afrotech has a good tutorial on if, why and where oscilliscopes.. and he uses my same scope in his videos:

http://www.afrotechmods.com/groovy/oscilloscope_tutorial/oscilloscope_tutorial.htm

Good quick education.

 

if you read the many posts here about the purchase of used scopes you will hear horror and love stories.

it depends on your budget and how far you want to take it.

if you are in the field for the love of it or on the persuit of a degree in this field...please make the investment up front in a good scope. either used or new. dont waste the time and money on a "beginner" scope.
as steveb says, it is hard to go wrong with a Tektronics. but others are just as good.

e-bay is ok, I buy 20 to 50 old antique or out of production o'scopes per year through ebay and rebuild them.
only a couple were so bad that they could only be cannibalized for a few good parts.


but try this:
Many of the sellers on ebay that specialize in electronic gear will have a store front, garage, shop or basement they sell out of. Ask them via a message.
Find a local one. I found one up the road in Eldersburg and what I save in shipping costs is enough to purchase the parts for many of the repairs I do. Especially all the electrolytics I buy! This way you can try it before you buy it. Easier to get your money back also, or trade up. They will work with you.

 

The scope I use at my home lab is the OWON PDS5022 I picked it up NEW with warranty for $280 delievered. It is a 25MHz digital scope with a 100MS/s sample time. Very slick for the money. OWON is made by Lilliput a rather well known company.

afrotech has a good tutorial on if, why and where oscilliscopes.. and he uses my same scope in his videos:

http://www.afrotechmods.com/groovy/oscilloscope_tutorial/oscilloscope_tutorial.htm

Good quick education.

That seems like a pretty good deal. Does the PDS5022 come with any warranty? Also the site says it comes with "accessories"--leads, or what?

Thanks

 

Yes, it is a two channel scope and supplied with leads for each channel. It is very quick and has very sensitive trigger modes and auto measurement modes for channel to channel or you can plug it into your pc via USB and use software based systems like function generation and logging. The autoset and autoscale are invaluable as well as the ease of use. The resolution is excellent. Ive used a few analog scopes and a few digital scopes, and for the money, I couldn't see spending more on less. You could buy a used scope for more money get less options and not get the warranty. (Yes it has a full warranty.) The scope includes live oscilloscope logging software and drivers. You can even use the scope as an input for other O'scope software.
I am very happy with this purchace.

 

retched,
nice scope!
http://www.tequipment.net/2009/06/unsolicited-customer-review-on-owon.html
i wish that would have been where the field was when I entered.

attached here is a used (obviously) HP1740A 100MHz I got through ebay for under $40.00USD. I have not done anything to it yet in the way of calibration or repairs. it works well.

also are a couple screenshots of an entry level Velleman PCSU1000 http://www.vellemanusa.com/us/enu/product/view/?id=522377
PC based scope about the same price as the Owon. nowhere near as portable being you also need a PC to use it. it is 2 X 60 MHz and comes with all the leads and options.

you have a lot of choices and options.

 

Voodoo,
And I wish I would have seen that auction for that HP..

I am very happy with the performance of the OWON, BUT... I would love to have a nice analog CRT for the home lab.. and 100MHz for $40 would have been beautiful.

Nikola,
Whichever option you choose for a O'scope, be it PC, analog, or digital, something is better than nothing. if you can get a 1 channel 5MHz PCbased scope for $5... do it. It will open up a new world to you.

and, ultimately, after you have the wave, the only other things you are paying for is convenience. Mine has many measurement and display options that do a bit of math for me. I like having those numbers onscreen, instantly.

Also, build yourself a function generator (or buy one), to really get yourself excited about moving along.

 

indeed retched!
attached here is the first scope I ever owned. Eico 435. not the exact scope because that one had been cannibalized years ago. This is one of those 5 dollar scopes you eluded to. I picked it up on ebay for nostalgia reasons. It works fine.

The original I bought as a kit when I was in high school electronics class.
1966. I had it for so many years, mostly used for automotive/motorcycle applications after outgrowing it after high school.

You will never really know what is going on in a circuit without a scope.



go Ravens!

 

I am very happy with the performance of the OWON, BUT... I would love to have a nice analog CRT for the home lab.. and 100MHz for $40 would have been beautiful.

I think this is an important point. There are benefits to both types of scopes, and there is a good arguement for tracking down cheap versions of both scope types, if you want to have the best capabilities.

I use a digital Tektronix scope at work which has a look and feel of the OWON you highlighted. At home I use my old analog scopes. I find that there are cases where one is preferred over the other, and ideally it would be good to have one of each.

I can't justify spending $2000 for a modern Tektronix digital scope for home use, but that Owon would be something I would consider to augment my home capablities.

Just to give some simple examples. The Owon would be preferred for capturing quick transient signals or for seeing very slow, low frequency signals over many seconds. The old high speed analog scopes are amazing pieces of scientific equipment. You can measure the speed of light over the distance of a few feet right on your table top.

So, both is best. However, if only one is an option, I think the Owon might be preferred by most young people doing hobby and home work, but some of us old-timers might prefer the nostalgia of the analog scopes. Hearing and feeling the click of those old clunky knobs gives me the same joy as those first odors when I turn on the soldering iron. Both evoke a great many of good memories.

 

Make sure you guys regularly check craigslist. I see a couple a month sold locally on there. Usually 90% of the time someone got it in an estate sale of closeout auction and knows nothing about scopes. You can usually call them and they will let you test it and see before you buy. They are so heavy most don't want to ship and prefer CL over feebay.

 

I went with the OWON PDS5022. I feel bad about spending that kind of dough, but the dusty analog scopes kind of freak me out.

Forgot a function generator...thoughts? This one looks good to me:

http://cgi.ebay.com/Topward-8140-Fu...emQQptZLH_DefaultDomain_0?hash=item3358f51537

Thanks for the advice, all

 

specs for the generator:
http://www.spencetek.com/fg/fg_8140.htm
10MHz

and heres what the go for new at one place.
http://www.calright.com/pd_288.aspx

 

Don't feel bad. Once you hit that power button for the first time, It will subside.

When you solve your first problem with it, feeling bad will turn to excitement.

Totally WORTH IT. Even for the education alone.

 

Dumb question...can you get DC voltages out of the Topward 8140? Like to power an op amp? I am trying to remember how we did this in the lab, and it escapes me.... I guess what I'm asking is if you can get +16 and -16 V (DC) out of the topward 8140. Thanks.

 

yes, square wave. But I think the 8140 maxxes out at +10/-10.

here is the specs:
http://www.spencetek.com/fg/fg_8140.htm

 

? confused.

You power an op amp with a square wave? I thought you just used +16 and -16 V sources?

 

You could rectify & filter the sq. wave for about +_ 9V @ low current.

 

Is there an inexpensive function generator that has, say, +20 and -20 V of dc voltage?

 

I see I will have to get a separate power supply.

My question is: how are op amps usually powered? I sit +16 V on the upper side, and grounded on the lower side? On diagrams I usually see -16 V on the lower side, but none of the power supplies I'm looking at give negative polarities. What gives?