Choosing an Oscilloscope

If you're considering second hand then £1000 will buy a very good scope tektronix 100+ Mhz with all you could possibly want on it on ebay!!!

In fact £500 would be sufficient to get a really good scope on ebay.

If you're buying new then you are more limited...

It depends on what you mean by analogue and digital signals, if you mean you will be checking rise times and delays of dicital signals up to 40 MHz then you will really need a 200+MHz bandwidth to capture and measure the edges etc...

If you are looking at very small analogue signals you will need the sensitivity, if you're concerned about the shape of the waveform at 40 to 50 MHz then you will need a bandwidth much more then 100 MHz for the analogue....

I use a Philips digital storage scope mainly as I do low speed work so the rolling 50 second per division digital storage is a great help. But at 20 Msamples a second it not much good above 10 MegHz... But a nice thing about it if I'm not sure whether I'm getting aliasing is that a push of a switch allows me to switch between anolgue and digital storage mode...

I'm afraid a lot more information is needed to answer your question with any degree of certainty...

Maybe you could ring a few companies and get a demo unit to play with for a few days, that is always the best way to select something....

John.

I would suggest a scope that comes with a good name tektronix for example, buy on ebay, I use special software to allow me to bid low on many simultaneously, that way I generally get a good price!

Use it, if it is not good enough, sell it on ebay, you will get usually most of your money back unless you bought stupidly! And with your better knowledge, buy the exact one you need!!

http://cpc.farnell.com/jsp/search/browse.jsp;jsessionid=25J0BD3FHITJVQFIAFAZKBQ?N=411+1001695+5194&Ntk=gensearch_003&Ntt=oscilloscope&Ntx=&_requestid=327904

I hate the user interface on the bigger Tektronix scopes but they have got it right at the lower end.

As john says think about what you mean when you say you want to measure digital signals: I spend a lot of my time looking at the analogue details of digital signals. But you can get MSOs (Mixed Signal Oscilloscopes: incorporate normal scope type functions and logic analyser type inputs) at this lower end of the market.

Basically you need to consider:

1.) How many channels do you want/need. (Analogue and digital if you're looking for an MSO)

"HORIZONTAL SPEC"

2.) Analogue bandwidth.

3.) Samples per second: single shot and sampling.

"VERTICAL SPEC."

4.) Analogue resolution.

5.) Digital resolution.

OTHER

6.) Triggering facilities

7.) Analysis facilities. This consideration may well push you down the route of a PC add on.

8.) Can you easily get data and screen dumps onto a PC.

Again as John said don't be afraid of the second hand market (but consider 8 above).

Most big names should have a scope selection guide on their sites.

ya can get an older Tek 465 cheap, about $300 to $500 in good condition and with two probes. I have two, a 465 and a 465B, and a Tek 2467B. One can never have enough O-scopes with good probes. a site for info, but not for price, ya needs to look for cert o-scopes http://www.testequipmentdepot.com/usedequipment/tektronix/oscilloscopes/tek465&465b.htm

I agree with everyone above. An old but great Tektronix 465, (100 Mhz), is just the cat's meow. Also Phillips, Hitachi, and Hewlett Packard, make or made great scopes.

I would just go for one of the older Tek scopes, they are SO!!!! beautifully built, and cost many times the price you can find them for today.

Geoffrey

my Tek 2467B cost once $10k easy, now in good condition maybe $2.5k. The 465,s are heavy if ya got to carry it around alot, but they don't seem to go bad. The 465B is just an add on meter to the scope, never really used it, had Flukes DMM for that.