recommendations for USB oscilloscope?

Thread Starter

rick5

Joined Jul 17, 2008
12
I need a scope for my own circuit design, prototyping and build work.

I would describe most of my stuff as analog or sometimes mixed signal. At the moment I've got a handful of analog circuits I want to finish. For those scope bandwidth is not important to me, but I'd like good voltage level accuracy with at least 8 bits quantization in the ADC.

Next up I've got some analog work in the general audio frequency range and I reckon I'll need at least 2 channels.

A spectrum analyzer facility would be great as I'm also doing some very specific guitar eq circuits, so it would be great to look at the spectrum produced by certain types of guitar playing and design for that.

I've got some FM transmitter circuits in my head too, so i reckon 100Mhz bandwidth would be nice. If a scope has a bandwith of 25Mhz and it does one sweep in that period, I reckon you can still get a good look at waveforms of up to 100Mhz?

So far I've looked at Bitscope, Picoscope and some Chinese brands. In fact I saw some enterprising people on ebay who've made simple low bandwidth USB scopes from a Microchip chip and selling them at good prices. I would consider buying a kit or making my own from a schematic.

What do you think I should get? I like the look of Bitscope but it's a bit expensive, it's even got an 8 channel logic analyzer facility.
 

thatoneguy

Joined Feb 19, 2009
6,359
I had been using a 25Mhz Phillips for 10 years, and was far out of it's range (and calibration).

After looking over the options, I ended up buying another analog scope, Tektronix 2445 (150Mhz). It has cursors, but isn't a storage scope. It is capable of 90% of what I "need" to see, and about 60% of what I "want" to see. (Time/Level/Frequency Measurements, No Math, only 50Mhz effective, no digital signal decoding).

Used Tek 2445, calibrated, on a good day is $250, about the same as a new USB scope. My other option would be the WaveAce Series from LeCroy, or the Entry level DSO from Tektronix, both around around $1k, and offer 1GS/s, math, etc. Either way, you don't need to tie up your comptuer/have access to mouse and keyboard when hacking electronics, although it is an option with the DSOs mentioned.

The new "Entry Level" thousand dollar scopes (retail of $1k) do about everything and more than a mid-range ($10-15k) scope of 10 years ago. They also have USB ports so they can be controlled and displayed on PC, print to USB Printer, save screens to a USB Stick, etc.

Stay away from the OWON and other < $500 DSO's New. They are all over eBay. They look good "on paper", but performance is like "a broken 10KS/s 40Mhz digital scope from 1998", according to one person expressing their feelings after buying/using one. He went back to his analog.

My advice: If you can save up $400 for a good USB scope, keep saving and shoot for $1k to get the standalone Tektronix or LeCroy new w/Warranty. They have incentives for students and other offers from time to time, check out the company home pages, I was amazed!

http://www.lecroy.com/tm/products/Scopes/WaveAce/default.asp LeCroy WaveAce (most all other LeCroy have a 5 digit price tag)

http://www2.tek.com/prodcompare/index.jsp?p=TPS2000 TDS1000B-TDS2000B&data=scopes_en Tek TPS and TDS Series.

For channels, hour wise, I am at about 50% 1 channel, 48% 2 channel, and rarely using 3 or 4.
 
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