Oscilloscope recommendations

[charliex]

I'm really happy with my TDS 2024B too, great scope.

[mojo]

What worries me about Rigol is that they have open-sourced their firmware

That would be very interesting, Can you provide any URLs?

My apologies, it is WELEC who have open sourced their firmware.

Such as? I'm not challenging what you are saying but I'm trying to make a buying decision, so I'd like what ever specifics I can find. From what I've read, the logic analyzer option for the scope had a bunch of problems. I've recently tried to comb through the 50+ pages at rcgroups and the 14+ pages at eevblog and I didn't really come away with that impression other than the logic analyzer issues. Maybe I didn't understand enough of what I was reading.

Well you mentioned the two biggest sources of info on the issues. The LA is problematic but people also report issues with the FFT for example (on those forums). It's not as bad as the WELEC where it appears the display is off by a factor of 2 (!) but it certainly seems like it took them a few firmware revisions to get it right.

The latest firmware does seem to be a lot better. That is if you can figure out which one it is, as there seems to be a lot of confusion over that too. It seems that different regions web sites have different firmwares, plus different model names and numbers.

Anyway, I ordered the Instek, will report back on it next month when I have had a chance to play with it.

[sirket]

Anyway, I ordered the Instek, will report back on it next month when I have had a chance to play with it.

Please keep us posted on your experiences. You may even want to start a new thread to document your impressions and experiences working with that scope.

[threecharacters]

My experience with Rigol and GW Instek support contradicts that of sirket.

Rigol: Horrible support, usually useless answers

I bought online on eBay, and apparently Rigol hates customers who bought online and not via an official distributor with inflated prices. Every time I contact Rigol support I have to run through some Q&A ritual, just to be told at the end they can't help me. Whatever I do, I always end up at the same support person, and I really tried hard to find someone more helpful. Very annoying is also Rigol's habit of declaring models as obsolete when they no longer want to maintain the PC software. "obsolescence" is at least their standard explanation for lack of Windows 7 software for some models. See below regarding Linux software.

GW Instek: Acceptable support

Here I bought via an official distributor, since distributor and Internet prices were almost the same. Ironically, GW Instek support never cared about where I bought. Owing a GW Instek oscilloscope was good enough for them to help me. With their support I always have the feeling they at least honestly try to find an answer. Not always successful, but they try. A few times my requests ended up at the wrong person, but a quick reminder fixed that.

Similar with using them under Linux:

Rigol: A mess to get it working under Linux.

The usbtmc kernel driver doesn't work for me. It always fails already when trying to open the device. The Agilent kernel driver doesn't work, because it uses old internal kernel interfaces no longer supported. The openmoko libusb driver? Well, after I used it as a model to write my very own driver, I have a libusb driver working 9 out of 10 times. Sometimes the instrument's USB port locks up, requiring to cycle power.

GW Instek: http://code.google.com/p/gds2000tools/

It takes some fiddling to get gds2000tools installed, but then it does its job. Sometimes I have to fiddle with some of the scripts, because they are apparently written for another oscilloscope mode. But overall, it just works.

[Entropy]

I bought online on eBay, and apparently Rigol hates customers who bought online and not via an official distributor with inflated prices.

Google "grey market"... You'll have the exact same thing when purchasing camera equipment from non-legitimate channels. If you want U.S. warranty support, you need to buy from a U.S. distributor, not a Chinese one.

(I bought from Saelig in Rochester for just this reason - to ensure U.S. warranty support and make sure I didn't get one of the "factory quality control rejects".)

Very annoying is also Rigol's habit of declaring models as obsolete when they no longer want to maintain the PC software. "obsolescence" is at least their standard explanation for lack of Windows 7 software for some models. See below regarding Linux software.

Rigol: A mess to get it working under Linux.

The usbtmc kernel driver doesn't work for me. It always fails already when trying to open the device. The Agilent kernel driver doesn't work, because it uses old internal kernel interfaces no longer supported. The openmoko libusb driver? Well, after I used it as a model to write my very own driver, I have a libusb driver working 9 out of 10 times. Sometimes the instrument's USB port locks up, requiring to cycle power.

This is not Rigol's fault, it's a Linux flaw that the mainline usbtmc driver sucks. At least you don't have to depend on the manufacturer maintaining software.

I've had no problems with the Agilent driver, although I didn't get it directly from Agilent's site (was down at the time) - the place I got it from might have ported it to newer kernels. I'll try to find the link... Somewhere on github. (Fairly certain it was http://github.com/imrehg/usbtmc )

As to lockups - I've never seen this happen. If you give it a bogus command bad things will happen, but that's what the reset ioctl is for. I have never had the instrument go into a state where this ioctl failed to get things back into a sane state.

[mojo]

I have been playing with the GW Instek scope and so far am pretty impressed.

Every just works as you would expect it to. The disable update is fast and the controls are responsive. Saving to SD card works fine, including CSV export of the raw trace data which is very handy. The unit is solidly built but not heavy and the screen is bright with a wide viewing angle. The manual is comprehensive and the quality of the language is good (no dodgy translations).

I will post more when I have used it for some real debugging. I have some digital control and radio stuff to look at.

A note on the package. It came with two probes that have a selection of clips/connectors and a calibration certificate. The only thing missing was a BNC-BNC cable for re-calibration, so I picked one up for about ¥350. I have not attempted to re-calibrate as it seems to be spot on (as you would expect being new). There was a complementary SD card reader which I have not bothered with as I already have one, but no SD card. I tried a 1GB MicroSD card in an adapter and it worked fine.

[rct]

I got my Rigol DS1052E within the last week. So far I'm very happy with it. Full disclosure, It's the first scope I've owned so there maybe things I'm unhappy with later.

I'm using it under linux, so far with just the default tmc driver that came with the 2.6.31 kernel. I can do simple things like cat ":MEAS:VPP?" > /dev/usbtcm0 ; cat < /dev/usbtmc0. (When EOF is reached the device closes with a connection error, I'm not sure if that's the right behaviour for tmc or not). However, it's been trivial to write tiny perl scripts that gets the data out and does useful things with it. (I also tested that the plain old RS-232 connection works without a hitch on a real serial port or an FTDI usb<->serial adapter.

I haven't been able to get the openmoko libusb tmc driver to compile for the python stuff yet. I think it's written for an older version of libusb. I'm not sure though that I actually need that driver. I think I can use it with the default tmc driver or the agilent one.

As far as software goes The DS1000E/D and DS1100E/D don't have the same USB quirks that the older C models did so it works with more software as is. I'm guessing from what you've posted you must have (or had) an older C model.

I have however been able to send commands via that will cause the scope to lock-up with garbage on the screen. Usually this is from trying some of the undocumented commands like waveform points maximum when in run mode instead of stop.

[sirket]

Mojo and RCT:

You guys should definitely start new threads about each of your scopes. You could include specs, pricing, impressions, etc. Long threads stop being useful to people if they have to slog through numerous pages and the information you guys are providing is too valuable to have it end up buried deep in a random thread.

[rct]

You guys should definitely start new threads about each of your scopes. You could include specs, pricing, impressions, etc. Long threads stop being useful to people if they have to slog through numerous pages and the information you guys are providing is too valuable to have it end up buried deep in a random thread.

I have to say I'm very grateful for finding this thread in this forum (and a few other threads in other forums). A few weeks ago, I was close to buying a USB oscilloscope like the propscope because I thought a decent dedicated hardware scope would be closer to $1 - 2K. I'm pretty sure it was here first that I saw a recommendation for the Rigol DS1052E with a mention of an approx. $500 price. I'm very happy to have bought my first hardware oscilloscope. (I was using the soundcard before). I've solved a few problems already and I think my understanding of a bunch of things got a lot more solid in the week I've been playing with my new toy.

I'm also happy to know there are non-Rigol alternatives like the Instek that people seem to be happy with.

Sirket, your point about long threads is well taken. I prefer wiki's to forums myself. I've posted some summaries of what I've learned along the way in a few messages here, and in the RC group forum to help others. (I scanned a lot of the almost 60 pages of rigol scope thread on the rc group forum before buying.) I'm not sure if there would be a lot of value to starting a new rigol & instek thread. I certainly wouldn't want to see any my scope is better than your scope wars.

One of the things I'd like to see is what usb tmc software would be compatible for both scopes (or as many scopes as possible). I'm mostly interested in linux.

[rct]

For those people with Rigol DS1052E 50 Mhz scopes, the software only hack to upgrade it to 100 mhz bandwidth has been covered in the latest EEVblog entry.

* http://www.eevblog.com/2010/03/31/eevblog-70-turn-your-rigol-ds1052e-oscilloscope-into-a-100mhz-ds1102e/

Discussion has been going on for a while in the EEVblog forum:
* http://www.eevblog.com/forum/index.php?topic=30.270

(of course you do this at your own risk, void your warranty, etc. etc.)

There are some reports that future versions of the firmware are starting to appear that disable the "feature" that permits performing the model/serial number upgrade, which is entirely expected given the publicity.

[didier]

a-w-e-s-o-m-e ! Makes sense in a production point of view. I saw that in the past on high-tech instrumentation. But the upgrade required few hardware changes just to justify the change in price.
I ll try it asap. Has anybody run a test on FFT after the mod?

[didier]

And it works! For some reasons the first attempt failed to work (no model, no SN# in the system info ) . Second attempt was alright. Awesome.
My guess is that the worst case testing is the FFT, and it proved to work perfectly (except that I discovered that you cannnot send a moving cursor on the frequency spectrum, but this has nothing to do with the upgrade ).
Now, I'll open the ECU from my car and try to change a couple of digits to uprate it to twice its power

[sirket]

Now, I'll open the ECU from my car and try to change a couple of digits to uprate it to twice its power

Let us know how that works out

[mazatta]

I found someone locally who is selling a used Hitachi v-212 20 mhz with manual and probe for $100, but I'm sure I can talk him down from there. The seller has no real idea of the condition of it, but it supposedly powers up a-ok. I plan on using the scope for audio projects like x0xb0x, midibox etc.

[rct]

I plan on using the scope for audio projects like x0xb0x, midibox etc.

For audio you might want to use your soundcard as an oscilloscope. If you are on windows take a look at the Zeitnitz scope software.