advertisement


Finally bought an Oscilloscope

C

Cesare

pfm Member
For whatever reason, i've always fancied getting an oscilloscope to help out with the sort of electronics dabbling I do. My hands on experience would have been in the 80s with 20Mhz bench scopes during school electronics lessons, but more recently i've been working with companies doing a fair bit of EE work (designing electronic instruments) and so have spent time around people probing circuits and getting annoyed when stuff doesn't work and my interest has been rekindled.

The problem was that decent scopes cost more than I wanted to spend, and there were always other things to consider, that realistically, would be more appropriate given my limited knowledge and ability - what exactly would I end up doing with it anyhow?

Being a computer programmer type, the fact that modern scopes can often be hacked has appealed to me - if the machine is really just a computer in a box, then rather than being a fixed device, it would be customised and extended over time.


Anyhow this year i've finally taken the plunge, and i'm now the owner of a Siglent SDS2104X plus (bit of a mouthful that!). It's a 4 channel 100Mhz scope, but includes 16 channels of digital input (if you buy the probes and the software license) and a basic 50Mhz capable signal generator (again, software license controlled). It's very hackable, there's plenty of help getting software codes for it, and I can actually telnet onto it and poke about the system which has given me some ideas of things I could add in the future.

So far, a few weeks into ownership, i'm finding it really excellent. I've managed to debug a couple of old synths that have been messing me about for years (dodgy headphone output on a drum module, tracked down to a dodgy capacitor, and midi out on a keyboard, down to a dodgy NAND gate).

Next up, is dabbling with some FPGA based stuff - first task, build a signal generator. I'm going to have heaps of questions as I go, so please be kind if i'm asking stupid stuff...

So 2022 is going to be a year of electronics (and SystemVerilog) exploration for me - unlock the magic smoke!

PXL_20220129_175700615 by Cesare Ferrari, on Flickr
 
How much for a scope like this? If you don't mind me asking.

I have the prospect of a usable workbench/space soon for some electronics tinkering as I approach retirement - and know I will not get very far without a 'scope. And don't really fancy an ancient old school Tektronix for instance.
 
Yes, half the fun is buying a cheap S/H 'scope and spending time getting it working... :confused:
THEN you can go on to measure stuff! :D
 
JensenHealey said:
How much for a scope like this? If you don't mind me asking.

I have the prospect of a usable workbench/space soon for some electronics tinkering as I approach retirement - and know I will not get very far without a 'scope. And don't really fancy an ancient old school Tektronix for instance.
Click to expand...

The base model was £1200 (including VAT) but I paid more like £1350 and got the digital input adapter. I went for the 100Mhz model with 4 inputs, as the software upgrades support taking it all the way to a 500Mhz scope. This model is their newer platform, and is shared by their much more expensive scopes, so there's been plenty of software updates in the past, and bug fixes and enhancements which made me pretty confident it was still being actively developed as a platform.

The scope is 8 bit, but has a 10 bit mode with a 100Mhz bandwidth limit (it's some sort of hardware resampling algorithm). I was a bit nervous about this as it feels rather limiting, but in reality, since you scale the input amplifiers to the range you really need, and you have all sorts of maths operators for averaging which can be applied, it's not really a limitation that I care about.

If you have a more limited budget, the other option I was considering is the Rigol MSO5000, which more like £900. I think the user interface is less pleasing, but it does in fact have better specs in various areas (8Gs/s, 500,000 captures/sec) but the advice after I dug about was that if you can afford the Siglent, you'll enjoy using it more, but if not, the Rigol is excellent.

I specifically wanted digital inputs, hence these two choices, if you just want analog, I think the cheaper Rigols are where it's at.
 
suzywong said:
Pshaw! Young people of today........can't take hauling Tek scopes around the lab - it strengthened your biceps! :D:D:D


OTOH, Cesere's does look rather good
Click to expand...
long time since was described as young!

Probably last used a scope (on a mainframe computer) in about 1980 - would have been a 'portable' Tek two channel job probably. Signals for some jobs were fast enough that both sig leads and the trigger lead needed to be the same length or you could not get a stable screen. You could spend a good chunk of an afternoon wandering around the site trying to make up a matching set.

My use today would be strictly low frequency -mostly audio
 
JensenHealey said:
My use today would be strictly low frequency -mostly audio
Click to expand...
An electronics lecturer at my college was a specialist in high frequency work. He was quoted (I suspect apocryphally) as saying "if you can't see it, it isn't high frequency"

BugBear
 
Cesare said:
Anyhow this year i've finally taken the plunge, and i'm now the owner of a Siglent SDS2104X plus (bit of a mouthful that!). It's a 4 channel 100Mhz scope, but includes 16 channels of digital input (if you buy the probes and the software license) and a basic 50Mhz capable signal generator (again, software license controlled). It's very hackable, there's plenty of help getting software codes for it, and I can actually telnet onto it and poke about the system which has given me some ideas of things I could add in the future.
Click to expand...
Is it possible to operate it over the network and acquire waveforms etc? I've found that quite useful when the built-in analysis functions have fallen short.

Cesare said:
The base model was £1200 (including VAT) but I paid more like £1350 and got the digital input adapter.
Click to expand...
That's less than half the list price of one of my Tek probes (which I got barely used for a bargain price).
 
mansr said:
Is it possible to operate it over the network and acquire waveforms etc? I've found that quite useful when the built-in analysis functions have fallen short.

That's less than half the list price of one of my Tek probes (which I got barely used for a bargain price).
Click to expand...

Yes indeed. It has an ethernet port, and you can connect to it via VNC and get the complete screen, and capture and store output data onto the front USB port (and I think a mounted network share, although i've not tried that).

In addition, it's supported by glscopeclient, so there's an open source software interface which connects to the scope via ethernet and pulls the data across. This also means that you can take advantage of any software decoders that have been written for it, and obviously write your own analysis tools.

https://hackaday.com/2019/05/30/glscopeclient-a-permissively-licensed-remote-oscilloscope-utility/

I've not tried it, i'm short of a linux machine with openGL support at the moment, but that was part of the appeal to future proof the hardware.

As for expensive probes, that is certainly a limitation i've got with my setup. The probes are good for 200Mhz, so not exactly top draw performers. I have read that they typically outperform this rather well, and are good for 350Mhz but maybe down 1 or 2 db. The scope can sense 1x/10x probe switching, but the probes don't support this... It does have a 50ohm input option.

Given that the same hardware is sold at £3k+ prices with 500Mhz bandwidth, I think the unit itself outperforms the probes I have, but i'll have to get much further into this before I feel it'll hold me back...
 
cj66 said:
Always fancied one but wouldn't know how to use it! :oops::p:)
Click to expand...

Yeah, I understand, and that's why I got one. I've always fancied one, and want to know how to use it. Can't learn to ride a bike without a bike, but that doesn't stop you buying one and working it out.
 
Very fair enough, point well made and maybe I should get off my proverbial and do the same.
 
I recently bought a Rigol ds1032e, I got fed up of fixing my Tektronix TDS320, basic two channel but more than adequate for what I want at home, the spi and i2c decoder is nice.
 
I'm a sucker for old CRT oscilloscopes. I've got a Tektronix 2235 and a lovely old 465B 'boat anchor'.

The 465B is just so darn lovely but TBH the 2235 works just as well and weighs about half as much!

Still, the 465B is comparatively featherweight compared to my ancient Iwatsu spectrum analyser which is a hernia waiting to happen.

20210327_203412 by Michael Pickwell, on Flickr

557 eye pattern by Michael Pickwell, on Flickr

20210323_111400 by Michael Pickwell, on Flickr
 
Eye patterns look so very different on a digital scope. I think the first generation of them struggled with this sort of display, but the Siglent has some very nice options that help and in fact make it much more understandable to me. I'll stick up an example when i'm back home (currently away)
 
You must log in or register to reply here.


advertisement


Back
Top