Author Topic: Oscilloscopes  (Read 337 times)

Oscilloscopes
« on: July 21, 2020, 05:05:44 pm »
So I have a sudden yen to start messing around with electronics. I sort of know what most of the basic components do due to A level physics and the first year of an Electronics/Electrical engineering degree (that had far too much electrical engineering rather than electronics hence why I quit) several decades ago and have some spare cash to blow on collecting the required kit.

I have picked up a couple of nice bench power supplies second hand (that was easy I understand them and just looked for good makes) and already have an OK soldering iron but oscilloscopes .... Last time I played with one of those they looked like the sonar set from a WWII submarine. Taking a look around things have moved on, a lot.

I will be fiddling with 70s and 80s HiFi and also general logic stuff and computers. I can seem to find a clear guide on what specs are needed for what application.
A basic 100Mhz 4 channel hobbyist scope runs about £500 (eg a Siglent SDS1104X-E ) and the next grade up is about £1200 (eg a Siglent SDS2104X Plus).

Is 100Mhz enough ?
What other features would I miss out on by not spending more?

What I don't want to do is blow £500 on something that 6 months down the line is going to be so restrictive that I end up buying a second more expensive one. If that's the case I might as well swallow the pain and go straight for a better one now. There again if I am never likely to use the features of a better one no point wasting money on one and I should get the cheaper one and be happy.
I think you'll find it's a bit more complicated than that.

Re: Oscilloscopes
« Reply #1 on: July 21, 2020, 05:45:00 pm »
A basic four channel 100 MHz is likely to be missing lots of fancy add-on features that you don't know you need - things like signal decoding (seeing what's inside a serial data stream), fancy triggers, huge memory buffers, maths functions, etc.

OTOH, it's going to be far *more* than you need for most hobbyist dicking about with analog electronics and small scale logic.

There are some interesting tablet scopes and multimeters that can show waveforms that target this market, and cheap scope interfaces that plug into PCs. So one approach could be to spend £100-200 on one of these and buy a proper scope later if you think you need one. But then you might feel left out by not having a "proper" scope until then, so you can't win.

Re: Oscilloscopes
« Reply #2 on: July 21, 2020, 07:27:39 pm »
Pico technology have a range of usb pc scopes from budget to spendy.
Software is good. British company

Re: Oscilloscopes
« Reply #3 on: July 21, 2020, 07:37:24 pm »
Pico technology have a range of usb pc scopes from budget to spendy.
Software is good. British company
This. Even the basic models work well and have signal decoding, complex triggering etc. You pay for bandwidth, so budget models are 10 MHz, I think, but that is plenty for most things.
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Karla

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Re: Oscilloscopes
« Reply #4 on: July 21, 2020, 07:40:46 pm »
100MHz?  If you only want to look at signals up to 50 MHz, fine.  If you want to look at anything faster, not fine.

Kim

  • Timelord
Re: Oscilloscopes
« Reply #5 on: July 21, 2020, 07:51:04 pm »
Rigol DS1054Z is surely the hobbyist default these days.  It's hard to beat for the price (especially if you factor in the availability of key-generators to unlock the premium features on the merkier parts of the internet).

I expect analogue scopes are cheap as chips on eBay.  (I got a decent 40MHz one with basic digital storage and measurement functions for £100 back when I was a PSO.)  They're not a terrible idea for learners, but they're huge and digital scopes are immeasurably better for most practical purposes.

I wouldn't want a USB scope for the simple reason that when I'm mucking about with electronics, the computer is probably already busy with datasheets, source code or serial terminals - a hardware scope means less window juggling (and digital scopes can do data capture for when you want it anyway).  Their main advantage is price, portability and ease of automation.  Disclaimer: It's a long time since I used one, and it was fairly rubbish.

100MHz is almost certainly enough for audio and basic digital stuff.  I rarely probe anything above a couple of Mhz (and usually just to check a clock is ticking) - most of what I deal with is power supplies and serial busses.  YMMV if you're an RF jibbler.  To me signal decoding's the killer feature of the higher-end stuff, but if you need the bandwidth, you need the bandwidth.
Careful, Kim. Your sarcasm's showing...

Re: Oscilloscopes
« Reply #6 on: July 21, 2020, 08:01:59 pm »
+1 for Picoscope. If you want to go really cheap there is always Hantek, but I've had a few problems with them.

I'm going to have to disagree with Kim on this, as nowadays I don't see a lot of reason to use a standalone scope, and most of the time I want to capture data anyway. For me 100MHz would be more than enough, but it really depends on what you plan to look at. I would rarely (if ever) have to deal with a signal above 20MHz.

Re: Oscilloscopes
« Reply #7 on: July 21, 2020, 08:13:54 pm »
Rigol DS1054Z is surely the hobbyist default these days.  It's hard to beat for the price (especially if you factor in the availability of key-generators to unlock the premium features on the merkier parts of the internet).

The Siglant SDS1104X-E seems to have taken over. Much newer, same ability to be hacked to unlock all features including 200Mhz.

https://www.siglent.eu/product/1139249/siglent-sds1104x-e-100mhz-four-channel-oscilloscope

Web based GUI as well so you can control it from a PC as well.

Their next range up can be unlocked all the way to 350Mhz but the base 100Mhz model is about £600 more expensive. Nice big 10.1 inch touch display though. AGain easy to hack to enable all features and speeds.

https://www.siglent.eu/product/1182111/siglent-sds2104x-plus-4ch-100mhz-2gsa-s-oscilloscope
I think you'll find it's a bit more complicated than that.

Kim

  • Timelord
Re: Oscilloscopes
« Reply #8 on: July 21, 2020, 09:04:32 pm »
I don't see a lot of reason to use a standalone scope

Knobs.  Though, tbh, if you want really good knobs, you've got to go analogue.
Careful, Kim. Your sarcasm's showing...

BrianI

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Re: Oscilloscopes
« Reply #9 on: July 21, 2020, 09:18:59 pm »
An old analogue scope, so you can play oscilloscope music!

 https://youtu.be/XziuEdpVUe0 :thumbsup:

Vernon

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Re: Oscilloscopes
« Reply #10 on: July 21, 2020, 10:34:16 pm »
It might be worth looking at salae usb scopes. I got a logic 8 for a work colleague as a leaving present a few years ago (I was team leader at the time, and they were considerably cheaper then), and I was impressed by the software capabilities. I understand they do discounts for enthusiasts and students. I believe you can get cheap knock-off clones for them as well, but I wouldn't condone that.

Re: Oscilloscopes
« Reply #11 on: July 22, 2020, 04:07:06 pm »
Thanks all. Might have to mull this one over for a while. This is for a winter hobby anyway.

As an aside if anyone is looking for a bench digital multimeter this eBayer has new old stock of TTi 1705GP bench multimeters at less than 50% of the cost when they were the current range. I just bought one.

https://www.ebay.co.uk/itm/DIGITAL-MULTIMETER-TTI-1705GP/174258712547?hash=item2892a0efe3:g:SRAAAOSwnhFeoDE-

They can work off batteries as well as mains. 
I think you'll find it's a bit more complicated than that.