Oscilliscope advice

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Stew
Posts: 495
Joined: 02 Mar 2018, 10:21
Location: Staindrop, Darlington.

Oscilliscope advice

Post by Stew »

Hi all.

Can anyone point me towards a cheap scope that will allow me to play with 27 and 35 mhz sets? Doesn't have to be fancy.

Cheers

Stew.
bluejets
Posts: 316
Joined: 19 Jun 2019, 04:09

Re: Oscilliscope advice

Post by bluejets »

DSO150...many online suppliers....AUD$40-$50
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Mike_K
Posts: 669
Joined: 16 Feb 2018, 06:35
Location: Hertfordshire

Re: Oscilliscope advice

Post by Mike_K »

For the last 15 years I've used Pico Technologies scopes, I've got 3 of them now and I highly recommend them. They connect to a PC via USB and have software for digital storage scope, frequency analyser, logic analyser and logic decoder (for RS232, SPI, I2C etc), they don't have their own display. The reason for having 3 of them is to give multiple channels, the software supports multiple scopes to make a single multi-channel scope. The customer service is fantastic, my 15 year old model is still supported and when it went wrong they repaired it free of charge (years out of warranty). The only downsides are the cost and you do need a laptop, but my bench always has a laptop for programming Arduino.

https://www.picotech.com/products/oscilloscope

I personally wouldn't recommend the DSO150, while they're very cheap, their bandwidth is only150 or 200KHz (depending on the model), which isn't really enough for R/C use, for example, if using it for looking at a ppm signal it can only resolve to +/-5uS and forget using it for the rf stages. I'd go for a scope with a minimum of 100MHz bandwidth if you budget runs to it, think of it as an investment as it will pay you back over time.
Stew
Posts: 495
Joined: 02 Mar 2018, 10:21
Location: Staindrop, Darlington.

Re: Oscilliscope advice

Post by Stew »

Thanks for the advice guys, Hmm, it's not a straightforward one... I shall do some reading..
Martin
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Joined: 16 Feb 2018, 14:11
Location: Warwickshire

Re: Oscilliscope advice

Post by Martin »

I have one of the relatively cheap, but 'full sized' digital 2 channel scopes from China. Mine is a Atten, but I don't know if that brand is still around. It can connect to a PC, but it also has its own built-in display, and I always use that: I don't like the hassle of connecting to a PC, and finding, possibly updating, the 'scope' program - and often the PC(s) on my desk will be connected to the gadget I want to scope - running serial monitors or programming IDEs.

You can get reasonable scopes like mine, some with built-in signal generators too, for less than £200. In my opinion, it's worth investing in an oscilloscope that's a little more capable than you think you need - you won't regret it.
Ginger
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Joined: 27 Mar 2018, 17:29

Re: Oscilliscope advice

Post by Ginger »

viewtopic.php?t=829
Phil's Siglent
Stew
Posts: 495
Joined: 02 Mar 2018, 10:21
Location: Staindrop, Darlington.

Re: Oscilliscope advice

Post by Stew »

Hi Ginger.

Thanks for that, I've been looking for that thread!
I'm in the 'catch 22' situation of not knowing enough to get maximum use out of such a device, but unless I get one, I'll not be able to learn!

Stew.
Dave
Posts: 7
Joined: 14 Feb 2022, 03:24

Re: Oscilliscope advice

Post by Dave »

If you search Youtube for' DSO138 Oscilloscope' you might be tempted.

It should show CPPM pulse trains OK and an RF diode probe on the input will show 27/35Mhz RF levels and any AM modulation.
Pchristy
Posts: 413
Joined: 16 Feb 2018, 13:57
Location: South Devon, UK

Re: Oscilliscope advice

Post by Pchristy »

Don't forget the second hand market! Oscilloscopes are generally pretty robust and built for industrial use! While a faulty one can be difficult to fix (unless you have the service manual and another 'scope!), they generally either work or don't work.

My first decent 'scope was from a second-hand electrical junk shop near Heathrow. It was an enormous, all valve device, which doubled up as a heater for my shed! About 40 years ago, I invested in a Hameg 203, which still sits on my bench working fine.

Whilst a basic 20 MHz scope won't allow you to measure 27 or 35 Mhz, it should be able to tell you if its there or not. It should display the RF envelope, even if it displays a smaller amplitude than it actually is. Certainly good enough for a go/no-go test.

Obviously second hand stuff carries the usual "buyer beware" warning, but there are some bargains out there. Private sellers like this: https://www.gumtree.com/p/medical-labor ... 1424694149

Commercial resellers will be more expensive, but usually offer some kind of guarantee: http://www.stewart-of-reading.co.uk/Oscilloscopes.htm My spectrum analyzer originally came from these people. Their current stock list shows a couple of low-end scopes that shouldn't be too expensive: LEADER LBO523 Dual Trace 35MHZ
GOULD OS300 Dual Trace 20MHZ

You don't need more than dual trace for entry level, nor will you need a storage scope. You will need a 10x probe or two: https://www.amazon.co.uk/s?k=10x+oscill ... d2ief58u_e

Also check local electronics shops (if you can find any!) and local ads on ebay, gumtree etc. If you can find a local one, you can ask to see it working! ;)

Best of luck!

--
Pete
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Mike_K
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Joined: 16 Feb 2018, 06:35
Location: Hertfordshire

Re: Oscilliscope advice

Post by Mike_K »

Stew,

Pete's post got me thinking about old oscilloscopes and I realised I still have my "previous" scope sitting on a shelf and unused for around 10 years and probably never will be used by me again. Last night I got it off the shelf, cleared a layer of dust off, powered it up and it still works perfectly. You are quite welcome to it, but I don't know if it would survive the post, it weighs an absolute "ton" and it would be a shame to break it in the post. Are you going to Ponty this May? If you are and could be patient until then, I could bring it along. It's an old Beckman dual-channel 20MHz storage scope, it was second hand when I bought it 20+ years ago, so there's no warranty, but in my opinion, it's infinitely better than a DSO138 type oscilloscope.

Now I don't want to criticise the DSO138 type oscilloscope, but when I searched on YouTube, the second suggestion was "Why you shouldn't buy one"!



The YouTube clip clearly demonstrates their limitations, but as they're only around £30 including shipping and tax I've ordered one from AliExpress to see how useful for R/C electronics work it could be, if it's absolutely useless it can be a "booby prize" for Ponty, I know Shaun will be looking for a few prizes...

Mike
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