Best analog scope for hobby electronics? - Page 1
Forum section: electronics / beginners

author: JohnBee
author_rank: Contributor
timestamp: March 25, 2017, 06:40:12 am
content: So glad to finally get my registration approved. I signed-up several weeks ago but the registration was never sent out it appears.That said, I purchased an old analog Phillips scope on the cheap from eBay nearly a year ago, but it conked out only hours after turning it on - screen gave out it seemsAnd so I'd still like to get an analog scope one for the sake of experimentation, and so I wanted to ask if anyone had any recommendations on what I should aim for?In addition to this, and if this means anything, I'd really like to get one with a frequency counter built-in, rather than to have to calculate things using the timebase.The circuits I'm playing with are ranging from 10Hz to 25Mhz

author: tpowell1830
author_rank: Frequent Contributor
timestamp: March 25, 2017, 06:53:31 am
content: Quote from: JohnBee on March 25, 2017, 06:40:12 amHi JohnBee, welcome to the forum.So, you don't want a 20 MHz, or an analog scope. The Tektronix TDS210 digital scope will do it if you could find a used one.Edit: Keysight is giving away scopes in March at scopemonth.com

author: BravoV
author_rank: Super Contributor
timestamp: March 25, 2017, 06:55:18 am
content: Quote from: JohnBee on March 25, 2017, 06:40:12 amYou mentioned analog scope, and we know its almost impossible to find new ones (read : with warranty).What if the another new bought "used" analog scope "conked" out ... again ?My 2 cents, get a new DSO and read my sig below.

author: boffin
author_rank: Unknown
timestamp: March 25, 2017, 07:01:58 am
content: Quote from: JohnBee on March 25, 2017, 06:40:12 amYou could have a shot at fixing it. I purchased a (broken) Philips 3216, and in the end it was a fairly simple fix in the power supply (a bad trimmer)

author: JohnBee
author_rank: Contributor
timestamp: March 25, 2017, 07:26:30 am
content: Quote from: boffin on March 25, 2017, 07:01:58 amMine is a PM-3212The screen seems to be dimming on it. Tried adjusting the brightness contrast settings but it doesn't seem to help.Any ideas or suggestions as to what I could look toward in terms of troubleshooting the cause?

author: JohnBee
author_rank: Contributor
timestamp: March 25, 2017, 07:30:07 am
content: Quote from: tpowell1830 on March 25, 2017, 06:53:31 amThanks for the input.On the scope type, I was kind of leaning toward Dave's recommendations in the "setting up an electronics lab" video. And so I thought I'd start off with an Analog scope.And thanks for the Keysight tip, signed-up with fingers crossed :p

author: kripton2035
author_rank: Super Contributor
timestamp: March 25, 2017, 07:39:10 am
content: if you have $400, invest in a rigol ds1054z, there are a lot of topics about it on the forum.you will be able to do all your hobby electronics and more.if you don't have $400, then begin to save to get them...orbuy a used analog scope in good conditions, but don't spend more than $100-$150 in it(remember you have to save $$$ for the 1054z !)

author: tpowell1830
author_rank: Frequent Contributor
timestamp: March 25, 2017, 07:46:01 am
content: Quote from: JohnBee on March 25, 2017, 07:30:07 amWell, you did say that you were wanting to measure 25 MHz and have a frequency counter. The TDS 210 is a very simple digital scope and you can quickly and easily measure frequency and time. A used one is fairly inexpensive, but the Keysight 1000X is just a few hundred dollars more than a used TDS 210. If money is the issue, and your heart is set on analog, then go with a BK Precision Model 2125A that will measure 25 MHz. Should be able to get a used one for $200 or less. But, it will not measure frequency for you.

author: j57H8I4
author_rank: Contributor
timestamp: March 25, 2017, 09:55:45 am
content: Do not buy an old analog oscilloscope without its service manual, otherwise you will likely need to take it to an assistance service, that would cost you a lot compared to the oscilloscope value.Check that the oscilloscope does not have any sign of rust, because that could indicate that it was kept in a moist environment so that it could have contacts oxidation issues.

author: Martin.M
author_rank: Frequent Contributor
timestamp: March 25, 2017, 10:10:07 am
content: the question was for an analog scope.I think a Tek 453 is the right solution, mostly to get for roundabout 50 bucks.It is a 50mc 2 channels analog scope, one of the best in the old time.The Type 454 ist the same but 150mc bandwith.For homebrew projects this old instruments do a perfect job, much better then the most scopes from philips.seewww.wellenkino.de/453this scopes are made for a long life, all transistors are in sockets, there are no IC inside.So the service is easy, no swap of complete boards. The quality inside is amazing, 453 was expensive and looks expensive. A lot of gold plated parts.Frequency counter is to use extern.Analog scope with frequency counter, is imho more expensive then a low cost DSO. This can be any Tek of the 7k series equipped with a 7D15 counter plugin.greetingsMartin

author: tggzzz
author_rank: Super Contributor
timestamp: March 25, 2017, 10:31:15 am
content: Quote from: JohnBee on March 25, 2017, 06:40:12 amFrequency counters measure waveforms with constant frequency and well-defined transitions. Scopes aren't the best thing for that. For that it might be best to get a ... frequency counter! They will give you a more better measurement; with analogue scopes you are looking at a 1% tolerance at best.If your waveforms are not a constant frequency (e.g. a digital signal) or don't have a well-defined transition (e.g. noise, harmonics), then it is usual to select and measure a time interval and then calculate the inverse.There are analogue scopes which can give a readout of time and frequency. I'd look at secondhand Tektronix scopes with part numbers >2000Make sure it is fully working before purchase. Look at the TekWikihttp://w140.com/tekwiki/wiki/Main_Pagefor basic and detailed info on Tek scopes etc.I'm only familiar with the 24x5 scopes. The 24x5 and 24x5A have cursors you place manually and the readout shows where they are. The 24x5B has an auto measurement mode where it positions the cursors for you.

author: joseph nicholas
author_rank: Frequent Contributor
timestamp: March 25, 2017, 10:33:38 am
content: I just bought a non working Tek 453 for about $35usd including shipping. It will be delivered on Monday. It is said to have a fuse blowing problem, but if you put in a higher value fuse, it will show a trace. Getting a pdf manuel on line was very easy. I will use it in combination with my JYE DSO 138 for experiments. When fixed i plan to sell it on the local market, as a vintage old school scope for about $100.

author: tggzzz
author_rank: Super Contributor
timestamp: March 25, 2017, 10:49:52 am
content: Quote from: JohnBee on March 25, 2017, 07:26:30 amThe first thing you should do is measure the power supply rails to see they are accurate and without ripple. Electrolytic capacitors are usually the culprit there. (Stay away from the >2kV circuit unless you know what you are doing)Presuming that the trace is bright when you turn it on and then dims, but the size position and focus of the trace are unchanged, then I would suspect there is a problem with the Z-axis waveform. That comes in two variants: the "LT" version (range 0-150V) and exactly the same waveform "shifted up" to be between the CRT's grid and cathode at 2-3kV. The "DC restorer" circuit does that, and the HV diodes and capacitors in it often becomesubtlyfaulty with age. "Subtly" means that a simple diode tester won't spot the problem.Contrary to popular belief, it is not necessary to have scope to debug such problems; I've done it with just a multimeter and a lot of thought and understanding, and care. The easy test would be to put a multimeter across the LT Z-axis waveform and measure the mean voltage (somewhere 50-120V, depending on timebase and other front panel controls). If that remains constant while the trace dims, then the problem is likely to be in the DC restorer.When dealing with DC restorer problems, it is usual to simply replace all those diodes and capacitors rather than to diagnose which is more faulty. Make sure you get diodes with appropriate voltage, current and turnoff times. Capacitors need to have appropriate voltage, but the capacitance value does not have to be exactly the same.Be aware that voltages will be stored on those capacitors for a long time, and make sure you understand the practical consequences of "soakage" or "dielectric absorbtion".

author: mzacharias
author_rank: Frequent Contributor
timestamp: March 25, 2017, 11:14:08 am
content: Your older, Japanese made B&K models, made by Kenwood (Trio), are almost bullet-proof and never seem to need anything more than cleaning controls and switches.There was a brief time during which a few B&K's were made in Korea by LG. Plain looking but good performers.The Taiwanese models made after that are crap.

author: Shock
author_rank: Super Contributor
timestamp: March 25, 2017, 03:38:45 pm
content: CRT scope is not the best first time repair unless it's obvious, you have to avoid the high voltage circuits, which is 1-10kV btw and deadly. Similar model linked below, I recommend watching this whole video series regardless.As you can see there is +180V and -180V on the top board which can catch out any carelessness really quick. If you have absolutely no experience best to work up to this over time. Imagine if you didn't read the PCB or service manual and thought it was 40V, grab that seemingly low voltage connector unplugged and hello, 360V.But one thing you could do is give the controls a good working over when it's off and see if it was a dirty contact.https://www.eevblog.com/forum/repair/philips-pm3214-oscilloscope-repair/

author: Shock
author_rank: Super Contributor
timestamp: March 25, 2017, 03:52:20 pm
content: I'd also recommend the Rigol DS1054Z digital but make sure you're actually doing something with it before you just go out and buy another scope.Problem with older analog oscilloscopes is as you discovered unless they have been serviced they need a little attention and there is no guarantee that you are going avoid breakdowns on a 30 year old scope. If you do decide on analog there is plenty of threads here on what to get. Or find someone nearby to help repair yours if you lack fundamentals.

author: kripton2035
author_rank: Super Contributor
timestamp: March 25, 2017, 05:26:02 pm
content: today's "hobby electronics" almost always involve doing arduino stuff, so dealing with i2c,spi, uart.then an analog scope makes no sense.if you're only learning with resistors, capacitors and transistors, then an analog scope could be ok, but will soon show it's limits.if you're on a tight budget, then see my previous post !

author: gildasd
author_rank: Frequent Contributor
timestamp: March 25, 2017, 06:01:49 pm
content: Any analogue scope you can get for free?

author: alm
author_rank: Super Contributor
timestamp: March 25, 2017, 08:09:05 pm
content: Quote from: kripton2035 on March 25, 2017, 05:26:02 pmAn analog scope works fine for checking signal integrity with a steady test pattern (e.g. sending UUUU over RS-232) or checking power supply rails for noise. And a cheap logic analyzer (for example those cheap $10 USB things with Pulseview) can handle most other tasks. Sure, there are times when you would like mixed-signal capabilities, and single shot triggering can save time modifying software to output test patterns, but <$100 for a 20-100 MHz analog scope + $10 for a USB logic analyzer is a lot cheaper than the cheapest usable DSO with decent memory and sample rate.

author: tggzzz
author_rank: Super Contributor
timestamp: March 25, 2017, 08:18:52 pm
content: Quote from: alm on March 25, 2017, 08:09:05 pmAnalogue scopes have always been able to assure signal integrityextremelywell for randomly changing digital signals. Look at any manufacturer's application notes about "eye diagrams".QuoteYes. I wish people would understand that it is sufficient (and often better) to measure analogue signals to validate signal integrity, and then to flip to the digital domain to see what the digits are.I'll note that the Digilent Analog Discovery has a 100MS/s 16 channel pattern generator and logic analyser as well as its scope, AWG and post-processing tools.

author: rstofer
author_rank: Super Contributor
timestamp: March 25, 2017, 08:20:33 pm
content: Quote from: JohnBee on March 25, 2017, 06:40:12 amThe important consideration is whether they are analog or digital signals. A 25 MHz sine wave may display pretty well on a scope with a BW of 25 MHz but a 25 MHz square wave will look just like a sine wave.For the square wave, you need to get at least the 5th harmonic and, more likely, the 7th and 9th. To realistically display a 25 MHz square wave you need a scope with a BW of at least 200 MHz and that only gets you up to the 7th harmonic.The highly regarded DS1054Z, unlocked to 100 MHz works pretty well up to 10 MHz for a square wave.About 12 years ago, I picked up a Tek 485 for around $200. This is a 350 MHz scope! These are all over eBay and the prices are all over the map.When you're thinking about a scope, the first question should be bandwidth.

author: tggzzz
author_rank: Super Contributor
timestamp: March 25, 2017, 09:19:04 pm
content: Quote from: rstofer on March 25, 2017, 08:20:33 pmPrecisely, and my 485 is my favourite scope, despite having later scopes.The killer feature of digital scopes, however, is not protocol decided but it is the ability to capture the few truly single shot events you are likely to encounter. Power supply turn on/off transients are the canonical example. By comparison, analogue storage scopes are a pain in the posterior. And yes, I did use them before DSOs were practical, and I do have a working Tek 464

author: rstofer
author_rank: Super Contributor
timestamp: March 25, 2017, 10:35:49 pm
content: Quote from: tggzzz on March 25, 2017, 09:19:04 pmAbsolutely! That single shot capture is a terrific feature; I use it all the time.The DS1054Z is my first DSO and I have a lot to learn about its capabilities.

author: boffin
author_rank: Unknown
timestamp: March 25, 2017, 10:43:11 pm
content: Quote from: JohnBee on March 25, 2017, 07:26:30 am1st thing to do is try and find an appropriate schematic. It doesn't have to be the 3212, but the same series.OK, I just had a look, and I actually have a 3212 PDF manual. Send me a PM with your email address and I'll forward it along..As that crazy aussie says, "Thou shalt check voltages", so starting at the PSU is the best place. Now these things are known to blow their transformer, and that's essentially unrepairable; but you've got it and there's no need to toss it just yet - it doesn't matter if you make it more broken.HOWEVER: there are some pretty nasty voltages inside, so please be careful and do so at your own risk.

author: JohnBee
author_rank: Contributor
timestamp: March 25, 2017, 10:53:32 pm
content: Quote from: boffin on March 25, 2017, 10:43:11 pmSounds great!And thanks so much for following through.I'm thinking the best scenario in this case, would be to fix the Phillips rather than to buy into another scope. And so, here's to hoping I can pull it off

author: David Hess
author_rank: Super Contributor
timestamp: March 26, 2017, 09:40:18 pm
content: Analog oscilloscopes that I would consider in rough order of age:453A 60 MHz Dual Timebase454A 150 MHz Dual Timebase455 50 MHz Dual Timebase Ruggedized465M 100 MHz Dual Timebase Ruggedized465B 100 MHz Dual Timebase (1)2213A 60 MHz Single Timebase2215A 60 MHz Dual Timebase2235 100 MHz Dual Timebase2235A 100 MHz Dual Timebase2225 50 MHz Single Timebase 500uV/div2335 100 MHz Dual Timebase Ruggedized2336 100 MHz Dual Delta Delay Timebase Ruggedized2337 100 MHz Dual Delta Delay Timebase Ruggedized2245 100 MHz Dual Timebase 4 Channels2245A 100 MHz Dual Timebase 4 Channels2246 100 MHz Dual Delta Delay Timebase 4 Channels2246A 100 MHz Dual Delta Delay Timebase 4 ChannelsThese analog oscilloscopes have fantastic gated universal timer/counters:2236 100 MHz Dual Delta Delay Timebase2236A 100 MHz Dual Delta Delay Timebase2247A 100 MHz Dual Delta Delay Timebase 4 Channels2252 100 MHz Dual Delta Delay Timebase 4 ChannelsThese analog oscilloscopes have digital storage capability allowing cursor frequency measurements:2221 100 MHz Single Timebase 100ns Glitch Detect Based on 22302221A 100 MHz Single Timebase 10ns Glitch Detect Based on 22322224 60 MHz Dual Timebase 10ns Glitch Detect Based on 22322230 100 MHz Dual Timebase 100ns Glitch Detect Based on 22352232 100 MHz Dual Timebase 10ns Glitch Detect Based on 2235 My Favorite Old DSO2211 50 MHz Single Timebase Based on 2225(1) A 465B with the DM44 attachment has delta delay based frequency measurement capability.

author: rstofer
author_rank: Super Contributor
timestamp: March 26, 2017, 10:28:29 pm
content: There's a nice, clean and calibrated 2232 on eBay right nowhttp://www.ebay.com/itm/Tektronix-2232-100MHz-Digital-Storage-Oscilloscope-Cald-tested-probes-/272597811638

author: David Hess
author_rank: Super Contributor
timestamp: March 27, 2017, 12:10:08 am
content: Quote from: rstofer on March 26, 2017, 10:28:29 pmI can vouch for shockcore on Ebay having bought from and interacted with him before but $300 may be too much for an old oscilloscope for hobby use.The 2232 does not have automatic measurements but instead uses an excellent set of cursors in digital storage mode to make voltage, time, and frequency measurements; just do not expect the resolution and accuracy of a dedicated frequency counter.