Author Topic: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay  (Read 12209 times)

0 Members and 1 Guest are viewing this topic.

Offline EEVblog

  • Administrator
  • *****
  • Posts: 29650
  • Country: au
    • EEVblog
EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« on: September 14, 2017, 11:20:56 pm »
Another look at finding a $50 analog oscilloscope on ebay.
A follow-up from a video from 4 years ago.
 
The following users thanked this post: djos, Electro Detective

Offline dardosordi

  • Regular Contributor
  • *
  • Posts: 81
  • Country: ar
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #1 on: September 15, 2017, 12:11:10 am »
Dave, last time I listened to your scope video I ended up like this:  :scared:

Scored 3 Tek 2245A for ~160 USD, ended up selling 2 and that paid for most of it.
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 29650
  • Country: au
    • EEVblog
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #2 on: September 15, 2017, 01:01:36 am »
Dave, last time I listened to your scope video I ended up like this:  :scared:
Scored 3 Tek 2245A for ~160 USD, ended up selling 2 and that paid for most of it.

Great work!
Those kind of flips are certainly possible, I've done it myself several times before.
Easier in countries like Australia were you can buy form the US cheap and resell here for much higher price (including covering the shipping).
 

Offline n3vti

  • Contributor
  • Posts: 30
  • Country: us
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #3 on: September 15, 2017, 01:10:23 am »
I managed to score a Tektronix T922 (20 MHz) and a T932 (35 MHz) a few years ago. I paid about $102 for everything. I was originally getting the 922, but the seller found the 932 and offered to throw it in for free. Sadly, when it came in, the casing on the 922 was destroyed, and the 932 barely worked, and was missing a channel input. My original intention was to combine the two into one working unit, but I never got around to it.  :( Hopefully, i can get it working again and have it as a backup to my Tek 2446  :)
 

Offline cdev

  • Super Contributor
  • ***
  • Posts: 5082
  • Country: 00
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #4 on: September 15, 2017, 01:39:34 am »
I got a 2211 in mint condition that seems to still be 'in calibration' in terms of accuracy for $75. Its a very useful, usable scope.
"What the large print giveth, the small print taketh away."
 

Offline nixfu

  • Supporter
  • ****
  • Posts: 343
  • Country: us
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #5 on: September 15, 2017, 03:50:02 am »
Wish the price of 465s would come down.  I would like to have one.  But,  I think 465s are starting to be more of a collectors item now and the prices are actually going up.
« Last Edit: September 15, 2017, 03:56:39 am by nixfu »
 

Offline Barny

  • Frequent Contributor
  • **
  • Posts: 283
  • Country: at
  • I'm from Austria, not Australia ;)
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #6 on: September 15, 2017, 07:21:54 am »
I had the luck to get a 20 MHz two channel oscilloscope for 50 euro cent some time ago.
The guy selling it to me was taking it to the scrap yard in useable condition.
(I paid insane 12 Euro for the probes at Amazon.)
The only negative I'm able to say about this oscilloscope is the extreme fiddly trigger because there is no indication of the trigger level.

Sadly I dont knew the exact type anymore, because I gave it to my nephew short after I bought it.
I think it was a Goldstar or some other brand with Gold in its name.
(I have a DS 5152MA and had no space for a second one.)


[Edit]
I think I'm a little weirdo because I normally don't buy used tools and save a little longer to buy new ones.
It's because you never knew how the previous owner treated them.
[/Edit]
« Last Edit: September 15, 2017, 09:16:49 am by Barny »
 

Offline bjcuizon

  • Frequent Contributor
  • **
  • Posts: 284
  • Country: nz
  • RF and Analog Electronics Enthusiast
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #7 on: September 15, 2017, 09:43:41 am »
The bay will be flooded with >$100 scopes in no time. :D :D ...the eevblog effect. :-BROKE
Don't mess with an Electronics Engineer, it Megahertz!
 

Offline kosine

  • Regular Contributor
  • *
  • Posts: 127
  • Country: gb
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #8 on: September 15, 2017, 09:52:50 am »
Don't rely on ebay - too many people looking for bargains. I got a 50MHz Hitachi V-522 'scope in great condition from Bidspotter in the UK. Paid just £20 for it. (Postage and buyer's premium added another £30, but still a good deal.)

It came from a liquidated caravan company, so I was the only bidder. Every town has auctioneers handling company liquidations, so they're a good place to keep an eye on.
 

Offline Electro Detective

  • Super Contributor
  • ***
  • Posts: 2093
  • Country: au
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #9 on: September 15, 2017, 11:00:14 pm »
The darker reality is that a fully functional analogue oscilloscope isn't going to happen EASILY for $50 in Australia, or anywhere else unless you've got a bottled Genie granting wishes  :clap:

Seriously consider spending upwards of $120 to $250 for a fully functional analogue oscilloscope owned by someone moving on or upgrading,
that's looked after it, and not scared to demo it working properly or let you have a tweak.

Half trashed or intemittent oscilloscopes are more trouble than they're worth for a newb, hobbyist, repair tech or a EE that just wants to get on with it

Do the math: how much is a knackered $50 cro going to cost in time, and parts if you can get them|O
AND access them on the board without banging up other parts, avoiding sensitive 'unobtanium' components, 2000 volt zaps and much higher voltages.  :o

If the calibration is miles off, and troubleshooting and probing waveforms via a service manual on a faulty device or any DUT, you are SOL in any direction.  :-[


$50 oscilloscopes are great for repair people that can fix and calibrate them, keep a couple (or MORE! lol) for themselves,

then resell at $120 to $250 to users that need to get work done, not crossing their fingers their test gear is working


It saves these great pieces of kit from the landfills, puts a few dollars in the sellers and repairers pockets,

and buyers get a classic WORKING oscilloscope for the price of a decent multimeter (or 2 tanks of petrol) 

especially good news if cheap DSLows don't quite do it for them,

which may one day come in handy for practicing topedoes and dropkicks in the back yard


Do yourself a favour and make sure your first analogue oscilloscope is a WORKING one and avoid disappointment. 
Mine was a used  -everything working-  Trio-Kenwood 15mhz dual channel, still kicking goals 20+ years later   :-+

« Last Edit: September 15, 2017, 11:09:31 pm by Electro Detective »
 

Offline Towger

  • Super Contributor
  • ***
  • Posts: 1551
  • Country: ie
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #10 on: September 15, 2017, 11:14:48 pm »
Depends.  A few years ago I got a "fully working" Tec 2235 off eBay locally for €50. Probably spend another 50 on replacing a couple of control pots and knobs, and new probes.  It sat on the shelf for a couple of years, until I gave it away for the cost of postage to a young lad on the fourm looking for a free/cheap scope.

So I got a scope for €50 (a hard, but not impossible task in Ireland) got entertainment fixing it up and passed to on to a good cause.
 

Offline bjcuizon

  • Frequent Contributor
  • **
  • Posts: 284
  • Country: nz
  • RF and Analog Electronics Enthusiast
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #11 on: September 15, 2017, 11:32:53 pm »
The darker reality is that a fully functional analogue oscilloscope isn't going to happen EASILY for $50 in Australia, or anywhere else unless you've got a bottled Genie granting wishes  :clap:

Seriously consider spending upwards of $120 to $250 for a fully functional analogue oscilloscope owned by someone moving on or upgrading,
that's looked after it, and not scared to demo it working properly or let you have a tweak.

Half trashed or intemittent oscilloscopes are more trouble than they're worth for a newb, hobbyist, repair tech or a EE that just wants to get on with it

Do the math: how much is a knackered $50 cro going to cost in time, and parts if you can get them|O
AND access them on the board without banging up other parts, avoiding sensitive 'unobtanium' components, 2000 volt zaps and much higher voltages.  :o

If the calibration is miles off, and troubleshooting and probing waveforms via a service manual on a faulty device or any DUT, you are SOL in any direction.  :-[


$50 oscilloscopes are great for repair people that can fix and calibrate them, keep a couple (or MORE! lol) for themselves,

then resell at $120 to $250 to users that need to get work done, not crossing their fingers their test gear is working


It saves these great pieces of kit from the landfills, puts a few dollars in the sellers and repairers pockets,

and buyers get a classic WORKING oscilloscope for the price of a decent multimeter (or 2 tanks of petrol) 

especially good news if cheap DSLows don't quite do it for them,

which may one day come in handy for practicing topedoes and dropkicks in the back yard


Do yourself a favour and make sure your first analogue oscilloscope is a WORKING one and avoid disappointment. 
Mine was a used  -everything working-  Trio-Kenwood 15mhz dual channel, still kicking goals 20+ years later   :-+


Yes! It is really not that easy to find cheap (but good) second hand gear in AU, let alone NZ.
You really need patience if you want to get a great bargain. I bought my first cro here from our local auction site called "Trade Me" for ~NZ$56. But it was not that easy to find it. (I did not consider eBay because shipping will kill you :() Basically, I started searching for oscilloscopes last December and there were no scopes to be found. (there were dso's of course, but to expensive for me) It was already March but still no luck (well there were some occasional tek cros, but they're over $150). Until it was May when somebody posted a leader scope with a starting bid of $30. Nobody bid on it until the closing hour (it closed at 7AM on a wednesday and there were only 3 bidders :phew:) and then it was finally mine! Yay! ...After all the six months I have waited :) :D
« Last Edit: September 15, 2017, 11:35:11 pm by bjcuizon »
Don't mess with an Electronics Engineer, it Megahertz!
 

Offline Electro Detective

  • Super Contributor
  • ***
  • Posts: 2093
  • Country: au
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #12 on: September 16, 2017, 12:04:15 am »
I must be missing something  :-// 

Why wait around weeks or months in anticipation (and frustration)  to score a POSSIBLE bargain (or lemon  :horse:)   that others are also competing for   :box: :box:

when a few dollars more gets a working oscilloscope on your workbench NOW and get immediate work done and or learning experience/fun out of it   :-+


Is it worth the internet time and electricity wasted, waiting around for the elusive $50 lucky dip ?  Better odds blindfold betting at any racetrack imo


No thanks, I still pay top dollar for a fully working scope/s, and get top dollar back if/when I sell as fully working.

I must be in a minority that saves a few dollars to get something that's verified working,
though I'm no stranger to basic oscilloscope repair and calibration 'IF' I have no choice
..or need ANOTHER headbanging challenge  |O  on a rainy weekend     ;D

 
 

Offline Smokey

  • Super Contributor
  • ***
  • Posts: 1582
  • Country: us
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #13 on: September 16, 2017, 01:00:51 am »
Ya.  Just like 4 years ago and the previous drive time video, I disagree.  The only person who I could honestly recommend going on ebay and buying an ancient analog scope as their First/Only scope would be like a classic car mechanic or something where they may need to look at an analog tach signal twice a year or something.

If you are starting out and plan on sticking with this electronics thing, then you are EXACTLY the person who need to buy a DSO.  Any (modern) DSO.  The cheapest Owon scope will be infinitely more useful than an ancient analog scope.  People new to electronics don't spend a significant amount of time working EXCLUSIVELY in the analog world anymore.  It doesn't help that someone new searching ebay is completely unqualified for determining scope quality or functionality of something 30-40 years old.

If you plan on doing any activity (not just electronics) for a significant amount of time, never start out buying the absolute cheapest thing to "just start out".  You will spend more money (and quickly) once you outgrow the cheap crap.  If you were to buy any Rigol scope, it would most likely not get outgrown for many many years unlike an old analog scope which if you are serious you will outgrow in months if not weeks.  Save up.  Mow lawns for another month.  Whatever.  Spend the $350.   

Do you want to work on one of those "Arduino" things?  Nope, analog scope won't be much help. 
Want to figure out why a serial port isn't working?  Nope, analog scope won't be much help. 
Are you a HAM and are you making a dead bug Manhattan style copper board receiver for some specific frequency??? Bingo!!!!, analog scope is for you!  But at that point you already knew that. 

Don't get sucked into this analog scope thing.  The one and only use for a classic analog oscilloscope (hopefully a Tek 7000 series mainframe) is to make your lab look more bad ass by sitting in the corner collecting dust.

https://www.eevblog.com/forum/beginners/help-on-choosing-my-first-oscilloscope/msg153113/#msg153113
https://www.eevblog.com/forum/beginners/do-you-need-both-analogue-and-digital-scopes-for-your-lab/msg194845/#msg194845
https://www.eevblog.com/forum/blog/eevblog-926-introduction-to-the-oscilloscope/msg1034348/#msg1034348

It's a shame it was 35 minutes into the 36 minue video before Dave made the comment that you should probably not buy an analog scope and save your money for a proper DSO. 
« Last Edit: September 16, 2017, 01:49:49 am by Smokey »
 
The following users thanked this post: Someone, thm_w, Frank

Offline eugenenine

  • Frequent Contributor
  • **
  • Posts: 784
  • Country: us
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #14 on: September 16, 2017, 01:09:42 am »
I picked up a Tek 2205 for $40 then found a 2211 for $50.  I need to re-sell the 2205 now.

I'm just re-starting and the old analog works so far.  I figure it will work until I can afford better then I can re-sell it to someone else needing one.
 

Offline bjcuizon

  • Frequent Contributor
  • **
  • Posts: 284
  • Country: nz
  • RF and Analog Electronics Enthusiast
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #15 on: September 16, 2017, 01:18:22 am »
I must be missing something  :-// 

Why wait around weeks or months in anticipation (and frustration)  to score a POSSIBLE bargain (or lemon  :horse:)   that others are also competing for   :box: :box:

when a few dollars more gets a working oscilloscope on your workbench NOW and get immediate work done and or learning experience/fun out of it   :-+

Is it worth the internet time and electricity wasted, waiting around for the elusive $50 lucky dip ?  Better odds blindfold betting at any racetrack imo

No thanks, I still pay top dollar for a fully working scope/s, and get top dollar back if/when I sell as fully working.

I must be in a minority that saves a few dollars to get something that's verified working,
though I'm no stranger to basic oscilloscope repair and calibration 'IF' I have no choice
..or need ANOTHER headbanging challenge  |O  on a rainy weekend     ;D
Well, I was not in a hurry of getting a scope. And at least it was working on arrival, it displayed a trace and it seems to be taken out of a university here.
I was new to scopes back then and from all those months, I learnt what kind of ballpark price would something go for, and all sorts of stuff as well. I also downloaded some scope sim apps like keysight's one so I could familiarize myself with the controls. It was a great learning experience overall.
Don't mess with an Electronics Engineer, it Megahertz!
 

Offline joseph nicholas

  • Frequent Contributor
  • **
  • Posts: 345
  • Country: mx
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #16 on: September 16, 2017, 02:30:06 am »
The reality is buying a 30 or 40 year old oscilloscope is probabily a waste of time and money.  Even the humble DSO 138 is a better choice than the trickers you will find on ebay.  There are some who are trying to make a living by selling these things and they are way ahead of the young and nieve buyers.  Jones is a toady for the man no doubt.  What motivates Jones is the almighty dollar.
 

Offline Electro Detective

  • Super Contributor
  • ***
  • Posts: 2093
  • Country: au
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #17 on: September 16, 2017, 02:52:15 am »
As a newb with a first used WORKING analogue scope, purchased at a very fair price from previous owner who also gave me some user tips and freebie electronics, I quickly mastered it,
learned more about electronics etc and used it as a sort of reference for other used scopes that followed, to test, repair and calibrate them. As mentioned before, that scope is still going strong 20 years later.

Had I bought a knackered $50 job, I may have been discouraged, disappointed or asked a musician friend shooting a band video to toss it out of a hotel room
and perhaps missed out on the convenience and usefulness of a scope sooner than later/never

Good luck sitting in front of the box surfing Ebay for an elusive snag guys,

life is short and there's lots of probing to do NOW  :-/O

rather than waste it flogging a suss scope    :horse: :horse: :horse:   to get it to display anything  :-BROKE 

and panel beating ones dented 'bargain' ego   :-[   


i.e. don't be too cheap in life (unless you're a pro like me)      ;D



« Last Edit: September 16, 2017, 08:46:11 am by Electro Detective »
 

Offline Tony_G

  • Frequent Contributor
  • **
  • Posts: 581
  • Country: us
  • Checkout my old test gear channel (link in sig)
    • TGSoapbox
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #18 on: September 16, 2017, 04:02:24 am »
I can't comment on this from the perspective of a new hobbyist with limited experience but I needed to acquire an old analog scope because I had a test case that needed the Z axis (non of my other scopes worked properly w.r.t the DUT service guide).

I bought 2 Tektronix 2235 for US$125 that ended up only needing a tweak on the vertical pots and a twist of the CRT magnets.

So I think it is possible but you do need to have a little "Faith" rather than "proof"

TonyG

Offline thermistor-guy

  • Regular Contributor
  • *
  • Posts: 206
  • Country: au
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #19 on: September 16, 2017, 04:31:55 am »
I bought a Tektronix 2246 (4-ch, 100 MHz) on Ebay some years ago, as my first personal oscilloscope. It was NOS, US Gov. surplus, with its contract label still on the side. Obviously not $50.

I have seen (at work) DSOs show misleading traces, due to spurious oscillations and anomalies on supposedly "low frequency" signals, so I specifically wanted an analog scope before I bought a personal DSO.

Analog scopes are great if you need to verify signal integrity in circuits like oscillators; power supplies; and amplifiers.

If you are a beginner on a budget, then yeah, a DSO gets you started, and should give you easy waveform capture and data/image transfer to your PC. Later, you can include the DSO in a personal automated test system, if your interests run in that direction.

Ideally, plan to get both at some stage - an analog scope plus a DSO.
 

Offline Brumby

  • Supporter
  • ****
  • Posts: 9208
  • Country: au
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #20 on: September 16, 2017, 10:57:17 am »
The reality is buying a 30 or 40 year old oscilloscope is probabily a waste of time and money.  Even the humble DSO 138 is a better choice than the trickers you will find on ebay.
 
I have a 15MHz Hitachi V152B circa 1980.  I have a DSO138 circa last year.

There is no comparison.  Not even close.  The DSO138 is a toy - a useful toy - but a toy nonetheless.

Quote
There are some who are trying to make a living by selling these things and they are way ahead of the young and nieve buyers.

Yes, there are sellers like that - but there are also sellers that are above board.  Picking out the good ones is the challenge.

Quote
Jones is a toady for the man no doubt.  What motivates Jones is the almighty dollar.
Really?

 

Offline djos

  • Supporter
  • ****
  • Posts: 947
  • Country: au
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #21 on: September 16, 2017, 09:35:19 pm »
I've thought about buying an old analogue scope, but I'm seriously thinking about buying either a Siglent SDS1102CML 100MHz Dual-Channel for low $300's or saving up a bit more and getting a Rigol 1054z quad channel unit for an extra $300. Scopes are bloody expensive in Australia.
The impossible often has a kind of integrity which the merely improbable lacks.

Visit my Tindie store for Tandy 1000 Adapters for EX, HX, SX, SL, TX & TL etc
 

Offline nctnico

  • Super Contributor
  • ***
  • Posts: 17615
  • Country: nl
    • NCT Developments
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #22 on: September 17, 2017, 06:23:05 pm »
Why dick around with old analog junk scopes if you can buy things like these for less than $55 including shipping?

http://www.ebay.com/itm/DSO112A-Mini-Handheld-Pocket-Digital-Storage-Oscilloscope-TFT-Touch-Screen-I7Q8-/401088702102

Or this one (although you'll need a PC to control it):

http://www.ebay.com/itm/Hantek-6022BE-20MHz-Handheld-2-Channels-Digital-Portable-PC-USB-Oscilloscope-/332378813681

IMHO these are much better investments if money is an issue than to get a boatanchor which can turn into a repair project at any time.
« Last Edit: September 17, 2017, 06:25:42 pm by nctnico »
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline Gyro

  • Super Contributor
  • ***
  • Posts: 4623
  • Country: gb
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #23 on: September 17, 2017, 06:29:08 pm »
Errr, was that a joke?  :o  :-//

Single channel only, 2MHz bandwidth, 5Msps max. Clip leads instead of scope probe....

https://www.eevblog.com/forum/testgear/has-this-been-discussed-before-a-'decent'-portable-oscope-for-$70/


EDIT: I see you added the Hantek, only 20MHz, 48Msps (depending on whether the PC s/w can keep up). The Hantek is just a dumb streamer with limited triggering in s/w, it doesn't even have an AC coupling option.

At least the DSO138 is a cheap useful toy.
« Last Edit: September 17, 2017, 06:58:37 pm by Gyro »
Chris

"Victor Meldrew, the Crimson Avenger!"
 

Offline Lightages

  • Supporter
  • ****
  • Posts: 4295
  • Country: ca
  • Canadian po
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #24 on: September 17, 2017, 07:42:59 pm »
Seeing as the thread I started is being referenced, I would like to say something.

In no way should the DSO112A be considered as a replacement for a real desktop analog scope. It is a different beast, possibly a useful portable scope for some purposes, and a cheap digital scope. The lowest analog scope one can buy, usually, is 20MHz. This is 10x higher than the DSO112A.

IMHO, a $50 to $100 analog scope is far superior for anyone to use over the DSO112A. If you need a scope to carry out to your car, or trouble shoot something while on a ladder, and the DSO112A has sufficient bandwidth, then it is far superior to any CRT analog scope in cases like those.
« Last Edit: September 18, 2017, 04:08:29 am by Lightages »
 
The following users thanked this post: Gyro

Offline Gyro

  • Super Contributor
  • ***
  • Posts: 4623
  • Country: gb
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #25 on: September 17, 2017, 08:09:09 pm »
In the hope of making some sort of sense of the intention behind nctnico's post...

The lowest cost USB scope that I would suggest as a viable alternative to a $50 ebay analogue scope, for less demanding applications, would be the VDS1022.  Then you get  25MHz, 100Msps on 2 channels, with sufficient hardware and firmware in the scope itself to do proper hardware triggering (not just edge), AC/DC coupling, and actually achieve its quoted maximum sampling rates with minimal loading on the PC.

Unfortunately it fails the $50 test by nearly a factor of two:  https://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=VDS1022&_sop=15
« Last Edit: September 17, 2017, 08:21:52 pm by Gyro »
Chris

"Victor Meldrew, the Crimson Avenger!"
 

Offline nctnico

  • Super Contributor
  • ***
  • Posts: 17615
  • Country: nl
    • NCT Developments
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #26 on: September 17, 2017, 08:30:48 pm »
I'm thinking back to when I was a teenager and had a dual channel 20MHz analog scope which could only do edge triggering. No single shot, no measurements, no screendumps.... When given the choice back then between the options in my previous post and the 20MHz analog scope I'm not so sure I would have choosen the analog scope. A DSO (even if it is a limited one or needs a PC) offers a lot of possibilities an analog oscilloscope doesn't have.
Actually someone wrote Python software for the Hantek 6022BE I linked to earlier ( https://github.com/rpcope1/Hantek6022API ). With some tinkering the possibilities are endless.
« Last Edit: September 17, 2017, 09:45:28 pm by nctnico »
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline David Hess

  • Super Contributor
  • ***
  • Posts: 9902
  • Country: us
  • DavidH
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #27 on: September 17, 2017, 11:42:24 pm »
I am in the US so deals and especially Tektronix deals are relatively easy to get.  My best buys have been a completely working Tektronix 2230 (100 MHz, 20MS/s, Peak Detection) on Ebay for $60 and a working Tektronix 547 (50 MHz, alternate sweep, super sharp CRT) with plug-ins and cart locally for $50.

An analog oscilloscope is suitable for a majority of applications and there is a minority of applications where an analog oscilloscope is better than a DSO.  However a novice is unlikely to be able to recognize their own requirements and evaluate a used instrument making a new but expensive DSO more desirable.
 

Offline Electro Detective

  • Super Contributor
  • ***
  • Posts: 2093
  • Country: au
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #28 on: September 17, 2017, 11:53:33 pm »
FWIW: This advice is strictly for newbs and greybeards returning to the game, seeking to spend their initial start up pennies wisely:  :-+

Why stuff around with a cheap DSLOw, when the real action is with a cheap fully WORKING classic analogue oscilloscope?

Quickly switch and dial up waveforms, instead of ploughing through menus with quirky toy knobs, waiting on software bugs updates that may never come or they bug fix one issue and create ten more,
contemplating noisy fan replacements,
praying it still works past the warranty period because you know deep down it's a   'not worth fixing'   throwaway job once it dies 

Get a cro, and get on with it! 

$120 > $250 spent on a good fully working scope won't send you to the poor house (in Australia)


In most cases (99%) a $50 cro will get you OTHER PEOPLES PROBLEMS and lost bench real estate
(or shed space waiting to toss it, or have another futile go at fixing the sucker, if you can allocate more time to waste... :-[)
 

Offline buck converter

  • Regular Contributor
  • *
  • Posts: 160
  • Country: us
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #29 on: September 18, 2017, 12:11:07 am »
ATTENTIONS TEENS: You are special when it comes to getting these analog scopes. This past summer I went to a generic STEM camp at a local university. Walk past a dumpster loaded with scopes. Now I already had a CRO ::), but I knew I could sell these if I could get my hands on them, and raise money for my robotics club. I only walked out with one, a working Tek 2235. For free :-+. What I am trying to say is that if your a teen, ask local universities with electrical engineering programs if they don't need them. It doesn't cost any money to ask, and could build connections, especially if you are already attending a STEM camp :-+.
Just me and my scope.
 

Offline eugenenine

  • Frequent Contributor
  • **
  • Posts: 784
  • Country: us
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #30 on: September 18, 2017, 12:13:22 am »
Always sad to see stuff like that in a dumpster.
Anyone ever played with one of these http://www.gabotronics.com/development-boards/xmega-xprotolab.htm
 

Offline Smokey

  • Super Contributor
  • ***
  • Posts: 1582
  • Country: us
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #31 on: September 18, 2017, 02:49:26 am »
...An analog oscilloscope is suitable for a majority of applications and there is a minority of applications where an analog oscilloscope is better than a DSO. 

I would like to hear your list, even a minority list, where an analog scope is better than a DSO.  Not just equivalent, or sufficient, but better.

Also saying an analog scope is suitable for a MAJORITY of applications is not very truthful.  The majority of scope application these days are NOT looking at repetitive signals, which makes an analog scope not suitable (unless you suggest everyone also gets one of those Tek camera adapters to take triggered pictures).  The world of embedded systems requires a DSO (or a lot of guessing).
 

Offline boffin

  • Supporter
  • ****
  • Posts: 861
  • Country: ca
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #32 on: September 18, 2017, 04:10:12 am »
There's going to be plenty of arguments

"I can't find one for $50"
"A digital USB scope is useless"
"Dave does these videos for the money"


Well, there might be some truth to the first two, I'm pretty sure Dave isn't getting rich from his youtube channel.  $40k last year (checkout eevblog# 959) - that's peanuts when you compare his expenses.

However, keep looking. 
I bought a used Analog Discovery for C$100; and it's really useful. REALLY.
I bought a broken Philips 3216 (35MHz) for C$10, and replaced a 50c trimmer to get it working.  I did spend $15 on some de-oxit.  Still, C$25 total

They both have their place.

There's a Tek 2213 (60Mhz) on the local Craigslist right now for C$200 in what looks like great shape. It's been there a while, so I'll bet you could get it for C$150. Sure it's not $50, but it's still 1/3 the price of a new Rigol; and probably way more scope than most beginners need.

People take things way too literally. I'm sure you can find a scope for $50, it just might take some time - Dave is trying to make a point. 
However for double that (or a tiny bit more), you could have a [nice] scope by the end of the day if you really wanted one.
 
The following users thanked this post: Electro Detective

Offline nctnico

  • Super Contributor
  • ***
  • Posts: 17615
  • Country: nl
    • NCT Developments
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #33 on: September 18, 2017, 08:36:59 am »
An analog oscilloscope is suitable for a majority of applications and there is a minority of applications where an analog oscilloscope is better than a DSO.  However a novice is unlikely to be able to recognize their own requirements and evaluate a used instrument making a new but expensive DSO more desirable.
That is a way too generic statement. What I hated about my 20MHz analog scope was that it absolutely sucked at showing slow waveforms and I needed to count divisions + do math to get amplitude, time, frequency, etc.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline David Hess

  • Super Contributor
  • ***
  • Posts: 9902
  • Country: us
  • DavidH
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #34 on: September 18, 2017, 11:14:30 am »
...An analog oscilloscope is suitable for a majority of applications and there is a minority of applications where an analog oscilloscope is better than a DSO.

I would like to hear your list, even a minority list, where an analog scope is better than a DSO.  Not just equivalent, or sufficient, but better.

Measuring RMS noise is one of them that I keep coming up against.  In theory any DSO with RMS measurement capability should be able to do this (it is trivial in the digital domain) however DSOs which make measurements on the processed display record which are apparently a majority now cannot.  And unfortunately no DSO yet duplicates the response of an analog CRT so they cannot do tangential RMS measurement either as an alternative.

Finding snivets is another problem that I have run up against with DSOs.  Again, most should be able to do this however the processing used for index grading the display tends to cover them up when it should not.  This is an aspect of DSO displays looking noisier than analog displays whether they truly are noisier or not.

Quote
The majority of scope application these days are NOT looking at repetitive signals, ...

We will have to disagree on this point and especially so since non-storage oscilloscopes can still be used in many cases on non-repetitive signals.

That is a way too generic statement. What I hated about my 20MHz analog scope was that it absolutely sucked at showing slow waveforms and I needed to count divisions + do math to get amplitude, time, frequency, etc.

Obviously a storage oscilloscope is indispensable at low repetition rates but of all of the applications, how many require this?
 

Online Fungus

  • Super Contributor
  • ***
  • Posts: 9952
  • Country: 00
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #35 on: September 18, 2017, 12:09:17 pm »
Measuring RMS noise is one of them that I keep coming up against.  In theory any DSO with RMS measurement capability should be able to do this (it is trivial in the digital domain) however DSOs which make measurements on the processed display record which are apparently a majority now cannot. 

Maybe you underestimate the processing power needed for that (and if they did a slow-updating display you'd just complain about that instead).

You can:
a) Download the memory to a PC for processing with nothing more than an Ethernet cable and a free program.
b) Use a TRMS multimeter, they cost about $15 these days and are the correct tool for the job. DSOs are for looking at wiggly lines and getting approximate measurements.
 

Offline Smokey

  • Super Contributor
  • ***
  • Posts: 1582
  • Country: us
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #36 on: September 18, 2017, 06:54:41 pm »
...
Finding snivets is another problem that I have run up against with DSOs.  Again, most should be able to do this however the processing used for index grading the display tends to cover them up when it should not.  This is an aspect of DSO displays looking noisier than analog displays whether they truly are noisier or not.
...

Never heard of a Snivet before.   I had to look this up. 
http://amfone.net/Amforum/index.php?topic=35557.0

"One of the phenomena that has appeared in the image reproduced in the television receiver is known as the snivet. Snivets are thin parallel vertical lines which may appear at one or more positions of the reproduced image. lt has been suggested that the production of such thin vertical lines is due to Barlthausen oscillations developed in the horizontal output tube. Barlrhausen oscillations may be produced in a tube when a positive electrode is arranged between two more negative electrodes. The electrons present in the tube are repelled by the more negative electrodes back toward the positive electrode. The oscillations caused by the alternate attraction and repelling of electrons occurs in a frequency range determined by the dimensions and spacing of the electrodes and the potentials applied thereto. Such oscillations may produce radio frequency radiation in the video carrier frequency range of the television receiver. T is radiation will then be detected and pass through such receiver in substantially the same manner as the video signal. The received radiation is then reproduced on the cathode ray screen in the form of the above-referred to thin vertical lines. "


So it sounds like one of your examples for when ancient analog scopes is better is essentially when working on other ancient analog scope CRTs?  Can you even buy a CRT TV now?  Can't say I can think of a lot of other CRT uses these days. 
 

Offline kalel

  • Frequent Contributor
  • **
  • Posts: 880
  • Country: 00
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #37 on: September 18, 2017, 07:03:02 pm »
So it sounds like one of your examples for when ancient analog scopes is better is essentially when working on other ancient analog scope CRTs?  Can you even buy a CRT TV now?  Can't say I can think of a lot of other CRT uses these days.

You probably can, I think I saw some smaller, low end units being sold in some shop (don't quote me on that). As for uses, maybe game emulators? If some were originally intended for a CRT, and you wanted more faithful reproduction, I doubt that the filters that some emulation tools have really reproduce CRT's faithfully on an LCD. That said, it is much easier to look at a quality LCD screen, even if older games don't always look that great due to their resolution.
 
 

Offline b_force

  • Super Contributor
  • ***
  • Posts: 1180
  • Country: 00
    • One World Concepts
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #38 on: September 18, 2017, 07:06:44 pm »
An analog oscilloscope is suitable for a majority of applications and there is a minority of applications where an analog oscilloscope is better than a DSO.  However a novice is unlikely to be able to recognize their own requirements and evaluate a used instrument making a new but expensive DSO more desirable.
That is a way too generic statement. What I hated about my 20MHz analog scope was that it absolutely sucked at showing slow waveforms and I needed to count divisions + do math to get amplitude, time, frequency, etc.
I guess that's being considered as minor things maybe?
Yes, I also like digital scopes much better for these reasons.
But on the other side, back in the days we even didn't have that luxury?

So in a sense I totally agree with that statement a lot.
I see to many people bragging about their fancy equipment, but most of the time they don't even using it.
Or even worse, don't even take people serious anymore with cheaper equipment.
The fact that someone is on a tight budget, doesn't mean that they don't know what they are doing.
(in fact, it's mostly the opposite)

Ones again, people go into details. I think everyone can see/read that digital scopes have a lot more luxury.
But, hey, if you just wanna develop stuff and you're on a tight budget, there are options available
In fact, in most cases you only wanna see if signals are coming through, so you don't even need math functions.

Only thing I would like to add to the video, is that it's not entirely fair.
The cheap scopes are all based in the US or Asia. So that means you have to pay a lot of import tax and shipping.
Second hand market in EU is actually pretty bad to be honest.
People ask ridiculous prices or trash it. There is nothing in between.
« Last Edit: September 18, 2017, 07:10:21 pm by b_force »
"If you can't explain it simply (or at all), you don't understand it well enough." A. Einstein

http://www.oneworldconcepts.com/ | http://www.soundprojects.com
 

Offline nctnico

  • Super Contributor
  • ***
  • Posts: 17615
  • Country: nl
    • NCT Developments
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #39 on: September 18, 2017, 08:12:46 pm »
An analog oscilloscope is suitable for a majority of applications and there is a minority of applications where an analog oscilloscope is better than a DSO.  However a novice is unlikely to be able to recognize their own requirements and evaluate a used instrument making a new but expensive DSO more desirable.
That is a way too generic statement. What I hated about my 20MHz analog scope was that it absolutely sucked at showing slow waveforms and I needed to count divisions + do math to get amplitude, time, frequency, etc.
I guess that's being considered as minor things maybe?
Yes, I also like digital scopes much better for these reasons.
But on the other side, back in the days we even didn't have that luxury?

So in a sense I totally agree with that statement a lot.
I see to many people bragging about their fancy equipment, but most of the time they don't even using it.
Why would you have to use fancy features every time? What is important is that if you need it, it is there and it will make life easier. For example: I have a very nice Tektronix logic analyser but it is only on for a couple of hours per year. So I don't need it a lot but it is darn handy to have it available and be able to use it when necessary.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline b_force

  • Super Contributor
  • ***
  • Posts: 1180
  • Country: 00
    • One World Concepts
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #40 on: September 18, 2017, 08:36:09 pm »
An analog oscilloscope is suitable for a majority of applications and there is a minority of applications where an analog oscilloscope is better than a DSO.  However a novice is unlikely to be able to recognize their own requirements and evaluate a used instrument making a new but expensive DSO more desirable.
That is a way too generic statement. What I hated about my 20MHz analog scope was that it absolutely sucked at showing slow waveforms and I needed to count divisions + do math to get amplitude, time, frequency, etc.
I guess that's being considered as minor things maybe?
Yes, I also like digital scopes much better for these reasons.
But on the other side, back in the days we even didn't have that luxury?

So in a sense I totally agree with that statement a lot.
I see to many people bragging about their fancy equipment, but most of the time they don't even using it.
Why would you have to use fancy features every time? What is important is that if you need it, it is there and it will make life easier. For example: I have a very nice Tektronix logic analyser but it is only on for a couple of hours per year. So I don't need it a lot but it is darn handy to have it available and be able to use it when necessary.
I am not saying there is anything wrong with it?
I totally agree with you, but I am just saying it's pure luxury.
So if you go back to the basics, you don't really need it.
Which is good to know for people on a tight budget for example.
"If you can't explain it simply (or at all), you don't understand it well enough." A. Einstein

http://www.oneworldconcepts.com/ | http://www.soundprojects.com
 

Online Fungus

  • Super Contributor
  • ***
  • Posts: 9952
  • Country: 00
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #41 on: September 18, 2017, 09:00:08 pm »
What I hated about my 20MHz analog scope was that it absolutely sucked at showing slow waveforms and I needed to count divisions + do math to get amplitude, time, frequency, etc.

I don't think anybody would deny that CROs are better looking and DSOs or more fun to use. I love the green traces, they look awesome compared to my Rigol's pixels.

But ... they do show a lot less information once you go outside their optimal settings and being able to record the waveform and zoom in on a DSO is invaluable.

CROs are perfect for looking at repetitive signals but that's not really the world we live in any more. The modern world is full of microcontrollers and digital signals and in that world the DSO is king
 

Offline nctnico

  • Super Contributor
  • ***
  • Posts: 17615
  • Country: nl
    • NCT Developments
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #42 on: September 18, 2017, 09:07:02 pm »
An analog oscilloscope is suitable for a majority of applications and there is a minority of applications where an analog oscilloscope is better than a DSO.  However a novice is unlikely to be able to recognize their own requirements and evaluate a used instrument making a new but expensive DSO more desirable.
That is a way too generic statement. What I hated about my 20MHz analog scope was that it absolutely sucked at showing slow waveforms and I needed to count divisions + do math to get amplitude, time, frequency, etc.
I guess that's being considered as minor things maybe?
Yes, I also like digital scopes much better for these reasons.
But on the other side, back in the days we even didn't have that luxury?

So in a sense I totally agree with that statement a lot.
I see to many people bragging about their fancy equipment, but most of the time they don't even using it.
Why would you have to use fancy features every time? What is important is that if you need it, it is there and it will make life easier. For example: I have a very nice Tektronix logic analyser but it is only on for a couple of hours per year. So I don't need it a lot but it is darn handy to have it available and be able to use it when necessary.
I am not saying there is anything wrong with it?
I totally agree with you, but I am just saying it's pure luxury.
So if you go back to the basics, you don't really need it.
Which is good to know for people on a tight budget for example.
The thing is: nowadays you don't have to compromise. There are tons of cheap DSOs out there. I only linked to the first two ones I found on Aliexpress.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Online Fungus

  • Super Contributor
  • ***
  • Posts: 9952
  • Country: 00
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #43 on: September 18, 2017, 09:07:29 pm »
But, hey, if you just wanna develop stuff and you're on a tight budget, there are options available
In fact, in most cases you only wanna see if signals are coming through, so you don't even need math functions.

I don't think I've ever used a math function, I do an awful lot of capturing/zooming though.

Only thing I would like to add to the video, is that it's not entirely fair.
The cheap scopes are all based in the US or Asia. So that means you have to pay a lot of import tax and shipping.
Second hand market in EU is actually pretty bad to be honest.
People ask ridiculous prices or trash it. There is nothing in between.

Yep. Buying in Europe is a completely different story. I think Germany is maybe the best place to look but even then there's bugger all compared to the USA.
 

Offline Gyro

  • Super Contributor
  • ***
  • Posts: 4623
  • Country: gb
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #44 on: September 18, 2017, 09:31:24 pm »
The thing is: nowadays you don't have to compromise. There are tons of cheap DSOs out there. I only linked to the first two ones I found on Aliexpress.

You just need to make sure that you don't link products that drop below the 'frustration threshold' - that way lies misery and buyer's remorse.  ;)
« Last Edit: September 18, 2017, 09:34:12 pm by Gyro »
Chris

"Victor Meldrew, the Crimson Avenger!"
 

Offline b_force

  • Super Contributor
  • ***
  • Posts: 1180
  • Country: 00
    • One World Concepts
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #45 on: September 18, 2017, 09:46:39 pm »
I still found a "$50" analog Philips or so, a whole lot better than these cheapo USB thingies.
Like I said, I think 50 bucks is a little bit to positive, but still, you can't find a decent digital scope between 50-100 bucks.
But maybe that's just purely subjective.

It's frustrating though, these USB scope things do have heaps of potential.
They just screw it up in the software, which is to unfortunate.
"If you can't explain it simply (or at all), you don't understand it well enough." A. Einstein

http://www.oneworldconcepts.com/ | http://www.soundprojects.com
 

Offline Gyro

  • Super Contributor
  • ***
  • Posts: 4623
  • Country: gb
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #46 on: September 18, 2017, 09:52:26 pm »
I still set the lower limit of  'acceptability' (of USB models) at the VDS1022.  Below that, the Hantek, Sainsmart etc. are horribly compromised, either in H/W, S/W or meeting their specified performance.
« Last Edit: September 18, 2017, 09:57:36 pm by Gyro »
Chris

"Victor Meldrew, the Crimson Avenger!"
 

Offline b_force

  • Super Contributor
  • ***
  • Posts: 1180
  • Country: 00
    • One World Concepts
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #47 on: September 18, 2017, 10:19:10 pm »
I still set the lower limit of  'acceptability' (of USB models) at the VDS1022.  Below that, the Hantek, Sainsmart etc. are horribly compromised, either in H/W, S/W or meeting their specified performance.
Agree, although the isolated variation (or USB isolator) would be very wise.

My personal main issue is just the interface.
I think it just doesn't really work with a mouse when measuring live stuff.
I like to use knobs, works much quicker and more intuitive
You could probably get away with a DAW controller or so, but than you can better buy a better scope.
Or you need to build something yourself of course :)  8)
"If you can't explain it simply (or at all), you don't understand it well enough." A. Einstein

http://www.oneworldconcepts.com/ | http://www.soundprojects.com
 

Offline David Hess

  • Super Contributor
  • ***
  • Posts: 9902
  • Country: us
  • DavidH
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #48 on: September 19, 2017, 01:29:22 am »
Measuring RMS noise is one of them that I keep coming up against.  In theory any DSO with RMS measurement capability should be able to do this (it is trivial in the digital domain) however DSOs which make measurements on the processed display record which are apparently a majority now cannot.

Maybe you underestimate the processing power needed for that (and if they did a slow-updating display you'd just complain about that instead).

You are joking, right?  I hope you are joking.

Quote
You can:
a) Download the memory to a PC for processing with nothing more than an Ethernet cable and a free program.

I have done it this way before.  At one time I even had my HP calculator programmed to do it with a sampling voltmeter but that was at low frequencies.

Quote
b) Use a TRMS multimeter, they cost about $15 these days and are the correct tool for the job. DSOs are for looking at wiggly lines and getting approximate measurements.

Multimeters do not have nearly the bandwidth of even a slow oscilloscope.  The bandwidth requirements are usually modest but multimeters are not even close.

...
Finding snivets is another problem that I have run up against with DSOs.  Again, most should be able to do this however the processing used for index grading the display tends to cover them up when it should not.  This is an aspect of DSO displays looking noisier than analog displays whether they truly are noisier or not.
...

...

So it sounds like one of your examples for when ancient analog scopes is better is essentially when working on other ancient analog scope CRTs?  Can you even buy a CRT TV now?  Can't say I can think of a lot of other CRT uses these days.

A snivet is a negative resistance parasitic oscillation.  It most commonly shows up in emitter/source followers.  The name originated from the negative resistance oscillation in a sweep tetrode at low anode voltage which showed up as described by your link as a visual disturbance on television CRTs.
 

Offline ez24

  • Super Contributor
  • ***
  • Posts: 3092
  • Country: us
  • L.D.A.
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #49 on: September 19, 2017, 02:17:22 am »
The reality is buying a 30 or 40 year old oscilloscope is probabily a waste of time and money. 

Was for me - twice.
YouTube and Website Electronic Resources ------>  https://www.eevblog.com/forum/other-blog-specific/a/msg1341166/#msg1341166
 

Offline boffin

  • Supporter
  • ****
  • Posts: 861
  • Country: ca
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #50 on: September 19, 2017, 03:51:10 am »
Apparently any of us that did work 30 yrs ago -- with analog only (no storage) scopes -- weren't doing real electronics; if you are to believe a lot of people in this thread.
 
The following users thanked this post: Electro Detective

Offline Brumby

  • Supporter
  • ****
  • Posts: 9208
  • Country: au
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #51 on: September 19, 2017, 04:37:01 am »
I seem to recall doing a fair bit with just a 20Kohm/volt analog meter, a stick soldering iron with a pair of needle nosed pliers, sidecutters and a screwdriver....

Mind you, things have changed.

I didn't have a dozen microprocessor boards in a box on my shelf back then, like I have today...
« Last Edit: September 19, 2017, 04:39:35 am by Brumby »
 

Offline Smokey

  • Super Contributor
  • ***
  • Posts: 1582
  • Country: us
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #52 on: September 19, 2017, 04:56:04 am »
Apparently any of us that did work 30 yrs ago -- with analog only (no storage) scopes -- weren't doing real electronics; if you are to believe a lot of people in this thread.

I've said this all over the forum before.  Mad respect for anyone that was doing electronics back in the day.  You guys actually understood so much more stuff because you had to.  We have it easy now, partly due to cheap powerful gear like modern DSOs. 

Question.  What was the first good logic analyzer that came out? 
 
The following users thanked this post: Electro Detective

Offline Brumby

  • Supporter
  • ****
  • Posts: 9208
  • Country: au
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #53 on: September 19, 2017, 07:31:37 am »
The human brain.
 
The following users thanked this post: boffin, bjcuizon, Electro Detective

Offline Smokey

  • Super Contributor
  • ***
  • Posts: 1582
  • Country: us
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #54 on: September 19, 2017, 08:29:38 am »
I said good logic analyzer.  Based on the news these days, the brain doesn't count.
 

Online Fungus

  • Super Contributor
  • ***
  • Posts: 9952
  • Country: 00
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #55 on: September 19, 2017, 08:43:06 am »
Apparently any of us that did work 30 yrs ago -- with analog only (no storage) scopes -- weren't doing real electronics; if you are to believe a lot of people in this thread.

a) You weren't working in a world full of digital devices so you didn't need storage nearly as much.
b) I've seen all the film camera attachments and stuff you used to use when you actually needed 'storage'.
c) I bet you'd have switched in a heartbeat if today's cheap DSOs were available.

« Last Edit: September 19, 2017, 08:45:44 am by Fungus »
 

Offline Brumby

  • Supporter
  • ****
  • Posts: 9208
  • Country: au
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #56 on: September 19, 2017, 09:29:22 am »
I said good logic analyzer.  Based on the news these days, the brain doesn't count.

It's only a matter of finding somewhere to plug the probes in....
 

Offline nctnico

  • Super Contributor
  • ***
  • Posts: 17615
  • Country: nl
    • NCT Developments
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #57 on: September 19, 2017, 01:08:03 pm »
Apparently any of us that did work 30 yrs ago -- with analog only (no storage) scopes -- weren't doing real electronics; if you are to believe a lot of people in this thread.
I've said this all over the forum before.  Mad respect for anyone that was doing electronics back in the day.  You guys actually understood so much more stuff because you had to.  We have it easy now, partly due to cheap powerful gear like modern DSOs. 
No, it just took more time and self-build tools to measure something. I recall speaking to someone who debugged firmware using a bunch of comparators, adjustable address and LEDs on a board to capture a byte at a specific address.
Quote
Question.  What was the first good logic analyzer that came out?
It wouldn't surprise me if logic analysers have been available since the 50's or 60's. They are not that exotic.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Online Fungus

  • Super Contributor
  • ***
  • Posts: 9952
  • Country: 00
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #58 on: September 19, 2017, 02:20:17 pm »
It wouldn't surprise me if logic analysers have been available since the 50's or 60's. They are not that exotic.

Weren't they built directly into the front panels of most early computers? All those flashing lights...

 

Offline b_force

  • Super Contributor
  • ***
  • Posts: 1180
  • Country: 00
    • One World Concepts
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #59 on: September 19, 2017, 02:25:45 pm »
They were build with a piece of paper and a pencil  ;D
"If you can't explain it simply (or at all), you don't understand it well enough." A. Einstein

http://www.oneworldconcepts.com/ | http://www.soundprojects.com
 

Offline Tony_G

  • Frequent Contributor
  • **
  • Posts: 581
  • Country: us
  • Checkout my old test gear channel (link in sig)
    • TGSoapbox
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #60 on: September 19, 2017, 02:35:29 pm »
Interesting historical view from the HP Memory project:

https://web.archive.org/web/20160304120925/http://hpmemoryproject.org/wb_pages/wall_b_page_12.htm

Using Wayback because the actual site seems to have been taken over by scammers/misconfigured/something as it kept redirecting me to those fake virus popup sites (URLs seem to be all pointing to HPMemory.org instead of HPMemoryProject.org)

TonyG
 
The following users thanked this post: Smokey

Offline Smokey

  • Super Contributor
  • ***
  • Posts: 1582
  • Country: us
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #61 on: September 19, 2017, 11:07:54 pm »
Interesting historical view from the HP Memory project:
https://web.archive.org/web/20160304120925/http://hpmemoryproject.org/wb_pages/wall_b_page_12.htm
...

Sweet link.  That's pretty much what I was wondering.  That progression is pretty amazing.
 

Offline vk6zgo

  • Super Contributor
  • ***
  • Posts: 4846
  • Country: au
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #62 on: September 20, 2017, 01:35:27 am »
Apparently any of us that did work 30 yrs ago -- with analog only (no storage) scopes -- weren't doing real electronics; if you are to believe a lot of people in this thread.

a) You weren't working in a world full of digital devices so you didn't need storage nearly as much.
b) I've seen all the film camera attachments and stuff you used to use when you actually needed 'storage'.
c) I bet you'd have switched in a heartbeat if today's cheap DSOs were available.

 The number of times storage was really needed, I could count on the fingers of one hand.

The Polaroid camera attachments usually were used when checking waveform "specs", rather than to record some fleeting happening.
In fact, they often incorporated a "projected graticule" device which projected a transparency upon the CRT
face.
You fitted the waveform of interest into the reference marks on the image, checked its compliance, & if required,  took a picture .

Those of us who were quite "gung ho"about digital things were in for a horrible shock when the Tek & HP guys came round to demonstrate the first generations of DSOs, as they were virtually unusable for everyday Electronic work, which consisted of a combination of analog & some digital circuitry.

A lot of the stuff Techs do on a day to day basis is to do with signal integrity at a quite a basic level.

"Is the signal there at all ?

"Is it approximately the right level?"

"Is it breaking up, or will it do so if I wiggle the cable, tap the board, etc?"

"Is there a lot of hum on the signal?"

It is nice to be able to see "runt" pulses, read RMS values & all the rest, but this is of more importance to EEs developing stuff which hasn't actually worked yet, than to anyone fixing something which has worked.

Police Officers spend most of their time apprehending speeders, burglars, street drunks, & so on.
The  International Jewel Thieves don't come along very often.





« Last Edit: September 20, 2017, 01:39:45 am by vk6zgo »
 
The following users thanked this post: Electro Detective

Offline Tony_G

  • Frequent Contributor
  • **
  • Posts: 581
  • Country: us
  • Checkout my old test gear channel (link in sig)
    • TGSoapbox
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #63 on: September 20, 2017, 03:22:44 am »
Sweet link.  That's pretty much what I was wondering.  That progression is pretty amazing.

It's a good site and the admin just got back to me saying that he thinks it's corrected.

Personally, I just bought a 16902A & 16902B Logic Analyzers - I'm looking forward to get them and try them out.

TonyG

Offline boffin

  • Supporter
  • ****
  • Posts: 861
  • Country: ca
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #64 on: October 01, 2017, 06:16:28 pm »
And for those looking for the mythical $50 scope; I offer you up this C$50 here in Vancouver on Craigslist right now

https://vancouver.craigslist.ca/bnc/ele/d/hitachi-oscilloscope/6325326081.html
 

Offline bjcuizon

  • Frequent Contributor
  • **
  • Posts: 284
  • Country: nz
  • RF and Analog Electronics Enthusiast
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #65 on: October 02, 2017, 06:47:56 am »
I believe someone on the forum is giving away 4 IIRC..
https://www.eevblog.com/forum/buysellwanted/free-oscilloscopes-for-beginners/
Don't mess with an Electronics Engineer, it Megahertz!
 

Offline guido

  • Regular Contributor
  • *
  • Posts: 207
  • Country: nl
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #66 on: October 02, 2017, 10:34:53 pm »
I would like to hear your list, even a minority list, where an analog scope is better than a DSO.  Not just equivalent, or sufficient, but better.

As a prop in a TV program :popcorn:  Slow timebase, mucho intensity and a slow moving dot on the screen.

 8)
 

Offline Tony_G

  • Frequent Contributor
  • **
  • Posts: 581
  • Country: us
  • Checkout my old test gear channel (link in sig)
    • TGSoapbox
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #67 on: October 02, 2017, 11:17:15 pm »
I would like to hear your list, even a minority list, where an analog scope is better than a DSO.  Not just equivalent, or sufficient, but better.

In general I agree but I did have a scenario for the list:

The reason I acquired an analog scope was for Z-Axis support. The DSOs that I tried (HP 54845A, 54622A, TDS 784D, one other which I can't remember but I borrowed from work) simply didn't display the trace correctly because the HP 8340B Sig Gen expected the Z-axis to work the way the old scopes did.

Sure it is a pretty specific scenario but it is one that I really ran into. I ended up buy a Tek 2235A to address it.

TonyG

Offline Smokey

  • Super Contributor
  • ***
  • Posts: 1582
  • Country: us
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #68 on: October 03, 2017, 03:05:22 am »
I would like to hear your list, even a minority list, where an analog scope is better than a DSO.  Not just equivalent, or sufficient, but better.
...
The DSOs that I tried (HP 54845A, 54622A, TDS 784D, one other which I can't remember but I borrowed from work)
...

I haven't worked with these scopes and I'm not making any judgements about capabilities or anything... Just point out that:
54845A = Manual publication date of 2001
54622A = Manual publication date of 2000
TDS 784D = Manual release date of 1999

That's a technological eternity. 
 
The following users thanked this post: vk6zgo

Online Fungus

  • Super Contributor
  • ***
  • Posts: 9952
  • Country: 00
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #69 on: October 03, 2017, 09:07:11 am »
I would like to hear your list, even a minority list, where an analog scope is better than a DSO.  Not just equivalent, or sufficient, but better.

As a prop in a TV program :popcorn:  Slow timebase, mucho intensity and a slow moving dot on the screen.

 8)

Yep. Decoration.

Decoration, heating the room, filling up large workspaces so that you look busy just by sitting in front of them.

People may go on and on about how precise they are, etc., but they're usually just comparing very expensive CROs with entry level DSOs.

Even then I'm not 100% convinced. Most of the "error" in entry DSOs would be very difficult to see if it weren't for all the measurements to two decimal places on the screen. Most "errors" in CROs are judged by eye against a graticule, so...  :-//
 

Offline Tony_G

  • Frequent Contributor
  • **
  • Posts: 581
  • Country: us
  • Checkout my old test gear channel (link in sig)
    • TGSoapbox
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #70 on: October 03, 2017, 03:48:47 pm »
I haven't worked with these scopes and I'm not making any judgements about capabilities or anything... Just point out that:
54845A = Manual publication date of 2001
54622A = Manual publication date of 2000
TDS 784D = Manual release date of 1999

That's a technological eternity.

Again, I agree but what you're seeing here is the oscilloscope version of the buggy whip - It's not that the modern scopes aren't good, it's just that no one needs the "buggy whip" so they've stopped selling it/adding it as a feature. I used those scopes because the more modern ones I had access to simply didn't even have the Z-Axis feature or they explicitly implemented it as blanking only.

If I didn't need to work on that 8340B then I would never have needed the Z-Axis feature (or at least a Z-Axis feature that was more than just simple blanking) and thus would never have needed an old analog scope.

All I'm saying is that there is one scenario where it made sense to use an analog scope and that scenario is so corner case that it doesn't detract from the underlying point that you were trying to make, which is that modern DSOs are equal to or better than their equivalent period/range analog scopes.

TonyG

Offline guido

  • Regular Contributor
  • *
  • Posts: 207
  • Country: nl
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #71 on: October 03, 2017, 08:37:26 pm »
Don't get me wrong, i analog scopes a lot. Just like the way they work. I have digital scopes, but very old ones. If i need to do anything else then 'scope' business, i take some other tool instead. Like a proper logic analyser, FFT analyser or whatever. If for some reason i would need a modern digital scope, i would just buy it. I might if both my acient digital scopes would go belly up. But i have a lot of bench space and i like fixing up old equipment.

And you need to fix old scopes regularly. Source expensive compents now and then. Or they break beyond repair. It's a hobby :)

I also have the need for an XYZ monitor (scope). I am working on a prehistoric 7612D and that is needed to get a screen (if it would work...). Obviously don't need this digitizer at all, but it is fun to try and get it working. Not working on it often, it usually acts as storage table (it is on a crate, this thing takes the term boat anchor to the max).

On the local sell/buy site here in the Netherlands (not ebay, but ebay owned), it is sometimes possible to get analog scopes for 50 euro's or less. Allthough there are also people that think old stuff is still worth a lot more. Cannot imagine anybody buying those.
« Last Edit: October 03, 2017, 08:39:11 pm by guido »
 

Offline vk6zgo

  • Super Contributor
  • ***
  • Posts: 4846
  • Country: au
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #72 on: October 04, 2017, 07:30:26 am »
I would like to hear your list, even a minority list, where an analog scope is better than a DSO.  Not just equivalent, or sufficient, but better.e

As a prop in a TV program :popcorn:  Slow timebase, mucho intensity and a slow moving dot on the screen.

 8)

Not much call for analog 'scopes or DSOs in TV programs nowadays--------they like a big screen with all sorts of esoteric parameters all over it CSI /NCIS style.

I remember, donkey's years ago, an episode of "Days of Our Lives", where somebody was in Intensive Care, with what was supposed to be a monitor showing their vital signs.

The Set guys had dragged an old Tek 545B in from the Technical area.

Back in the day, D.O.O.L were pretty laid back with their Set designs at any time (so many scenes look like they were done in a furniture showroom), but this was a new low, even for them.
 

Offline vk6zgo

  • Super Contributor
  • ***
  • Posts: 4846
  • Country: au
Re: EEVblog #1022 - Finding A $50 Oscilloscope On Ebay
« Reply #73 on: October 04, 2017, 10:24:51 am »
Don't get me wrong, i analog scopes a lot. Just like the way they work. I have digital scopes, but very old ones. If i need to do anything else then 'scope' business, i take some other tool instead. Like a proper logic analyser, FFT analyser or whatever. If for some reason i would need a modern digital scope, i would just buy it. I might if both my acient digital scopes would go belly up. But i have a lot of bench space and i like fixing up old equipment.

And you need to fix old scopes regularly. Source expensive compents now and then. Or they break beyond repair. It's a hobby :)

I also have the need for an XYZ monitor (scope). I am working on a prehistoric 7612D and that is needed to get a screen (if it would work...). Obviously don't need this digitizer at all, but it is fun to try and get it working. Not working on it often, it usually acts as storage table (it is on a crate, this thing takes the term boat anchor to the max).

On the local sell/buy site here in the Netherlands (not ebay, but ebay owned), it is sometimes possible to get analog scopes for 50 euro's or less. Allthough ther are also people that think old stuff is still worth a lot more. Cannot imagine anybody buying those.

As I said before, I, & others at the time, were "put off" DSOs because the early ones could not look at complex signals like PAL video at field rate, as at,say, 5ms/ div, the sample rate would fall far below the highest frequencies contained in the signal.

The first generation "bombed out"at Line rate!
This would also make it impossible to look at hum on any reasonably high,frequency signals.
I'm not sure how well the ones you have would perform.

I haven't had the opportunity to try this test with any modern 'scopes.

 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf