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Forum Index : Electronics : Value for Money CRO - NOT
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mackoffgrid Guru  Joined: 13/03/2017 Location: AustraliaPosts: 460 |
Ebay - Goldstar Oscilloscope OS-9020 20Mhz,1 Month Warranty They're asking $449 for this !! I seem to remember Goldstar was just a cheap brand sold in the '70s in EA ?? Perusing Ebay for DSO that represents good value for those who don't have one. I found nothing that looked like good value, crowded out by the "cheap junk". Now, the $20 kit is at least absolute entry level - is of little value doing investigative work, but the $40 to $200 region is crowded by non instrument making firms, making poor value hardware. I look forward to the day when we see a "real" dual ch 100Msa 20Meg, portable (or bench) Scope with a real scope front end for <$100. The Owon DS1022 comes close but isn't portable given that its a USB scope. Bang for Buck, the Rigol is a great choice, it's just a bit over the budget of many here. Cheers Andrew |
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Grogster Admin Group  Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
Yes, that is rather rich for an old 20MHz scope, and you are right about the GoldStar brand. Smoke makes things work. When the smoke gets out, it stops! |
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| Solar Mike Guru Joined: 08/02/2015 Location: New ZealandPosts: 1138 |
If you can pickup an older second hand Hitachi like This for a good price, it would be ok. Can run off an internal 12 volt battery pack. I purchased one brand new about 30 years ago when they first came out, still works fine today, batteries long since died. Other than that no repairs needed. Cheers Mike |
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Andrew-L Newbie  Joined: 30/11/2017 Location: AustraliaPosts: 4 |
I bought a Goldstar OS-7020 in late 1988 for $858. That would have been a small fortune back then. The OS-7020 was 2 channel 20MHz. The OS-9020 was also 2 channel 20MHz but included a signal generator so would have been more expensive. cheers, Andrew L Do it once and do it right. |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
I think the very first thing to do BEFORE buying one of these antique oscilloscopes would be to track down an electronic copy of the service and repair manual for the exact model. A great many irritating problems will vanish if all of the small dried out leaky electrolytics are completely replaced on every circuit board. Go over every board with a magnifying glass and re solder any suspicious looking dry joints. All pretty basic stuff, but it can make a world of difference. Cheers, Tony. |
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renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678 |
I can get by for the moment with my little LCD one. This one caught my eye. Not the best on the market but probably a lot smarter to put a bit of extra coin into something new. That will do all I'll ever need from it. Cheers Caveman Mark Off grid eastern Melb |
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| mackoffgrid Guru Joined: 13/03/2017 Location: AustraliaPosts: 460 |
I would agree, paying a little more seems to get a lot more at this end of the DSO market. The biggest peeve with my DSO is the memory, 5000pt / ch. I see that unit has 40k samples, probably overall but much nicer. Cheers Andrew |
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poida Guru Joined: 02/02/2017 Location: AustraliaPosts: 1418 |
heh, 5K samples per channel. <rant enabled. With Boost mode switched in..> The best value investment I made in my electronics engineering venture of soldering, "stand back everyone", bang, whoops and "oh no, not again.." was to get the Rigol 4 channel DSO at about $430 when I bought it. 4 channels. I say it gain, 4 channels. And they are good for 300V RMS, Cat 1 safe. Hacked, it gives 150MHz bandwidth, 12M samples, split 4 ways if you use 3 or more channels, 250M samples/sec per channel when using 3 or more channels. And the trigger options, and the extra memory and the serial decodes. Hacking is easy and still works. Nowadays you get it all for the ticket price and no need to hack. How many times I have wanted to see 3 or 4 signals at once.... We all now groan when I post yet another DSO capture heavy missive on this or that minor detail on PWM behavior. And I bought the DS1054Z AFTER I bought the DS2072 for about $900, again from Rigol. I applied the hack to that, 250MHz bandwidth, 2 channels, 24Mb samples, all the triggers, all the serial decodes work. They are good value and hacking them to enable the options is the way to go. When I see people where ginning around with CRT type oscilloscopes I think "you guyz are missing out on so much more" I own and use a Tektronix 465M CRT CRO, at work. It is used to show the time. I wrote a clock program that makes a vector clock, using an Arduino Due and a real time clock module. First thing in the morning when I get to "work" I switch the CRO on for the time... At home I have a Tektronix 2235 CRT CRO. Bulletprooof. But unused. A DSO is so, so much better for the inverter work I am doing. I had a Tektronix 434 storage CRO, but that was not even usable for one shot events, let alone looking at gate drive details such as I seem to obsess on. It worked, sort of, but when having the 434 and a DSO, the choice is dead easy. 4 channels means: gate drive voltage, and gate drive current, and output voltage from the half bridge, and some trigger source. Which you can examine if needed for correct trigger function. At the same time. All at 250MHz sample rate, good for at least 25MHz details, if not faster.. And the 12M samples means you can record many of the PWM switch events, to examine individually at your leisure. Digital everything means you can save the lot if you want, to disk. Or print. Try that with a Tek 434... You need a camera. And good luck getting the event you want. No scrolling to and from through the captures. I can't convey how educational it is scrolling through captures of switch events of the inverter, number 1...10..20..50..100..200 etc and back again. It gives you a good feel of what the hell is happening. $430 for the most educationally effective tool I have ever purchased... They have gone up now, thanks to the AUS$ losing value vis a vis China's currency. </rant disabled> wronger than a phone book full of wrong phone numbers |
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| mackoffgrid Guru Joined: 13/03/2017 Location: AustraliaPosts: 460 |
I'm in 100% +++ agreement. I used to have a 4ch scope and miss it all the time. The 5k samples is so, so limiting, your 12Msa would be so nice. If it was offered for $430 today I'd jump at it. So my DSO is about 15 years old. Can't remember what I paid for it, probably $399. So, $26.60 per year so far. I spent more than that today for fish and chips (wasn't just for me  )So how long are your Oscilloscopes lasting? What's the annualised cost? Cheers Andrew |
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| poida Guru Joined: 02/02/2017 Location: AustraliaPosts: 1418 |
Annualised cost? Heaps and heaps of $$$. Oh my Dog, I can't count the cost. But then, I just don't care. After paying $12K per year for school fees for one child, paying $4K per year for health insurance which, according to my wife, "we must have!!!!", paying $2.5K in council rates, which seemingly accounts for the 2 bins per week that are picked up, 3 x road rego (my car, my bike, my wife's car), etc. etc. All after tax. It comes down to the equation of approximately 1/2 of who cares anyway multiplied by 3/4 of F*@k-all divided by 3 and 7/8ths of "you are getting shafted, again". These Rigol DSOs have been far, far more value than any pile of books, including - gasp! - Don't let the children see it!!!!- .. .. The Art of Electronics. (The gar-damn Orricarl of Goodness according to all who are E.E. types) If it's a contest to see who can do the most for less, fine. Win all the wins you can win. In a winning way. I do it my way. wronger than a phone book full of wrong phone numbers |
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| mackoffgrid Guru Joined: 13/03/2017 Location: AustraliaPosts: 460 |
That's my point. Good gear is not that expensive and it generally lasts a long time. It annualises to very small amounts, whether its a $300 or a $800 initial purchase. Or a diff probe, multimeter, or current clamp. So just to reinforce the point, for those who ponder new purchases, I'd like to ask others; So how long are your Oscilloscopes lasting? (or other favourite test gear/tools) What's the annualised cost? Cheers Andrew |
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| Mulver Senior Member  Joined: 27/02/2017 Location: AustraliaPosts: 160 |
Hey Poida Would this be suitable as a step down from your four channel unit? with a step down in price? at $380 For someone who wants some detail but is not interested in the amazing detailed analysis that you perform? DS1052E Compared to the DS1054Z at $580 |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
I bought a Tektronix 2465 about a year ago. Analog, cathode ray tube, 200 Mhz, 4 channels, and it was the very last and arguably the very best analog CRO Tektronix ever made. While the display path is all real time analog, it has many of the on screen measurement features and self calibration ability of a digital CRO. I bought that because it was also the last CRO where Tektronix published a full and very comprehensive service manual which is available free on line. So its repairable. Biggest disadvantage of it requires a camera to take a screen shot, which never comes out well for posting on the internet. And Unlike Poida, I find that all four channels get used extremely rarely. Anyhow, I plan fairly soon to get myself a Rigol. Digital storage and the math and measurement capability open up possibilities that are just not possible with an analog CRO. And being able to take and save screen shots for the internet is a big plus too. But for some more obscure things, an analog CRO is still superior. But if you can only afford one oscilloscope, a current model Chinese digital is definitely the best way to go. Cheers, Tony. |
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| poida Guru Joined: 02/02/2017 Location: AustraliaPosts: 1418 |
Mulver, I had a DS1052E, back when they came out. At that time that DSO was about the best value around. Things have changed since then. Rod Elliott uses the DS1052E. He is a very good E.Engineer in my view. Here discusses oscilloscopes and it's an informative read. Even though I bought 2 Rigols, it is clear there are other good value DSOs available now. I bought them when they first appeared. The good AU$ to CN conversion rate back then, and both devices could be fixed so they enable all features via special codes made my choice easy. I would spend some time looking around EEBlog, maybe in the testgear part and see what the general feelings are. I suspect if you asked in that forum "how about the DS1052E?" the answer would be "no mate, get the DS1054Z", followed by a few other reasonable alternatives. Even now, I would find the extra $200 and get a good DSO, rather than the one I budget for. (I took my wife out for dinner with our best friends last Saturday. It cost $160 for us 2, plus I bought 2 bottles of wine. There goes $200 just like that) wronger than a phone book full of wrong phone numbers |
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CaptainBoing Guru Joined: 07/09/2016 Location: United KingdomPosts: 2075 |
LOL, that goldstar scope is exactly the same as mine. served me well over the years but only worth about a tenner today |
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