Analog scope what it's worth? - Page 1
Forum section: electronics / beginners

author: smile
author_rank: Regular Contributor
timestamp: January 30, 2020, 02:12:47 am
content: Analog scope what it's worth? I'm looking for analog scope like 40 MHz Philips etc. Only new, old stock etc.What is the price I would need to pay?Digital is nice, but crazy prices and does not show details like shown in this videoAlso keep in mind I'm from Europe so we don't have ability to buy those cheap scopes from US for like 100USD 100MHZ.Like this onehttps://www.ebay.com/itm/GW-INSTEK-GOS-6112-100MHz-2CH-Oscilloscope/263905036690?epid=11014111173&hash=item3d71f74992:g:zIwAAOSwmrpbhm3U

author: ataradov
author_rank: Super Contributor
timestamp: January 30, 2020, 02:33:18 am
content: Where does this video shows that digital scope "does not show details"?New old stock at this point would actually be worse than a unit that was actually used.In any case what is you use for the scope? Are you going to look at sine and square waves?

author: aix
author_rank: Regular Contributor
timestamp: January 30, 2020, 08:10:20 am
content: Why the requirement for it to be new old stock (as opposed to used)?

author: tggzzz
author_rank: Super Contributor
timestamp: January 30, 2020, 09:30:02 am
content: Quote from: smile on January 30, 2020, 02:12:47 amYou can find the answer to that on fleabay and via google.If you are talking about used, then the rule of thumb is aworkingscope is $£eur1/MHz.

author: smile
author_rank: Regular Contributor
timestamp: January 30, 2020, 10:08:17 am
content: Quote from: ataradov on January 30, 2020, 02:33:18 amWhy? used components dry out faster therfore deteorate. that's professional vcr's and medical equipement have used hours counter etc.Quote from: ataradov on January 30, 2020, 02:33:18 amThe scope would be used to measurePSU Voltage Ripple, various pulse mode supplies like positive negative spikes like desulfator would do. etc.The digital scope seems to filter various details and siply don't show this.But yes measurements on screen is not possible

author: smile
author_rank: Regular Contributor
timestamp: January 30, 2020, 10:09:12 am
content: Quote from: aix on January 30, 2020, 08:10:20 amI certainly would go old stock because, you never know how it was used and how much hours it has been used.

author: aix
author_rank: Regular Contributor
timestamp: January 30, 2020, 10:14:31 am
content: Quote from: smile on January 30, 2020, 10:09:12 amBut why do you care, that's what I don't quite follow. Just personal preference or specific concerns?

author: smile
author_rank: Regular Contributor
timestamp: January 30, 2020, 10:14:59 am
content: Quote from: tggzzz on January 30, 2020, 09:30:02 am"$£eur1/MHz." What? Nobody told that to the sellers? It's a US thingy only then.So why are these scopes like 200Eur for 40Mhz and 150 for 20Mhz ?Go tohttps://www.ebay.dehttps://www.ebay.co.ukand proove me wrong?I know there are nice listings on ebay.com, but given the weight of the item, customs, shipping it will be more then 200Eur for comparale new one on EU listigns.

author: smile
author_rank: Regular Contributor
timestamp: January 30, 2020, 10:15:39 am
content: I don't want to repair something I bought new, and I certainly don't want to go belly up fast.

author: Brumby
author_rank: Unknown
timestamp: January 30, 2020, 12:51:10 pm
content: Quote from: smile on January 30, 2020, 10:14:59 amSellers who have no idea and/or are hoping to hook a sucker - or someone who justhasto have it.As for the $1 per MHz, that even works around Australia (but you may have to wait a while). I picked up a working 20MHz scope with probes and service manual for $22 off eBay.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: January 30, 2020, 01:33:05 pm
content: But the Agilents have a higher $/lb than the others, ISTM.

author: smile
author_rank: Regular Contributor
timestamp: January 30, 2020, 03:54:09 pm
content: Yes it's nice that digital scopes give read out of all parameters like the Hantek DSO5102P can be hacked to 200Mhz wowBut the jaggy looking wave display???

author: ataradov
author_rank: Super Contributor
timestamp: January 30, 2020, 05:25:05 pm
content: Quote from: smile on January 30, 2020, 03:54:09 pm"Jaggy" is how waveform actually looks like. Digital scopes give you more information, not less. So whatever misconceptions you have about digital scopes are just that - misconceptions.Switches, resistors and knobs that were sitting still in an new old stock device would require immediate maintenance before being used.

author: ejeffrey
author_rank: Super Contributor
timestamp: January 30, 2020, 05:54:24 pm
content: Quote from: smile on January 30, 2020, 10:09:12 amHours of use for a oscilloscope is almost entirely meaningless. Hours of use matters for devices that have regular service intervals and known wear processes which do not apply to oscilloscopes. Outside of electrolytic capacitors used at very close to their rating that doesn't really apply to oscilloscopes and electrolytic capacitors can and will still degrade if not in use.Switches and potentiometer condition will depend on how and where the scope was stored, but a used scope may well be better than NOS of the same vintage as regular operation keeps the contacts clean.A NOS device can be DOA just as easily a used scope. If you want something you know is going to work and don't want to repair it you need to buy from a reputable seller who has actually tested the operation and/or provides an operational guarantee.And again, like everyone said, digital scopes show more detail than analog scopes. Analog scopes by their nature hide some types of noise that are actually there. Analog scopes are not bad: they do the basic oscilloscope operations, they have a relatively small and simple set of controls, and they are easy to use and learn. Analog scopes are fine but digital scopes are just better in almost every way. Buy an analog scope if that is what is available or cheap, but unless you are looking for nostalgia, paperweights, or space heaters, prefer digital if you can find it.

author: rstofer
author_rank: Super Contributor
timestamp: January 30, 2020, 06:00:44 pm
content: Unless you want to constrain yourself to audio related projects or very low speed digital, a 40 MHz scope isn't worth much at all. To get a reasonable display of a square wave, in my opinion, you would want to display the 9th harmonic (at least) and 40/9 is just 4.4 MHz. So, in effect, the scope won't well represent a 5 MHz square wave. That's a little slow, I think!I did see a 100 MHz Philips on eBay for $25 but $68 shipping.https://www.ebay.com/itm/Philips-PM3070-100MHz-Digital-Oscilloscope/193317159405I wouldn't expect to get much of a working scope for less than $100 plus shipping and I certainly wouldn't be looking at a scope with less than 100 MHz bandwidth and, if digital, with much less than 1GSps. Equivalent time sampling is voodoo...If you're thinking about digital, where signals are not usually repetitive, the one shot trigger of a DSO makes all the difference in the world. Just imagine the difficulty of visualizing a 1 us pulse that happens 1 time per day (or even per ms) without one shot capture. This feature alone is worth reconsidering analog scopes. About the only thing analog scopes are good for is bandwidth. I have a 350 MHz Tek 485 (about $200 used 15 years ago) but I bought a DS1054Z primarily for decoding but after I discovered the utility of one shot capture, I'm not sure which feature is more important. I know I use one shot more often.In the end, it's just a decision, one of many.

author: BravoV
author_rank: Super Contributor
timestamp: January 30, 2020, 06:15:33 pm
content: Quote from: rstofer on January 30, 2020, 06:00:44 pmPsssttt .. this is the biggest secret recipe that most noobs never get it for 1st time, especially when in confusing moment in choosing analog vs digital scope, and when it times and this will bite really hard, its really-really painful once the noob realized it.To OP, if you thinking real man uses analog scope, let me share you story about analog scope, I own Tektronix 2465B 400Mhz beast, lots of experienced people recognized it probably one of the best analog portable scope ever made on earth.Tell you a dark secret about it, this particular scope, even its never used from factory, still sealed in original plastic wrapping, resides in the original factory box, and never exposed to humidity nor extreme bad temperature, still it will rot by it self. And when you hook up to AC mains to power it up, there is a big chance the power supply part will explode and smoke your room with nasty smell.Btw, if you're so confident, just get one, and btw, in order to fix a scope, 99% you need "another" working scope.

author: rstofer
author_rank: Super Contributor
timestamp: January 30, 2020, 06:33:31 pm
content: Quote from: ejeffrey on January 30, 2020, 05:54:24 pmUnless a trace has been burned into the phosphorous. This is far more of a concern on CROs than DSOs.

author: james_s
author_rank: Super Contributor
timestamp: January 30, 2020, 06:46:30 pm
content: CRTs do have a finite lifespan, the cathodes wear out even if the phosphor is not burned. It's really not a big issue though, it's easy enough to tell if the tube still has a decent amount of life, and a CRO with 10% of its useful life left is a lifetime of use for the typical hobbyist.The ONLY reason to seek out a new old stock analog scope is you are a collector looking for something unique, and IMO the main reason for a hobbyist to look for an analog scope is because old used ones can be had very cheaply and I think everyone should spend a bit of time with one at some point. Once you have a good handle on how a scope works there are very few reasons to use analog anymore though, the trace looks very nice and clean but that's because it is hiding information from you that a digital scope will display. NOS analog scopes are going to be quite rare at this point so if you do manage to find one it will likely cost you more than a brand new Chinese DSO and unless it's something exotic and you have exotic needs, the DSO will be far more capable.You can't base value on what sellers are asking for stuff. There are thousands of items just sitting on ebay collecting dust waiting for a sucker to come along. It has a multiplying effect where someone else finds something they want to sell, looks on ebay to see what people are asking for similar units and then they post it for a similarly optimistic price and pretty soon there are piles of these things sitting there with sky high asking prices. If you want an idea of actual value you have to search for sold items and see what they actually sold for. Of course this doesn't work for "best offer" items, it just says offer accepted.