SH CRO vs DSO (again)

[OriginalMuscian]

I've read through many of the debate threads on buying a SH CRO vs new DSO as a first oscilloscope. The consensus appears to be to get the DSO. However, it's been mentioned that the CRO is better for those who only fix old analog gear (tube amps). But I haven't seen it mentioned why this is. Does the CRO have some sort of advantage over the DSO when fixing vintage analog audio gear?

[madires]

The CRO might support higher input voltages. Besides that it's mostly the vintage factor, I think But I'm not a scope expert.

[vk6zgo]

I've read through many of the debate threads on buying a SH CRO vs new DSO as a first oscilloscope. The consensus appears to be to get the DSO. However, it's been mentioned that the CRO is better for those who only fix old analog gear (tube amps). But I haven't seen it mentioned why this is. Does the CRO have some sort of advantage over the DSO when fixing vintage analog audio gear?

For fault finding,many of the advanced features of modern DSOs are unnecessary.

For instance,if you are looking for a dc voltage of,say,100v,most of the time,you don't really care if it is 98v or 102v,or whatever---it's there,doesn't have huge amounts of ripple,or it has the required signal on it.
You move on to the next test point.

if you need to look at "eye diagrams",or find a "runt pulse" in a pulse train,save screen shots onto your PC,read off voltages,risetimes,etc ,without having to measure them off the screen,or a myriad of other things,something like the Rigol DS1054Z is for you.

DSOs in that class are relatively inexpensive in some markets at around $US400.
Not so cheap in others--$A600 in Oz
OK,you may say,that translates to $US432----but we don't get paid in $US!
Six hundred bucks is still just that!

Most CROs do have quite rugged input circuits,so the chance of damage is less --besides,would you rather cook one channel of a second or third hand $50-$100 CRO or a nice new DSO?

If you go looking for a CRO,ignore the halfwits who try to charge $400+ for an analog 'scope.
You don't need "calibration" for fault finding,so don't pay extra for it.

If you do,in the end,go for a DSO,be prepared to spend enough for a good bench 'scope---not one of the cheap "pretend" things.

[tautech]

If you intend fixing vavle stuff be warned many scopes (CRO AND DSO) have only 300V rated channel inputs and while many with experience can manage this, a moments in-attention and the wrong probe settings can fry the inputs of your scope with an overvoltage event.
Much valve stuff operates below 300v but there is plenty that run on more.

[tggzzz]

For fault finding,many of the advanced features of modern DSOs are unnecessary.

if you need to look at "eye diagrams",or find a "runt pulse" in a pulse train,save screen shots onto your PC,read off voltages,risetimes,etc ,without having to measure them off the screen,or a myriad of other things,something like the Rigol DS1054Z is for you.

Yes indeed. Arguably (endlessly arguably) analogue scopes have less gotchas when browsing around looking at unknown signals to see if they exhibit some completely unexpected behaviour.

I would add startup/shutdown transients as being examples of where a storage scope (either digital or analogue )is highly beneficial.

When looking at valve-level voltages, don't forget to look very carefully at the probes voltage vs frequency rating.

[OriginalMuscian]

So if I were to get either a Rigol 1054Z or a refurbished Tek 2465 (roughly the same price), it seems like I would need to buy additional 600v 10x probes for either scope? Would this be enough to protect me from accidentally connecting either scope to a 500v tube grid?

[vk6zgo]

When valve/tube equipment was more the rule than the exception,blown up 'scope front ends or probes were very rare,so the risk is a bit overstated.
And it wasn't that they had tube front ends--Solid state front ends on 'scopes were common throughout much of the later tube era.

Voltage ratinga aren't "after this point your 'scope or probe will vapourise"--they are,instead, very conservative,so that you are unlikely to suffer any disastrous consequences around most tube equipment.
It is always best to use X10 probes around tube circuitry,just in case,though.

The old Tektronix probes were not significantly derated until quite high frequencies,& I suspect modern ones are the same.
The standard Rigol ones are most probably similar,but some of the after market "El Cheapo" ones start to derate above about 10kHz.

If you blow up your X10 probe,it doesn't mean that you will damage your 'scope,too.
Usually it is more a matter of the probe insulation breaking down,& offering an alternative path between the probe hook & common,rather than a breakdown of the series resistance in the probe.

Much as it pains me to say so,as an analog person,but if the Rigol is the same price as the 2465,you should go with the DS1054Z.
You should,however,be able to pick up a good,earlier Tek or HP CRO with  comparable performance to the 2465,for a lot less than the price you are contemplating.

[OriginalMuscian]

The 2465 has had the caps replaced, the IC heatsink mod done, and is calibrated. But it's sounding like the old analog scopes are getting near extinction. I imagine in another 8 years they'll be considered as a great museum piece, unnecessarily large and heavy, and not nearly as useful as modern equipment (albeit with some specialized advantages that a handful of geniuses still find necessary). Then again, by then, the Rigol 1054Z could also easily be considered outdated legacy equipment with minimal functionality.

So that brings up the scenario of getting an analog scope and learning on it for the next 5 years before making room for the latest and greatest low-cost DSO wonder. A Tek 465 in good working condition can be found for about $200. I'm not sure if these had issues that typically need to be addressed. Are these old enough where the electrolytic caps have typically already been replaced? Or can a scope of 80's vintage still be working well with the original capacitors?

Also, is it true that many of the 22xx series were made in China and are considered lessor quality scopes?

[tggzzz]

So if I were to get either a Rigol 1054Z or a refurbished Tek 2465 (roughly the same price), it seems like I would need to buy additional 600v 10x probes for either scope? Would this be enough to protect me from accidentally connecting either scope to a 500v tube grid?

You will benefit from the relevant references here: https://entertaininghacks.wordpress.com/library-2/scope-probe-reference-material/

[Gyro]

If your main aim is to use the scope for repairing analogue gear and valve stuff then you don't need anything near 300MHz, 4 Channels or fancy on-screen readouts. I think the Tek 2465 is serious overkill. For an analogue scope these days you want reliability... highest bandwidth and complexity will give you the opposite!

I'd be looking for a decent brand 2 channel in the 100MHz range (probably a bit lower for the right price) and skip the readouts, you don't need them. That should give you much more reliable scope (certainly not full of heatsinked chips!) which will serve you well until your requirements change.

When / if your projects need a DSO then buy one then, the longer you leave it the better you will get for the same money. They're not designed for long life anyway. There's no point in trying to spend the same money as a new Rigol 1054Z for an analogue scope now.

To answer your other question, yes there are many (probably the vast majority of) '80s analogue scopes working today with their original caps. Caps in analogue scopes are used on analogue regulated supply rails (probably avoid any with a SMPS), it's a different situation to DSOs (and the likes of the Tek2465) where you have highly stressed small low-esr caps on the SMPS, tiny smd electrolytics that leak on logic supplies etc.

Spend as little money as you need to buy a working decent professional scope that meets your needs and that you have a very good chance of maintaining yourself until / unless your requirements change.

Edit: At 100MHz or a bit below you should be able to find a scope that uses discretes in the Y amps rather than custom ICs which might ease your worries a bit. Check the service manuals when choosing.

Edit 2: Look for one with a decent low noise minimum sensitivity setting too, eg 1 or 2 mV/div (something else that doesn't fit with high bandwidth). That will be useful if you start using 100:1 probes on valve gear.

[grumpydoc]

If your main aim is to use the scope for repairing analogue gear and valve stuff then you don't need anything near 300MHz, 4 Channels or fancy on-screen readouts. I think the Tek 2465 is serious overkill. For an analogue scope these days you want reliability... highest bandwidth and complexity will give you the opposite!

+1, to a point

The 2465 is a nice 'scope - but probably not the best choice for a beginner.

I really like the Hitachi V1065 https://www.eevblog.com/forum/testgear/teardown-hitachi-v1065/ and related 'scopes they are fairly lightweight, pretty easy to use and work on and have an absolutely pin sharp trace. There are a couple of unobtainable components but for the most part they are pretty standard.

Another nice analogue 'scope to use is the Tek 2245 and the other 'scopes in that series (the 2247 and 2252) - they do have some Tek magic components but are, again, quite nice 'scopes to actually have on the bench and use.

'Scopes are a bit like cameras - the best one is the one you have in your hand (or, rather, on the bench). Unless you want to go prodding multi-gigahertz singals on modern motherboards something in the 100MHz region will be fine.

I'm sure I'd like a modern DSO if I had one - my DSO is an ancient LeCroy 9354 which I use if I do want to capture a lengthy trace and go over it afterwards but otherwise I tend to use an analogue 'scope (well actually one of the Phillips Combiscopes which I also quite like but they probably aren't an especially good choice for a beginner either).

[madires]

An used Hameg CRO would be also a good choice. Reliable and standard parts.

[grumpydoc]

An used Hameg CRO would be also a good choice. Reliable and standard parts.

Yes, another good choice.

One thing that I would say about analogue 'scopes is a) stick with a known reliable make (several of which have been discussed) and b) make sure you can get a service manual.

[Ian.M]

If at all possible, you want a delay timebase + trigger view.   The delay timebase lets you zoom in on stuff, and trigger view effectively gives you a third channel when trigger is set to EXT, albeit with very poor choice of input attenuation.   However on most scopes, the trigger view mode is good enough to get a SPI /CS signal on screen so you can use the other two channels for clock and data. and count your way from the falling /CS edge to the bit you want to check.

Of course that's trivial on a 4 channel DSO, but if all you've got is a $100 CRO, you learn to make the best of it.   

If you are going used CRO shopping in person, it may be worth taking something pocket sized that will make some known waveforms with you.  Sure, you can look at the scope's own calibrator output, but that wont show up any vertical nonlinearity.  You need a triangle wave generator for that.

[vk6zgo]

The 2465 has had the caps replaced, the IC heatsink mod done, and is calibrated. But it's sounding like the old analog scopes are getting near extinction. I imagine in another 8 years they'll be considered as a great museum piece, unnecessarily large and heavy, and not nearly as useful as modern equipment (albeit with some specialized advantages that a handful of geniuses still find necessary). Then again, by then, the Rigol 1054Z could also easily be considered outdated legacy equipment with minimal functionality.

So that brings up the scenario of getting an analog scope and learning on it for the next 5 years before making room for the latest and greatest low-cost DSO wonder. A Tek 465 in good working condition can be found for about $200. I'm not sure if these had issues that typically need to be addressed. Are these old enough where the electrolytic caps have typically already been replaced? Or can a scope of 80's vintage still be working well with the original capacitors?

Also, is it true that many of the 22xx series were made in China and are considered lessor quality scopes?

You didn't read this comment in my first posting,did you?
"If you go looking for a CRO,ignore the halfwits who try to charge $400+ for an analog 'scope.
You don't need "calibration" for fault finding,so don't pay extra for it."

On the "will it be useless in eight years?" question:-
Oscilloscopes aren't like smartphones & the like,which can be obsolete in eight years.
Waveforms will still be here,just as they have in the past.

In eight years time,an analog 'scope will still be able to do the things it does now,& the DS1054Z will still be the very capable device it is now.
It all depends if you want an oscilloscope to look at signals,or a magic box which tells you all the answers!

[dom0]

An used Hameg CRO would be also a good choice. Reliable and standard parts.

And usually more expensive in Germany than Tektronix in terms of Bandwidth-Channel-Product per Money-Unit (MHz/EUR), even for basic models with single TB.

[Gyro]

I really like the Hitachi V1065 https://www.eevblog.com/forum/testgear/teardown-hitachi-v1065/ and related 'scopes they are fairly lightweight, pretty easy to use and work on and have an absolutely pin sharp trace.

Another good point... lower bandwidth 'conventional' CRTs do tend to have better trace sharpness. Distributed Y plates, mesh PDAs, microchannel, etc on the highest spec CRTs are great for writing speed and bandwidth but they don't do such good things for ultimate sharpness. Not a universal rule but often seems to be the case.

On the "will it be useless in eight years?" question:-
Oscilloscopes aren't like smartphones & the like,which can be obsolete in eight years.
Waveforms will still be here,just as they have in the past.

In eight years time,an analog 'scope will still be able to do the things it does now,& the DS1054Z will still be the very capable device it is now.

No argument there, they should both be capable of what their spec is today - at eight years old it really comes down to your ability to fix what goes wrong, quality of switches and knobs, contacts, thermally induced component aging etc.

[dom0]

I really like the Hitachi V1065 https://www.eevblog.com/forum/testgear/teardown-hitachi-v1065/ and related 'scopes they are fairly lightweight, pretty easy to use and work on and have an absolutely pin sharp trace.

Another good point... lower bandwidth 'conventional' CRTs do tend to have better trace sharpness. Distributed Y plates, mesh PDAs, microchannel, etc on the highest spec CRTs are great for writing speed and bandwidth but they don't do such good things for ultimate sharpness. Not a universal rule but often seems to be the case.

Analog storage scopes have probably the by far worst image quality of all analog scopes. One can clearly see the storage meshes in the beam, even in non-storage operation.

(And my particular 7623 also has quite poor astigmatism and geometry even at optimal adjustment. But this might be a flaw of the particular tube and not 7623s in general)

[Gyro]

Yes absolutely, I'd never go for an analogue storage these days. The mesh I was talking about though is the domed mesh that's used in conjunction with the PDA spiral coating in the cone to make the acceleration more uniform. That's there in non-storage fast tubes too (you can see it if you de-focus the spot all the way).

[Zero999]

Most CROs do have quite rugged input circuits,so the chance of damage is less --besides,would you rather cook one channel of a second or third hand $50-$100 CRO or a nice new DSO?

Another advantage of old analogue oscilloscopes is, they tend to be much easier to repair, than modern digital 'scopes, which have mostly SMT parts and no detailed schematics in service manual, if you're lucky enough to be able to get one.

[dom0]

Even a 500 MHz 7904 is practically completely THT :-)

[vk6zgo]

I really like the Hitachi V1065 https://www.eevblog.com/forum/testgear/teardown-hitachi-v1065/ and related 'scopes they are fairly lightweight, pretty easy to use and work on and have an absolutely pin sharp trace.

Another good point... lower bandwidth 'conventional' CRTs do tend to have better trace sharpness. Distributed Y plates, mesh PDAs, microchannel, etc on the highest spec CRTs are great for writing speed and bandwidth but they don't do such good things for ultimate sharpness. Not a universal rule but often seems to be the case.

On the "will it be useless in eight years?" question:-
Oscilloscopes aren't like smartphones & the like,which can be obsolete in eight years.
Waveforms will still be here,just as they have in the past.

In eight years time,an analog 'scope will still be able to do the things it does now,& the DS1054Z will still be the very capable device it is now.

No argument there, they should both be capable of what their spec is today - at eight years old it really comes down to your ability to fix what goes wrong, quality of switches and knobs, contacts, thermally induced component aging etc.

An Oscilloscope used in a commercial workshop,where it is left switched on all day,"pushed around from pillar to post",used by multiple people,etc,will accrue more operating hours,bumps,scars,etc & will be more likely to fail than one in the much more benign environment of a "home lab".
An eight year old 'scope is probably still thought of as "the new one",in many workshops.

With the old analog beasts,another eight years on top of an existing "thirty plus" probably won't have any great effect,again considering the much softer life in a home lab.

[OriginalMuscian]

I'd like to thank everyone for their thoughtful replies. I'm thinking I'm better off with the 1054Z. It will do everything I need with much room left to grow in to. It also fits better on my bench.

I have also acquired a free HP 130c. It has been stored in a humid garage for two years and worked fine when first stored. It powers up and displays a dot, but it doesn't properly display a trace or vertical deflection when voltage is input. I've looked inside, and it looks pretty clean, other than having a few tubes on daughterboards that were double-side taped to the main boards. The tape has since degraded, and the daughterboards are resting loose. But I suspect the problems with the scope operation lie elsewhere.

This scope has banana plugs for the probe inputs. Can I use a regular BNC probe with some kind of adapter? For instance this one:

http://www.ebay.com/itm/BNC-female-jack-to-two-dual-Banana-male-plug-RF-adapter-connector-/320847592228

Or this:

http://www.ebay.com/itm/BNC-Q9-To-Banana-Plug-Connector-Oscilloscope-Test-Probe-Leads-100CM-DUS-/361432101810?hash=item54270833b2:g:3cYAAOSwkZhWTTIq


I'll probably never acquire the necessary skill to fix this scope, but it seems worthwhile to try.

[MrSlack]

Look for some normal cheap 1x-10x probes with hooks on ebay; they're easier to deal with than banana plugs and have less side effects.

[OriginalMuscian]

I woke up this morning in a crazy mood. I think I might have contracted the oscilloscope madness I've seen others on this forum attest to. Within 5 minutes of opening my eyes, I had already logged onto my laptop and bought a 465b off ebay.

It looks like I'll be taking a rain check on the Rigol.

http://www.ebay.com/itm/Tektronix-465B-Analog-Oscilloscope-/172022076060?nma=true&si=xPAUfDac6UrSfThOSDH0p%252F3gQLk%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

[Ian.M]

A 465B in good working order is a pretty nice analog scope.   2 channels + Ext trig view (for which you *WILL* need either an external attenuator or a switchable x1/x10 probe).  As I said earlier, that's good enough if you get into digital stuff, e.g Arduinos and slower MCUs.  For valve gear, its all down to how good your probes are.   Cheap and nasty probes may not have a suitable voltage rating for working on high powered stuff.  Also, its max input range is 50V/div , which, with 8 divs vertically is +/-200V, so if you are monitoring an output valve plate and you accidentally switch to x1, its probably game over.
 
I would suggest a new pair of budget x1/x10 switchible probes, and a used named brand fixed x10 probe with a higher voltage rating.  Up to 600V, fixed probes are fairly easy to find.  1000V probes are more expensive and *much* rarer - you'll probably pay as much as you did for the scope for such a probe new.  For a class B valve output stage you need a probe with a voltage rating of 2.5 times the HT voltage to allow for the CT primary to swing above the HT rail by as far as its other end is being driven down + an adequate safety margin.

[OriginalMuscian]

Ian:

If I understand you post, then a 600v probe will safely handle a HT voltage of about 240v. To go higher, I would need a 1000v probe.

I found some fixed x10 Hameg probes that are listed as:

Maximum AC Input Voltage: 40 V RMS
Working Voltage: 600 VDC including AC

The max AC Input Voltage rating is confusing to me. What does it mean?

Thanks!

[Ian.M]

Hmm....  Its confusing me too!   Got a link and a specific probe model number?

[dom0]

They just don't give the maximum AC at 50 Hz or so but at a few MHz, or even rated frequency. All passive probes derate maximum level by frequency. No exceptions.

[OriginalMuscian]

I ended up buying two cheap 1x/10x probes and a 100x. The Hameg probes were interesting but confusing. Here's the link to the auction:

http://www.ebay.com/itm/Two-100MHz-X10-Oscilloscope-Probes-/151913803442?hash=item235ec4aeb2:g:rh8AAOSwYHxWJDj~

[Ian.M]

The issue for those Hameg x10 probes the auction identified as "ETS1011" is:
What frequency do you have to start derating them above, and what's the derating curve?

Googling that part number, with x10 probe only finds that auction.   Without a datasheet,.I certainly wouldn't trust them above a couple of hundred volts so you probably did well to avoid them.

[janoc]

As I said earlier, that's good enough if you get into digital stuff, e.g Arduinos and slower MCUs. 

For that the new Rigol would have been a lot better - single shot capture, built-in serial decoding and 4 channel logic analyzer are a huge boon compared to counting and decoding bits manually on an ancient analog scope.

Nothing against the Tek, but unless it was less than $100-$150 delivered, it is not a good value today.

[Ian.M]

Yes. Using a 100MHz 2 channel analog scope with trigger view and delay timebase for digital work is a 'hair shirt' experience, but good for the soul.  If you only have a 50MHz  scope with a plain timebase and no trigger view, its like combining an augury with ritual self-flagellation.

[MrSlack]

I used a broken Philips PM3217 and home made probes that cost me nothing that the triggering was knackered on for about 10 years. Finally gave up in 2009. You can still get a lot of mileage out of junk, especially if it has a delay function

[tggzzz]

Yes. Using a 100MHz 2 channel analog scope with trigger view and delay timebase for digital work is a 'hair shirt' experience, but good for the soul.  If you only have a 50MHz  scope with a plain timebase and no trigger view, its like combining an augury with ritual self-flagellation.

Depends on what you are doing.

If you are troubleshooting signal integrity then 100MHz (preferably higher) is mandatory, and if the signal is repetitive then you probably don't need a storage function.

If you are troubleshooting mechatronics type signals and the signal can be made repetitive, then 20MHz is probably sufficient.

If you want protocol decodes at any speeds, then use a logic analyser or printf at either or both ends Get the signal integrity right, then don't use a separate tool that might interprets analogue signal differently to the real receiver.

[OriginalMuscian]

Nothing against the Tek, but unless it was less than $100-$150 delivered, it is not a good value today.

It was $157 delivered (no probes included) and is purported to work well. I will be using it (infrequently) to fix and maintain audio tube gear. My guitar amps are older than the scope, so there's some weird nostalgic value going on here for me. If I manage to come to my senses a few years from now, I'll donate the museum piece and get a DSO.

On another note, having shopped on eBay recently, the number of broken "Buy it Now" scopes listed > $150 shipped is seriously appalling.

[OriginalMuscian]

I received the scope today via UPS. US mail tracking shows both sets of probes were delivered on Saturday. However, I didn't get the probes. Either the busy mailman put them in the wrong box, or I was hit by Christmas-time rural mailbox thieves. I suspect the latter, so I ordered new probes and will keep a closer eye on my mailbox this time around.

The scope was packed surrounded by newspaper. For an item this heavy and fragile, I personally would only use large bubble wrap. Sure enough, I removed the scope from the box and found one of the rear feet had been broken off during shipment and was laying in the bottom of the box. 

I plugged the scope in and turned it on, and a horrible noise emanated from the fan area. It sounded like either the fan was rubbing or the bearings were going out. Fortunately, it turned out to be the fan rubbing on the grill (probably from the rough trip across the US). So I fixed it and then hooked wires between the BNC connectors and a signal generator in order to test the function of the scope. Nearest I can tell, all buttons, knobs, sweeps, lights, switches, delays, etc. appear to be working fine, and the scope is in very nice condition.

The only thing that appears odd or off about the scope is the test loop on the front of the scope only measures 157mv (it's rated at 300mv) with my Fluke DVM (verified with my cheap DVM). I notice my HP scope also measures a low calibration output voltage. Is this common with older scopes. Is it a sign that the scope is out of calibration?

Thanks for your input!

[alsetalokin4017]

The probe calibrator will put out a square wave, and the voltage spec for it is the peak voltage. DMMs do an excellent job of _averaging_ the voltage of square wave signals, as your testing seems to demonstrate.

Congratulations on your new-old scope!

[Brumby]

The only thing that appears odd or off about the scope is the test loop on the front of the scope only measures 157mv (it's rated at 300mv) with my Fluke DVM (verified with my cheap DVM).

Put the signal onto one of the inputs of your scope and you should see a 300mV peak to peak square wave.


Edit: Snap!

[tautech]

The only thing that appears odd or off about the scope is the test loop on the front of the scope only measures 157mv (it's rated at 300mv) with my Fluke DVM (verified with my cheap DVM). I notice my HP scope also measures a low calibration output voltage. Is this common with older scopes. Is it a sign that the scope is out of calibration?

No.

Many old scopes the Cal output is adjustable, check the SM.
Feed the Cal output into your HP to check it's REAL characteristics meet spec.

[OriginalMuscian]

I measured the peak to peak voltage, and it came out to exactly 300mv. So I hooked up a signal from an old HP 200CD Audio Signal Generator, and the scope sign wave closely matches the amplitude on the 200CD dial.



This scope is really super fun. I've already managed to fix a problem with a 1972 Fender Twin Reverb guitar amplifier that's been sitting in the corner for three years. Next, I'm going to measure the output of my 5500W generator in order to determine if the wave shape suits running household electronic equipment during a power outage.

OK, I know I'm grasping at straws here compared to you guys, but none-the-less, I'm really excited to have the scope.

Thanks for all of your help!

[Brumby]

Having an oscilloscope is really exciting.  You can SEE things that you never knew were there.

I remember when I picked up my first (and only) oscilloscope - a brand new Hitachi V-152B - from Dick Smith.  A big day indeed.

[tggzzz]

Next, I'm going to measure the output of my 5500W generator in order to determine if the wave shape suits running household electronic equipment during a power outage.

Unless you know what you are doing, you stand a good chance of destroying the scope, the scope probes, or yourself.

You would be wise to read, learn and inwardly digest the safety references in the "Praxis" subsection of https://entertaininghacks.wordpress.com/library-2/scope-probe-reference-material/

[Ian.M]

+1.  I wouldn't even attempt that without a CAT III differential probe rated 600V RMS or better.   It would be possible with a x100 probe with an adequate voltage rating, but if the generator neutral is grounded in the wrong place or you make any mistake, you will have a very bad day, or worse.

[OriginalMuscian]

Thanks for the warning.  I'll have to figure out the grounding issue, as I notice my generator has a couple of different ways it can be grounded.

My probes were delivered to the wrong address, and somebody finally returned them to my mail box. So I have probes now! Here's my high voltage probe:

http://www.ebay.com/itm/121756895609

And here's a picture of my new scope hooked up to my 1x probes:

[oldway]

To measure the waveform of your generator, use a transformer with insulated low voltage secundary (12V for example)...this is far more secure and there is no problem of grounding anymore.

[Ian.M]

That's a no-name, probably Chinese probe.  Before trusting it for high voltage work, inspect it carefully, load the scope end with a BNC chassis socket with  1Meg || 30pF across it (*NOT* a scope or other delicate , ground the shell and do a thorough high voltage insulation test, with the test voltage applied to the probe tip, paying particular attention to testing for flashover everywhere around the probe body from the Earth lead back to the cable.

It should read as 100Meg leakage resistance, and as long as it remains in good condition and is retested regularly, I'd trust it up to the insulation test voltage, but not for CAT II or higher work.  i.e. nothing on the mains side of any equipment fuse.

OTOH if it can be traced to a western manufacturer, you can probably trust its ratings.   Remember, improving paper 'specifications' doesn't cost anything in China unless it directly harms a party official or their family, or they get caught out and loose a big sale.

[tautech]

That's a no-name, probably Chinese probe...... 

Hardly.

It's from the YPiIONEER range of which the P6000 range is the most common.
Specs:
http://www.ypioneer.com/htmlmodel/cpxx/12564336.html

[Ian.M]

Well I hope I can be pardoned for making that mistake as I found what appeared to be the same probe listed under three different brand names, shipping from China., and you've just added a fourth.    That makes it very hard to tell if its a genuine OEM item produced for any of the brand names, from a ghost shift run or is from 'gongkai' design sharing. 

What should OriginalMuscian check to be sure he hasn't got a cheap and possibly dangerous knock-off?

[tautech]

Well I hope I can be pardoned for making that mistake as I found what appeared to be the same probe listed under three different brand names, shipping from China., and you've just added a fourth.    That makes it very hard to tell if its a genuine OEM item produced for any of the brand names, from a ghost shift run or is from 'gongkai' design sharing. 

What should OriginalMuscian check to be sure he hasn't got a cheap and possibly dangerous knock-off?

Pardoned, of course, you were not aware of YPIONEER, most aren't.
It is not a widely known name, however the many million P6100 probes they have made are.
I can assure you the brand name is OEM and re-branded or sold as the OEM probe for many Asian equipment suppliers. I'll add that as most resellers of any product attempt to keep their suppliers secret, it is not at all surprising to find the same product available from several sources.


The probes in question are another thing, they are not your "run of the mill" units, 100:1, 2kV probes rarely are.
That the manufacturer lists extensive specs should offer some confidence.

Copies of their probes might be another thing    as most probes from many equipment supplies never state the original probe manufacturer, so yes how would one know?
As with much Asian supply one can only search out those suppliers with good ratings.

FYI
I have sold dozens of YPIONEER P6100 probes without problem.
It's a brand I'm confident with.

[dom0]

To measure the waveform of your generator, use a transformer with insulated low voltage secundary (12V for example)...this is far more secure and there is no problem of grounding anymore.

Don't use a too small transformer. Something with a dozen VA or more. Load it lightly (a few percent of rated load), ohmic.