EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: JCK on July 31, 2015, 05:01:00 am
-
Just got my Rigol 2072a scope. So far I'm pretty impressed with the overall quality and versatility of the instrument :-+. But I'm not too impressed with the quality of the 300MHz probes :--, they seem kind of cheap to me, especially the witches hat? So I'm wondering what everyone else thinks about them and how the hold up over time? Also I noticed replacements are about $44.00, not to bad compared to TEK or Agilent but not cheap for a hobbyist either, so I'm a little concerned. Thoughts anyone?
John
-
Exactly the same problem exists with the probes that are shipped with the 1054z.
-
I like the probes that come with the 2000 series, especially the fact that they are 10x fixed with no switches. I have had no issues with them and don't expect any.
What don't you like about them? This is a Rigol scope and Rigol probes, not top of the line Agilent gear that costs $10k per probe.
-
I just think the probes seem lesser quality than the scope itself. I hate the insulating sleeve on the ground clip, really stiff an inflexible. That said, I haven't had any real problems with them, and they seem to work OK. Mostly just my first gut feel impressions.
John
-
I bought an extra probe (Testec), which I use as my main. I might buy a second one as well.
Rigol probes are ok to start with, but the hook and ground clip are not very convenient to use.
-
markce, those Testec probes look nice. I'm currently searching for a pair of 250/300 MHz 10x probes as mine have gone missing in a move!
-
dkozel, I bought the Testec HF212 (Conrad, Eur 45 last year). This is a 10x (fixed), 300MHz probe
with two point adjustment, nice feel and handling.
-
Thanks markce. I bought a set of two Testec MF-312 probes last night for 41 gbp, 57 eur, from Farnell. They have the advantage of being 1/10x switchable and reasonably affordable.
-
Arg. And they arrived (fast!) with a bent tip... The set includes a replacement tip, but I deplore the idea of starting with a brand new item that might have internal damage to the tip socket.
(http://s15.postimg.org/3k632xb53/testec_bent.jpg) (http://postimg.org/image/3k632xb53/)
-
A bent tip, so it's not new...
Tip bending happened to me also, but at least I myself was to blame. The tips are rather soft, and if put in a calibration
hole like on the Tektronix 22xx they bent, but are also easily straightened.
Personally I don't want 1x/10x switchable probes. They always tend to be in the wrong position for me :-//
-
The bending occurred during shipping. They should be brand new.
Given that at the moment this is my only set of probes the flexibility was worth the fuss of checking the switch state. At least an off by 10x error is very easy to notice. If I still had the original Rigol ones then I'd probably have gone for a single HF212. But the DS2000 is also a limiting factor, so the system bandwidth wouldn't be increased much by adding 50MHz to the probe. :-//
-
I've a dedicated 1x Tek probe, and prefer 10x fixed for HF probes. There is only one switched probe that I liked,
a 88100 100MHz probe from ages ago, which has a true horizontal switchover. I dislike the Rigol alike slide switch.
I also bought the HF212 for its double compensation adjustment. It is more expensive, but for a new probe still good value for money and
nicely fits in my range.
In general, as a replacement for the original Rigol 2000 probes, I think the Testec MF312's are very good value.
-
Farnell has great service! I emailed them over the weekend and by 10am Monday morning they'd dispatched a replacement set and scheduled a UPS pickup of the damaged ones from my house for today. I asked them to have the pickup done from work and they came back 5 minutes later letting me know they'd changed the locations. The replacements arrived this afternoon in the most disproportionate box I've seen yet (But absolutely damage proof!) and the pickup went smoothly. :-+
Now to get back to peeking at my circuits!
-
The PMK PMM probe looks nice, but it's 3x the price of a Testec HF212 ...
-
Probemaster is another good one.
-
Hmm, Rigol RP3300A is $44.00, Probemaster 4900 is $73.00. Is Probemaster $29.00 better :-//
-
My DS2072 came with Switched 1x - 10x probes, maybe this changed with the A model?
Can't fault my probes at all.
I like the probes that come with the 2000 series, especially the fact that they are 10x fixed with no switches. I have had no issues with them and don't expect any.
What don't you like about them? This is a Rigol scope and Rigol probes, not top of the line Agilent gear that costs $10k per probe.
-
DS2072 had RP3300 switchable probes? My DS2072A came with RP3300A fixed 10x probes.
It has a lower probe capacitance (13pF), which I prefer. I almost never need 1x, so can live with changing probes for this.
-
Just checked the probe bags and they are RP3300.
DS2072 had RP3300 switchable probes? My DS2072A came with RP3300A fixed 10x probes.
It has a lower probe capacitance (13pF), which I prefer. I almost never need 1x, so can live with changing probes for this.
-
The probes on my DS2072 are rated at 400V. Was measuring a 450V pulse with a 1uS rise time and blew it up. Note to self: probe voltage rating is also frequency dependent. After that I got a pair of dirt cheap ebay x1/x10 probes and also a pair of 2kV x100 probes. On the rare occasion I need real bandwidth I use the good probe. Day to day hack stuff the cheap probes get used.
-
DS2072 had RP3300 switchable probes? My DS2072A came with RP3300A fixed 10x probes.
It has a lower probe capacitance (13pF), which I prefer. I almost never need 1x, so can live with changing probes for this.
Ditto!
-
450v on 400v probes in to a 300Vrms Scope :palm:
The probes on my DS2072 are rated at 400V. Was measuring a 450V pulse with a 1uS rise time and blew it up. Note to self: probe voltage rating is also frequency dependent. After that I got a pair of dirt cheap ebay x1/x10 probes and also a pair of 2kV x100 probes. On the rare occasion I need real bandwidth I use the good probe. Day to day hack stuff the cheap probes get used.
-
The probes on my DS2072 are rated at 400V. Was measuring a 450V pulse with a 1uS rise time and blew it up. Note to self: probe voltage rating is also frequency dependent.
Lesson learned. :-+
Good advice would be use the 100:1 probes you bought for all work over ~200V.
You're also lucky you didn't fry the input stage in your DSO, remember Rigol's inputs are ony rated to 300V.
-
Just got my Rigol 2072a scope. So far I'm pretty impressed with the overall quality and versatility of the instrument :-+. But I'm not too impressed with the quality of the 300MHz probes :--, they seem kind of cheap to me, especially the witches hat? So I'm wondering what everyone else thinks about them and how the hold up over time? Also I noticed replacements are about $44.00, not to bad compared to TEK or Agilent but not cheap for a hobbyist either, so I'm a little concerned. Thoughts anyone?
John
The probes that come with the Rigol 2072A are the RP3300A, these are rated at 350 MHz. According to Dave (EEVblog #707), you calculate the system bandwidth using the following equation:
1/sqrt((1/scope bandwidth)^2+(1/probe bandwidth)^2) = system bandwidth
The 2072A has a bandwidth rating at 70 MHz, thus the equation looks like this:
1/sqrt((1/70 MHz)^2+(1/350 MHz)^2) = 68.64 MHz
However, if you were to hack your 2072A to 300 MHz the equation changes to:
1/sqrt((1/300 MHz)^2+(1/350 MHz)^2) = 227.78 MHz
-
450v on 400v probes in to a 300Vrms Scope :palm:
The probes on my DS2072 are rated at 400V. Was measuring a 450V pulse with a 1uS rise time and blew it up. Note to self: probe voltage rating is also frequency dependent. After that I got a pair of dirt cheap ebay x1/x10 probes and also a pair of 2kV x100 probes. On the rare occasion I need real bandwidth I use the good probe. Day to day hack stuff the cheap probes get used.
Well,if he was using a x10 probe,all the 'scope will see is 45volts.
Besides,300v rms is around 424v peak,so he almost made it,as far as the 'scope was concerned,even with a x1 probe.
All the old Tek equipment was very conservatively rated,so you could over step the mark a bit---it was usually rated a bit higher,anyway, than modern stuff.
x100 probes were unheard of in the old tube days,when "400-odd" volts wasn't at all unusual
-
But wait--there's more!
The derating curves on some of the probes seem to be "a trap for old players"!
I couldn't really see how the derating with frequency would be a problem, with a 1uS risetime,as the old Tek,HP,Siemens,etc probes showed no discernible max voltage derating until well above 1MHz.
See fig (7) in this link:
http://assets.tequipment.net/assets/1/26/Documents/P6105A_Instructions.pdf. (http://assets.tequipment.net/assets/1/26/Documents/P6105A_Instructions.pdf.)
On looking back at some earlier threads,it appears that Rigol probes start to derate in the 10s of kHz.
https://www.eevblog.com/forum/beginners/scope-maximum-input-voltage-(dc-an-ac)/ (https://www.eevblog.com/forum/beginners/scope-maximum-input-voltage-(dc-an-ac)/)
Being used to the Tek probes,I could have easily blown up a cheapie Jaycar probe,which probably share the same,or similar curve.
Probably the plugin in the 7613 would just "grunt" & get in with its life,but it is a sobering thought.
I have blown the end off a probe in the grid circuit of a MF Broadcast PA stage,many moons ago,in the dark reaches of the night when the brain doesn't work well. ;D
Didn't bother the 465---,bit hard explaining it to the Boss,though!
-
Probe use should NEVER assume frequency derating OR max probe voltages, to do so puts yourself and your scope at risk.
That funny graph on the bit of paper in the probe packet is to be kept and referred to regularly, especially when probing at elevated voltages and frequencies. It matters not what ANY other manufacturers ratings might be, the only thing that matters are the specs for the probe you are using. Significant variation across various 10:1 probe brands lead me to get cheap100:1 probes for safety and sanity.
-
x100 probes were unheard of in the old tube days,when "400-odd" volts wasn't at all unusual
Or the analogue computers with patch-panels. It was drummed into you, in two ways, that the "wrong" end of the patch cord had 100VDC on it!
-
Probe use should NEVER assume frequency derating OR max probe voltages, to do so puts yourself and your scope at risk.
That funny graph on the bit of paper in the probe packet is to be kept and referred to regularly, especially when probing at elevated voltages and frequencies. It matters not what ANY other manufacturers ratings might be, the only thing that matters are the specs for the probe you are using. Significant variation across various 10:1 probe brands lead me to get cheap100:1 probes for safety and sanity.
Or,only use old Tektronix 10:1 probes!
I like the ones that were used on 545B's---"built like a brick dunny",they've already lasted half a century. ;D
Not that big on frequency response,but good enough for a lot of work!
Strangely,the only time I have found it really necessary to use a 100:1 probe was for the high impedance,rather than the voltage division.
The equipment manufacturer suggested the use of an active probe with a high impedance.
It was a fairly rare adjustment.,& quite frankly,"Boss,I need an active probe to this specification" just wasn't going to fly.
The 100:1 had the right input impedance,the display was a bit noisy,but the tweak was "do-able",so it was "all good",& we ended up with a useful probe.