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Products => Test Equipment => Topic started by: strantor on April 18, 2014, 02:25:56 pm

Title: Please suggest a 4ch scope with isolated/differential inputs
Post by: strantor on April 18, 2014, 02:25:56 pm
I use my scope mostly to test variable frequency motor drive output in the field, so I need something with isolated/differential inputs and as reasonably portable as possible. I currently use a Tektronix THS720P provided by my employer and I am happy with it, but I would like to ween myself off of employer-provided tools and upgrade to 4 channels. I have been looking around and I am aware of the Fluke Scopemeter, the Tektronix THS3000 and the Tektronix TPS2000. I would like any of those, but the price is more than I can afford; So I am looking for similar offerings in the cheaper brands like Rigol, Owon, etc., but I cannot find anything with isolated channels from those guys. I am willing to buy used.

Here are my requirements:
must have 4 (or more) isolated/differential channels

 Here are my desires:
I would like to spend <$1,500USD if possible.
100MHz or better preferred
decent single shot sample rate and buffer size
MSO/logic analyzer digitial inputs would be cool, but I'm pretty sure this doesn't exist in scopes with isolated channels
export data to PC by any means (CF card/usb/ethernet)
Handheld form factor if possible; if not possible, then at least Smaller than a giant bench unit (ex: tps2000 is acceptable)
Cool features & measurements (ex: tps2000 with  TPS2PWR1 plug-in option calculates power factor, transistor switching losses, etc.)


Or, if anybody knows of a 4 channel differential-interface-module-type-thingamajig, that would allow 4 differential measurements on a ground-referenced scope, that would be cool too; probably doesn't exist since I just dreamed it up. That would be much more awesome than buying 3 or 4 differential probes.
Title: Re: Please suggest a 4ch scope with isolated/differential inputs
Post by: strantor on April 18, 2014, 02:29:26 pm
Oh, forgot to mention; PC-based scopes are acceptable (even preferred, if the specs are right - so far I haven't seen one that wasn't pathetic and overpriced).
Title: Re: Please suggest a 4ch scope with isolated/differential inputs
Post by: tautech on April 18, 2014, 08:10:36 pm
4 isolated channel handheld 100 MHz scope, yep that would be nice. Not sure they exist.

Check out the Siglent isolated channel hand helds.
http://www.siglent.com/en/product/detail4.aspx?id=100000001577369&nodecode=119008004 (http://www.siglent.com/en/product/detail4.aspx?id=100000001577369&nodecode=119008004)

They also have 2 Ch ISFE (isolated front end) units.
http://www.siglent.com/en/product/detail5.aspx?id=100000013462552&nodecode=119008006 (http://www.siglent.com/en/product/detail5.aspx?id=100000013462552&nodecode=119008006)

And you have a US agent on this forum
Title: Re: Please suggest a 4ch scope with isolated/differential inputs
Post by: The Electrician on April 18, 2014, 08:51:22 pm
You're not going to find a 4 channel isolated input scope with 100 MHz bandwidth for <$1500 new, so used is going to be your only option.

I see some TPS2000 series units for about $2k on eBay.

I think the THS3000 are too new for many to show up used yet.
Title: Re: Please suggest a 4ch scope with isolated/differential inputs
Post by: casinada on April 19, 2014, 01:28:20 am
The only thing affordable is the Hantek 1000S series but is only 2 channels.
http://www.hantek.com/en/ProductDetail_18.html (http://www.hantek.com/en/ProductDetail_18.html)

I have a scopemeter 199C and is great. I also purchased a 100:1 probe that is of decent quality and looks like the Fluke probes.
http://www.ebay.com/itm/GRS-5KV-300MHz-High-Voltage-Oscilloscope-Alligator-Clip-Probe-P2300C-100-1-/370860980991?pt=LH_DefaultDomain_0&hash=item5659097aff (http://www.ebay.com/itm/GRS-5KV-300MHz-High-Voltage-Oscilloscope-Alligator-Clip-Probe-P2300C-100-1-/370860980991?pt=LH_DefaultDomain_0&hash=item5659097aff)


Title: Re: Please suggest a 4ch scope with isolated/differential inputs
Post by: BravoV on April 19, 2014, 09:37:49 am
Quote from: casinada on April 19, 2014, 01:28:20 am
I also purchased a 100:1 probe that is of decent quality and looks like the Fluke probes.
http://www.ebay.com/itm/GRS-5KV-300MHz-High-Voltage-Oscilloscope-Alligator-Clip-Probe-P2300C-100-1-/370860980991?pt=LH_DefaultDomain_0&hash=item5659097aff (http://www.ebay.com/itm/GRS-5KV-300MHz-High-Voltage-Oscilloscope-Alligator-Clip-Probe-P2300C-100-1-/370860980991?pt=LH_DefaultDomain_0&hash=item5659097aff)
I'm interested, is this probe has switchable attenuation levels or its fixed at 100:1 ? (I prefer fixed one)

At that ebay page, it says at the specification -> System bandwidth:  10X:DC-300MHz , is that just a typo ?
Title: Re: Please suggest a 4ch scope with isolated/differential inputs
Post by: casinada on April 19, 2014, 04:12:55 pm
it is fixed.
I have the P2300C (300Mhz)
There are 4 models:
P2300C (300Mhz) 100x1
P2500C (500Mhz) 100x1
P2300B (300Mhz) 10x1
P2500B (500Mhz) 10x1
Title: Re: Please suggest a 4ch scope with isolated/differential inputs
Post by: strantor on April 19, 2014, 06:49:43 pm
Is that ebay probe double-attenuated like a probe for differential input scopes should be?