EEVblog HVP70 Differential Probe

[Monkeh]

Amplitudes are on scope different due to scaling settings, yes.  Amplitudes between diff probe and and direct measurement are different due to the diff probe scaling the voltage into a range of 0-7V.

It's not scaled into 0-7V, it's x10 or x100 attenuation. That or it's a very odd device.

Test the probe with a known clean source - stuffing your mains through an isolation transformer is not the same as looking at it with a normal probe.

[LabSpokane]

See above.  User error.  I had the scope input set for AC instead of DC coupling.  DC coupling is the correct setting since the output is single-ended. 

[LabSpokane]

Amplitudes are on scope different due to scaling settings, yes.  Amplitudes between diff probe and and direct measurement are different due to the diff probe scaling the voltage into a range of 0-7V.

It's not scaled into 0-7V, it's x10 or x100 attenuation. That or it's a very odd device.

Test the probe with a known clean source - stuffing your mains through an isolation transformer is not the same as looking at it with a normal probe.

Ignore that.  I should never answer a question in a hurry.  You are absolutely correct.  I was referring to the amplitude of the actual mains voltage versus the probe instead of the 1:10 signal into the scope. 

[mtdoc]

On the attached image, green is the isolation xformer output.  Yellow is the diff probe. 

I assume the difference in displayed amplitude is due to scaling differences. Are the actual amplitudes the same?

Its not the amplitudes in question but the distortion, some slew rate limitations and odd corners in the peaks (recovery from the slew limiting?).

Yes, I realize distortion was the original point, but my question was about amplitude.

So accounting for scaling differences, what is the difference in amplitude? (either with or without isolation transformer).

[LabSpokane]

On the attached image, green is the isolation xformer output.  Yellow is the diff probe. 

I assume the difference in displayed amplitude is due to scaling differences. Are the actual amplitudes the same?

Its not the amplitudes in question but the distortion, some slew rate limitations and odd corners in the peaks (recovery from the slew limiting?).

Yes, I realize distortion was the original point, but my question was about amplitude.

So accounting for scaling differences, what is the difference in amplitude? (either with or without isolation transformer).

Dead issue.  I had my probe input setup incorrectly, despite the fact that it was literally staring me in the face.  The device is in perfect working order.  It's user ... is another discussion entirely.   

[mtdoc]

Dead issue.  I had my probe input setup incorrectly, despite the fact that it was literally staring me in the face.  The device is in perfect working order.  It's user ... is another discussion entirely.   

OK, got it. No worries, I have a lot of experience with the same kind of "intra-cerebral device error".

[serggio]

Subscribing   

[BU508A]

In case anyone is looking for a case for their new probe,  I've ordered on of these inexpensive cases from eBay.  They should work well for Dave's probe a well.  I'll report back when I get mine.

Just following up on this. After a month this case finally arrived. It's a nice case. Unfortunately it's just a bit too small for my Tek p5205. I thought it would work based on the listed OD but the shell is thick enough that the ID is significantly smaller.

The inside dimensions are 8 1/8 " x 3 3/4" x 1 1/2".    Not sure if that will accommodate the HVP70 or not.

It does fit my Tek A6302 current probe quite nicely, so I'll keep it for that.

I've bought this case for my EEVBlog HVP70 probe:

http://www.ebay.com/itm/222524750968
It costs EUR 16,54 / ca. U$ 18,60
and I'm very pleased about the quality.   

Here are some pictures:

[Monadnock]

I got an email this morning, supposedly from Dave, saying the BARGAINPROBE discount was working again, but when I went to check out it said that the discount use limit had already been reached.

Anyone else get this email? I'm wondering if it was spam.

[rsjsouza]

I got an email this morning, supposedly from Dave, saying the BARGAINPROBE discount was working again, but when I went to check out it said that the discount use limit had already been reached.

Anyone else get this email? I'm wondering if it was spam.

I got this e-mail today as well but I haven't tried to use the code. I just did and it worked for me.

[Monadnock]

I got an email this morning, supposedly from Dave, saying the BARGAINPROBE discount was working again, but when I went to check out it said that the discount use limit had already been reached.

Anyone else get this email? I'm wondering if it was spam.

I got this e-mail today as well but I haven't tried to use the code. I just did and it worked for me.

I got that far as well. It didn't strip out the discount on me until I clicked PayPal to pay.

It would of been better if it just refused to accept the code instead of accepting it and then taking it out when you go to pay.

[neslekkim]

In case anyone is looking for a case for their new probe,  I've ordered on of these inexpensive cases from eBay.  They should work well for Dave's probe a well.  I'll report back when I get mine.

Just following up on this. After a month this case finally arrived. It's a nice case. Unfortunately it's just a bit too small for my Tek p5205. I thought it would work based on the listed OD but the shell is thick enough that the ID is significantly smaller.

The inside dimensions are 8 1/8 " x 3 3/4" x 1 1/2".    Not sure if that will accommodate the HVP70 or not.

It does fit my Tek A6302 current probe quite nicely, so I'll keep it for that.

This was actually a very nice case, the probe fits perfectly into it. Would be nice if it was teensy bit longer, but no problem packing it and closing the case.

[bitseeker]

8-1/8" long does seem a bit tight. The leads must get pretty well bend to fit. I guess I'll look for something a bit longer. For now, I just pack it in my scope's bag.

[neslekkim]

It looks like this:

[bitseeker]

Thanks for the photo. Looks like it works better than a ruler would lead one to expect. Nice.

[EEVblog]

It looks like this:

Nice.

[EEVblog]

FYI I'm having a 15% sale on the EEVblog store including the HVP70 probe.
Use the coupon code hardfork

https://www.eevblog.com/store/

[EEVblog]

Is it supposed to work in your EEVBlog store on Ebay? Because it didn't work for me. I might have made a mistake typing it in but I don't think I did and it blanked it out when telling me it wasn't valid.

It was just a bunch of fuses.

No, only my web store

[NiHaoMike]

Any teardowns? I opened up mine but didn't go any further once I found that the shielding is soldered on.

I think it's a good product, but I would have liked it better if the banana jacks were on the isolator box instead of the probes themselves. Making the BNC cable detachable would also be good, but I can understand that doing so will add cost.

For a test, I probed the mains with a Homeplug adapter streaming a TV show. The packets look tiny compared to the mains, so I put together a frequency dependent attenuator to make the packets easier to see.

[tautech]

I like the Pintek ones better.

They are clones of Sapphire:
http://www.sapphire.com.tw/notify.pdf

Actually not.

The pdf linked refers to Pintech.
Pintek and Pintech are two different companies, one in Taiwan as Sapphire are and Pintech famous for copying Pintek and apparently Sapphire too are in China.

[bicycleguy]

Ordered from EEVblog Nov 5th, received Nov 13th, DHL to USmail,  US$ 379.82 via PayPal

Amazon was asking $650 at the time, now they are asking $450 ?

Seems nice, solid, nice detachable probes.  Here's a picture of the 60hz 120VAC at the wall outlet compared to a nice sine wave.  Is home power always this distorted?  This was in the evening so no solar distortion.

[bicycleguy]

Ordered from EEVblog Nov 5th, received Nov 13th, DHL to USmail,  US$ 379.82 via PayPal

Amazon was asking $650 at the time, now they are asking $450 ?

Seems nice, solid, nice detachable probes.  Here's a picture of the 60hz 120VAC at the wall outlet compared to a nice sine wave.  Is home power always this distorted?  This was in the evening so no solar power generation distortion.  Be neat to see a separate thread on where in the world the worst distortion is.

[TheSteve]

This is what the AC currently looks like at my place (different differential probe) - minimal load at the moment.

[David Hess]

Here's a picture of the 60hz 120VAC at the wall outlet compared to a nice sine wave.  Is home power always this distorted?  This was in the evening so no solar distortion.

In my experience it is usually even more bent at the top of the leading edge do to non-linear rectifier-capacitor input filters.  Things may have improved with more power factor corrected loads.

[Dubbie]

Has anyone found any nicer probes for the thing?

I really don't like the ones that come with them. They are really hard to open up sometimes if you are in a tight space or funny angle.