Let's get Slider (aka Mark Vaughan) a nice 4-channel DSO with math functions!

[Jeg]

A very interesting article by Doug Ford on oscilloscope probes.

http://www.dfad.com.au/links/THE%20SECRET%20WORLD%20OF%20PROBES%20OCt09.pdf

he says......."I dissected the cable further and was surprised to discover that the core wire appeared to be very thin resistance wire, with
a resistance of around 100~200  per metre! See Fig.8. This very fine core wire appears to be made from a single
strand and is "crinkled" – presumably to provide tolerance to repeated flexing......."

Does anyone has an idea on where to search for a cable like that?

Tnks

[TinselKoala]

That's why it is so hard to repair good probes, they use that wire, which solder doesn't stick to.

I haven't been able to find a source for that wire myself. But it's not really needed for low-bandwidth probes; you can make your own simple probes using regular 50 or 75 ohm coax.

For example,
http://cromwell-intl.com/radio/probes.html

[Jeg]

Tinsel I managed to order two p4100 probes from eBay through a friend of mine who lives abroad. But still want to mess with HV with better response than P4100 at frequencies up to 50MHz which is the limit of my rigol. (I still don't believe that I have a scope like this on my bench). I will also fix my old analog one and any signal before going in to the new DSO, it has to pass first from the old analog.  What I learned from this, is that analog scopes can be fixed easy because they have an input channel board which takes all the HV.
If hv pass in to the DSO then start crying before even see what happened 

[TinselKoala]

Tinsel I managed to order two p4100 probes from eBay through a friend of mine who lives abroad. But still want to mess with HV with better response than P4100 at frequencies up to 50MHz which is the limit of my rigol. (I still don't believe that I have a scope like this on my bench). I will also fix my old analog one and any signal before going in to the new DSO, it has to pass first from the old analog.  What I learned from this, is that analog scopes can be fixed easy because they have an input channel board which takes all the HV.
If hv pass in to the DSO then start crying before even see what happened 

The 50 MHz bandwidth of the DS1054Z doesn't mean that that is the "limit" of the scope. Oscilloscope bandwidth is usually defined as the 3db rolloff point of amplitude of a sine wave signal. That is, as the signal gets higher and higher in frequency, the scope will show it at lower and lower amplitude, and when the amplitude of the displayed signal is 3dB less than the true value of the signal, that is considered the "bandwidth" of the scope. The scope will still work at higher frequencies though; it's just that the display of the higher frequency signal components is attenuated more or less.

The good news is that the Rigol is conservatively rated; the 3dB rolloff point is more like 60 MHz for sinewaves. The even better news is that the scope can be "unlocked" to give 100 MHz bandwidth, which is also conservative; some people who have tested the "unlocked" scope have found that the 3dB rolloff point is over 100 MHz.

Once you've got your scope "burned in" and are past the vendor's guarantee (30 days here in the USA from TEquipment), and you know you aren't going to have to return it under the Rigol factory warranty, you can easily unlock your scope to add the 100MHz bandwidth and the advanced trigger features.

Yes, I agree about using the Analog scope on the HV measurements first... they are usually repairable if something goes wrong. I wouldn't even know where to start repairing the Rigol's front end if it failed from overvoltage on the input, though.

[Jeg]

Very nice info Tinsel, thank you!
Do you have any video of yours working on the FFT capability of the Rigol?