I know a few chaps have suffered from this with the 5000, we have not at all on any of 5/7 and 8000 Rigol models.
Interesting you say this ...
I had been watching (several times) various teardowns on 5000 and 7000
- as the 5000 was released after the 7000, Rigol appears to have made some mods in general shielding and power distribution
- at least different to the 7000
- better in MHO ...
That said, I'm thinking that the RF susceptibility could be software related ??
How could that be, you might ask?
Well one thing that comes to mind
- if I configure the front-end ASIC to 'listen' on FULL BW its capable
- sure I'm going to 'open the door' for some unwanted RF to enter
To mitigate this (an example), one would limit the front end ASIC to only listen for the MSO's defined BW.
Maybe this is already implemented
- just thinking aloud here
- as to why some of the 5000's could have this problem with stray RF fields
Another potential problem is ‘poor’ power supply filtering.
Under static (non RF field testing) the PSU can pass with flying colours.
However if ‘stray RF’ (even low level pulse) enters its ‘control loop / regulation’ subsystem
– this will manifest in all sort of potential problems with the signal processing of the MSO.
One quick fix (very easy and low cost)
- is to put the ‘supply’ cable which plugs-into the main board through a large Ferrite Core for Power Supply Decoupling (see attached picture)
– doing this can only improve and protect from any future problems.
Anyway, it will be interesting to see if the general susceptibility of the 5000 to RF is related to early batch or FW revisions.
I wonder if they ‘changed’ the revision on the PSU from the early release HW to current release??
OR
– the overall HW revision designation
– also covers the PSU changes??