Time to decide what to do with the Kasuntest ZT102 that I bought to compare against the AN8008. A quick search to see what other had done and I came across this review of the AN8002 which makes reference to my original video.
http://www.markhennessy.co.uk/budget_multimeters/aneng_an8002.htmAstonishing, it had no problems going to 80MHz (yes, mega-Hz). Joe Smith's video (see below) suggests it'll go higher, but beyond that frequency the +17dBm (~1.6V) from my RF generator isn't enough for it. Joe doesn't mention the signal level used for his test.
In the first video I show the meter reading 201.5MHz. The second meter was almost as good. That was with the generator set to 20dBm. Obviously, I never looked at the loading effects.
That was rather surprising, but shows that you can only predict so much from appearances. Remember, this meter has no MOVs or similar, and just a single PTC for protection.
To be clear, there is a clamp after the PTCs. The other leg is protected by the two 5M series resistors. The current input feeds through a two series switches and has a diode from the center node to the common. These are the pads you see arc in Dave's video and the ones that get vaporized in mine.
It took 3kV to damage it slightly, and ~6kV to kill the IC.
Not true. The IC was damaged at 3KV.
And when it was hit with some seriously high energy afterwards, the case remained intact - which is really what safety is about (personal protection, not necessarily surviving electrically undamaged).
These are the kind of comments that make me cringe. I can't disagree that the OP may very well consider the half cycle simulator seriously high energy. I have stated many times that the energy levels in these generators are quite low compared with the actual IEC standards. I've also talked about how my goal was never to run safety tests. The problem I see with the comment is someone not knowing any better may read this and think the meter is well protected for safety and surly it is not. If you want to see case splitting energy levels, my channel is not the place.
Obviously, this is for low energy electronics work only, but having said that, this meter performed really well in Joe's tests, so in reality it appears to be more rugged than you might assume.
I will agree that it is certainly more robust than many of the meters I have tested on my jig. I imagine if the fuse were pulled (from the mA side) the meter would do worse as the switch is breaking down at a very low voltage and that circuit absorbs much of the energy. Removing the fuse, you would increase the gap. Again, breakdowns like this look fine on my little test setup because the energy levels I run at are so low that meters like this and some of the pocket meters actually survive to higher levels that they would with higher energy levels available. The UNI-T UT90A is a great example of how a really bad front end design can act as a clamp and save the sensitive parts. I have tried many times to destroy that meter and because of the limited energy level I test to, it continues to function.
Some off video comments about the AN8002/8.
The LCD is one of the best I've seen in terms of contrast and viewing angle. This is interesting. When I turned on my second ZT102, the first thing I noticed was how poor the LCD looked. I also noticed that the switch did not feel near as smooth as the first one. I swapped the LCD from the original meter which had no effect so something else has changed. I also took apart both switches and noticed that they had changed the springs. One set are silver, the other copper colored. I saw no other difference.