My assumption that the bandwidth of the ET35 series is determined by the firmware (and the hardware is always the same) has been confirmed by ET almost involuntarily.
Since I had not yet received a discount on the defective Ethernet interface on the ET3502, I offered to give them the firmware that increases the bandwidth.
They denied this, saying that the internal calibration would then no longer be correct....Aha, so the case was clear.
At first I was tempted to write, give it to me anyway, because the internal calibration is described in the manual.
However, you would need inductances and capacitances with a tolerance of max. 0.02% - never ever...
If I were to buy these references for the different measuring ranges, I would be out a higher 5-digit sum.
No thanks...
What remains is the realization that the bandwidth could be increased to 1Mhz via software, but at the cost of having to recalibrate.
I will refrain from doing so.
The next message was that my suggestions for improvement regarding new features will only be incorporated in a new model series.
So I hope that they will at least tackle the bug with the screenshot function.
Over the next few weeks I will measure more components and compare them with the next best LCR, in this case with the ST2830 at work, and then report back here.
But even so, I can already say that the ET35 is a good device in terms of its basic functions.
Considering the price, a very good one.
I paid a total of 950€ for the ET3503.
For this you get a large, easy-to-read display with a 6-digit display for both the main and secondary parameters.
Internal and external DC bias function up to 40V.
Stepless measuring frequency up to 300kHz.
Numerous correction options.
You can see where you can get a 300kHz device for the money, I can tell you in advance, you won't get one.
These are the advantages, the disadvantages can be summarized in one sentence:
The software is Rigol-style...
And with the same prospect of improvements as the “role model”.
If you like “hard facts” and are looking for a higher maximum measuring frequency and external bias function at the lowest possible price, the ET35 is the right choice.
I'm currently struggling to give a clear recommendation, but what I can say for sure is that the ET35 series is the best you can get for up to €1000.
A little above that is the TH2830 series, for a little more the ST2830 series (same design, but better support).
The series has no Ethernet connection and external DC bias input, as well as a significantly smaller display.
But if 100kHz (or 200kHz “cracked”) is enough, you get a device that is better processed and generally gives the impression that it can do everything it has, quasi the “Siglent” among the LCR meters.
That's my interim conclusion.
The ET3502 is for sale, I will keep the ET3503, even if another LCR meter comes along.
And that will come, because my series of tests between all the “purely” Chinese products has taught me one thing.
I want a “final” device from a renowned brand manufacturer with appropriate support.
And depending on where I can get it relatively cheapest, it will be a Hioki IM3536 or an R&S LCX device.
I won't go below that, I've “seen it all” with the ET35 and the TH/ST28XX.