Sensitive LCR Meter Measurements

[Martin72]

The ST28006A test fixture arrived today and I'll be taking it home with me at the weekend.
Here are 2 pictures, from the outside the almost 270€ expensive ST version and mine from Aliexpress hardly differ.
But after opening it....

[KungFuJosh]

How do the plastic holders compare in shape?

[Martin72]

I'll take direct detail/comparison pictures at the weekend, but what I noticed was that the spring is smoother on the ST fixture.

[mawyatt]

You can adjust the spring tension by removing the plunger case and/or the end cap. We prefer more pressure on the DUT for better DUT terminal contact.

Make a shield like the ST version, you can use a Cu plate/foil or just Aluminum L Bracket. Also make sure the 4 BNCs are electrically well connected to the case, and the cover has good electrical connection to the base case thru the 2 screws holding it on.

A little rework and the cheap SMD fixture will be almost as good as the expensive one

Best,

[Martin72]

I think I will install some kind of second housing made of sheet brass.
But first I will repeat the measurements on the ST2830/ET3503, i.e. 10p, 100p and 1n, once with my fixture, then with the ST fixture.
Let's see if we can see anything.

[mawyatt]

A little EM analysis will show that all the case/ground/shield currents return thru the 2 end screws, make sure this connection is really good, one reason we prefer the 4 screw version!!

Best,

[Martin72]

That's a pretty exciting thing, I like that.

My 2nd edition of the power inductor checker has been set up and will soon be put into operation.
If it works as intended this time, I will publish it in the forum.

[mawyatt]

The ST28006A test fixture arrived today and I'll be taking it home with me at the weekend.
Here are 2 pictures, from the outside the almost 270€ expensive ST version and mine from Aliexpress hardly differ.
But after opening it....

Martin,

Something doesn't look right here!!

The ST28006A image shows two end brackets to hold the cover. Each support bracket is bolted to the cover with 2 bolts, yet the image of the ST28006A only shows 1 set of dual bolts at one end of the cover, where's the other bracket attachment bolts at the other end???

Best,