RLC Bridge

The first link is a Tonghui. I had the TH2821A until it failed. I don't think it was the meter's fault. The wall-wart apparently failed with high voltage or ac or something which blew the ripple filter capacitor inside the meter and then some other components as well. It was a no-name wall-wart.

The meter itself was very good and gave reasonable readings. Tests with other instruments indicated it was accurate. My model was portable which was a great convenience to me.

I've got a GenRad 1693 DigiBridge, and it seems to work quite well. I probably only know how to use about 10% of its actual capabilities.

Jon

We have a GW-Instek LCR-819, other than a bad lcd initially, it works quite well. Has a higher frequency, ~100khz. But it will set you back $1800

Cheers

For bench use, I'm a fan of the Advanced Devices Smart Tweezers. They're expensive for a handheld device, about $400, and I wouldn't rely on their calibration to the 10 ppm level, but for most things they're the proverbial bee's knees.

Cheers

Phil Hobbs

I have an old "manual" ESI bridge (skill required to use, trust me) and a ESI 2100 video LCR. ESI stuff goes on ebay all the time. They must have sold a lot of LCR bridges, calibrators, etc.

HP sold a lot of those 4263 meters. Maybe $1200 used. The ESI will be cheaper and probably as goood.

I'd be more inclined to go used name brand rather than no-name new, though in theory it shouldn't be all that hard to design a decent LCR meter, especially at frequencies like 100kHz and lower.

I don't hear good things about SRS in general, so I avoid their gear. I will say their arbitrary waveform generators seem fine. I don't own any, but have used them at various places.

We've got an SRS 720 LCR meter. It seems to work pretty well. I think it gets confused with big inductors sometimes. (But then again I may not be 'flying' it correctly.) (I guess I could try reading the manual. :^)

George H.

One BIG problem with L meters: the core permeability usually varies dramatically with frequency.

Sweeping or scanning is often appropriate.

The 720 has selectable frequency.. 100Hz, 120Hz, 1kHz, 10kHz, 100kHz IIRC. Kind of a 1980's design, but they seem to work okay.

Their probes are horrible.

These look interesting.

Has anybody used these, or something similar?

We bought a new SRS digital LC bridge, and we're sending it back. It's pretty awful.

Try this one, it works for me:

Cheers, Harry

Yikes, that's almost $10K. 30x the price of the TH2811.

We need this mostly for receiving inspection. We occasionally get a reel of parts that are way out of spec, so we test a few off every reel. The little tweezery things aren't very accurate for inductors and low-q caps.

We work mostly in time domain have little use for a VNA sort of thing. I mostly use pulse generators and TDR to characterize parts in engineering.

"John Larkin" wrote in message news: snipped-for-privacy@4ax.com...

The "2811" type (from your first and second e-bay links) is a generic LCR meter that seems to be very common in China and so it's often exported. If you search for "2811 LCR" on a chinese shopping website, you'll see dozens of (sometimes) differently looking "2811"s from various makers, usually prefixed by 2 letters and suffixed by 1 letter like TH2811C, JK2811C, LW..., ZC..., RK... etc. The first letters are a short form of the manufacturer's company name and the last letter (if there is one) is usually some form of a hardware revision. Things like copyright don't mean much in the chinese test & measurement market, so lots of companies make instruments that are very similar, have the same basic circuitry and specs, and mostly only differ by enclosure, arrangement of the items on the front panel and such. They all stem from a (sometimes quite old) basic design, usually designated by the same 4 digit number to be easy to recognize. As soon as a new measurement instrument (of whatever type) becomes popular, there are a lot of "second sources" with the same type number and different first 2 letters, and even when the original maker stops making it, others often continue production until the thing really gets out-of-fashion. Sometimes the remakes have more functions than the original (commonly denoted by incrementing the last letter). In a way, "a 2811 LCR meter" is like "a 2N3055 transistor". They are all similar, have essentially the same (quite loose) specs, but depending on who makes them, there are varying stages of quality control that range from "reasonably good" to "none at all".

I'm not sure, who started making the "original 2811". It could likely be Shanghai Xinjian Instrument, but that's just my guess. If so, they are still making it (the XJ2811C). It's not easy to find in online shops.

As for the others, the Tonghui versions (TH2811x) will probably be OK, their quality control seems to be reasonable, at least judging from their voltmeters.

Myself, I haven't used any "2811". I have, at a time, considered to buy one of some variety, even looked up various manufacturers (that's where the info above comes from), but ended up buying an LCR700 from Sanwa (Japan) instead.

The LCR700 works and does so reasonably well. It has a stated basic accuracy of 0.3% (vs. the 2811s that are supposed to have 0.2%), but given the dubious provenance of many 2811s (especially those not from Tonghui or Xinjian), it would likely outperform them anyway. Watch the frequency range though - there is a table in the LCR700's manual as to what test frequencies should be used for what L/C value ranges and the achievable accuracy for each range and frequency. The LCR700's other downside (that I noticed so far) is that it does not include a set of kelvin-connected tweezers for testing SMT parts. There exist separately available SMT tweezers though.

Dimitrij

Try this one, it works for me:

Cheers, Harry

Yikes, that's almost $10K. 30x the price of the TH2811.

We need this mostly for receiving inspection. We occasionally get a reel of parts that are way out of spec, so we test a few off every reel. The little tweezery things aren't very accurate for inductors and low-q caps.

We work mostly in time domain have little use for a VNA sort of thing. I mostly use pulse generators and TDR to characterize parts in engineering.

John Larkin Highland Technology, Inc

Time domain with flux capacitors huh. Once you plot, graph your part on the frequency domain, or voltage domain, seeing large changes, the TD will make more sense. Biggest problem I see is the voltage coefficient in MLC caps. Put that in your TDR and smoke it. Cheers, Harry

Agreed! Particularly after sneezing on the stash of 0402 resistors.

Right on the frequencies... useful for most 'audio' range stuff.

RE probes: I've got a little piece of white proto board with wires that plug into the input. But 'thinking out loud' maybe I could hack in a switch to some other probes... mini grabbers or surface mount tweezers.

George H.

At that price, you are competing with some boat anchor network analyzers. You would need an impedance bridge and calibration standards for some models. [Best to get it when you buy the analyzer.]

I see a lot if 4195s on ebay. I'd sure hate to pay shipping on one of those. But many of these network analyzers are in the bay area. It has device modeling software built into it. You sweep the part and it creates a LCR model. The 4195 needs an impedance bridge.

I got a HP 4192A off ebay a few years ago. Bit of a beast of course but fun to use. It is very flexible, things like an adjustable bias voltage, so you can say measure a photodiode capacitance at -30V. Or indeed plot it, step through a range of voltages.

I have a HP 4192A, I wonder if there is some software to extract a model like that. I suppose I should learn the maths and write it.

• Engrish, anyone?

• Closest to engineering English of the three.

• Also decent English.

VNWA from SDR-Kits....

cheap and great fun... not only for component-testing

hth

- Michael Wieser