LC100A Terminals on the Right

I've just tested a LC-100A, one with the Test terminals on the Right. See the pictures.

Several people recommended this type of meter as being accurate but often their review has no attempt to define how accurate. I have only tested this one. I can not point to a reliable supplier, it is possible that others looking identical may not perform similarly. This is not a laboratory test, just using some components from my large "junk box".

March 2023:- This is still sold by the supplier linked lower on this page.

I have only tested low values such as will be used for HF radios.

I have used some capacitors marked 1% and 2% and a few carefully measured inductors (using a dip meter with the 1% capacitors as a reference).

For accuracy when using a dip meter the frequency is monitored on a SDR. The meter is held steady when the best dip is found then the frequency read from the waterfall.

Test Frequency

Often this type of tester is criticised because it tests at a few hundred KHz not at the working frequency. I have not seen any difference when testing normal HF coils and capacitors at normal HF frequencies.

Typical results:-

Note:- USE 5 VOLTS. The DC socket is for 5 Volts input, about 50mA regulated. To be safe use the USB socket to a USB port. The USB is for power only.

On power-up a message shows "LC Meter LC100A Rev 4.8"

Press the "Cal" button for a few seconds before measuring. It says "CALIBRATING" and after about a second "OK". Holding the "Cal" button for longer gives a "Saved" message, maybe writing the calibration factor as default.

A small amount of zero drift was noted until after about 15 minutes "warm up" it was stable.

NOTE This meter does not show negative readings. Other similar testers do, indicating negative drift while operating. 0.00 may not mean that calibration has not drifted, calibration must be made regularly.

There is a small amount of sensitivity to the proximity of the tester's hands. While this is very small it might be reduced if the unit is built into a grounded metal box.

Mine was obtained from here https://www.ebay.co.uk/itm/LC100-A-High-Precision-Digital-Inductance-Capacitance-L-C-Meter-new/141694464845?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649 There is no way of guaranteeing another "Right Handed LC100A" will be similar to mine. I'd recommend a test with at least one close-tolerance component.

Seller's Product Features (This one does not make any accuracy claims apart from "High Precision".)

ICSH014A is a “Capacitance, Inductance Measuring” module.

Engaged in the development of electronic engineers often need to measure inductance and capacitance, and inductance capacitance meter sold on the market price is higher, and the measurement of small capacitance inductance and small error, this instrument based on LC resonant principle, join the accurate measurement of high-speed micro controller calculation, small capacitance can be measured the inductance 1uH and less than 1pF, the maximum this is also the characteristics of the instrument, particularly suitable for microwave production and switching power supply transformer, inductance measurement.

ICSH014A (LC module) with four measuring mode:

1.C mode...... Capacitance (0.01pF-10uF).

2.L mode...... Inductance (0.001uH-100mH).

3.HL mode...... Large inductance (0.001mH-100H)

4.HC mode...... Large capacitance (1uF-100mF)

All stalls are automatic range, the use is very convenient. In this way, ICSH014A Whether from the measurement range and measurement precision can completely replace any kind of inductance and capacitance measuring instrument on the market, the performance parameters to the digital bridge, is a highly cost-effective instrument.

ICs on board

STM8S micro

LM311

LM393

There is a similar "LC100" available but of different construction with the test terminals on the left under the display. Others have confirmed that this variant is not accurate although the supplier says 1% the one I tested was reading more like 20% low.

http://www.dl0hst.de/mini-ringkern-rechner.htm Mini Ring Coil Calculator, turns and length of wire. Scroll down for English etc.

https://sites.google.com/site/vk3bhr/home/lcm1  A similar, slightly better, home built LC meter design that I built.

Or, On line http://toroids.info/

G4ZFQ June 2019