Ok, I’ll admit it, this was an impulse buy. I was browsing for an oscilloscope on ebay and saw this LC meter (a tool that measures capacitance and inductance) for 35€ from Hong Kong, shipping included. It’s not the first time I bought something from Hong Kong, it usually takes a month for a shipment to arrive in italy, but there is usually no more duties to pay, so I thought what the heck, let’s buy it and find out what is this all about.
The key features (as noted in the manual) of the meter are:
My expectancies were not high, given the cost and origin (asiatic market tends to overestimate accuracy), but after a month and a week, I was pleasantly surprised: the packaging was quite good, and they even included a USB cable, with a ferrite RF choke!
The case looks custom cut plastic with engravings; sadly, some of them are wrong and misleading, like the one on the power jack, saying 9V AC where, upon closer circuit inspection, 5V DC is more appropriate. Connecting 9V AC could probably fry the meter! The switch is labeled “AC” and “DC” where it should probably be “ON” and “OFF”. So it looks like the case was adapted from another project (or maybe an older revision?).
The five switches on the front panel set the various modes of the meter: The first one, labeled “Zero” effectively zeroes the meter. There is a catch though: you have to keep it pressed until the screen displays “CALCULATING… OK”, or it will not zero correctly. If you keep it pressed a bit longer, the display prints “<DATA SAVED>” And the calibration data is saved to the internal EEPROM. This stuff can be useful if you temporarily use another pair of leads, just zero the meter to nix the effects of the longer wires! When you’re finished you can safely switch the meter off, and the old calibration data will be set on the next power-up.
Second surprise: all five of the switches on the front panel are mechanical! Oh, the good feel :) There were some bad design choices though. The zero switch is momentary, as is the frequency one, the other three toggle. In this way, there are some erroneous combinations, like if you press the “Hi. L” button to enter high inductance measurement, but capacitance is selected on the “L/C” switch! If you happen to hit a wrong combination, the meter warns you, so it’s just a minor annoyance.
Let’s talk about the angle bracket: it feels quite plasticky, fragile. It’s ok if you use it to better see the display, but it will just fall over if you try to press a button (mechanical buttons FTW).
'Tis will be part one. In the next part I will examine functionality, electrical characteristics, and internal construction. Stay tuned and follow! :)