This one has been sitting since the summer- it took a while to get all the rain to evaporate from the inside! When I grabbed the pour fella, it had water up to the mirror.
The latest addition to our vintage collection is a Keithley 130A handheld DMM from the mid-eighties.Keithley is not well known for its handheld DMMs, or at least I’ve never heard of them. It’s a 3.5 digit 0.25% instrument made in mid 1980s
Today’s teardown subject has been waiting for its turn for a while- I picked it up at the last Design East conference in Boston in 2012. There, Microchip and Energizer were talking about low power design and using these Schick Hydro 5 power razors as an example. Hot on the heels of my repair of a Philips Sonicare toothbrush, this seems to be a good fit for a comparison. Both things do essentially the same thing- they shake, light up some LEDs and not much else.
Another ebay find- a vintage Keithley 172 multimeter. The datecodes on the parts range from 1978 to 1984, placing the final assembly somewhere in mid-1980s. It seems fully functional, but could use a bit of a calibration to regain its past precision.
This unit was used for a few years with a very limited success until I finally got fed up and decided to peek inside. The always warm case and constant 7W power draw did not help its cause either. As one of the 2 star reviews on Amazon concluded- don’t bother buying one of these.
An ebay find made its way into the lab- an industrial quality DMM from Hioki, made in 1984! The meter has some pretty good specs as shown in this datasheet:
- 3.5 digit (1999 count), 0.5% on DC voltage
- 20uA DC current range with 10nA resolution
- 1G input resistance on 200mV range
- Drop proof to 1 meter
- Dust sealed.
- 500 hours battery life using 2 AA
- Neon indicator of overvoltage Continue reading
Today we are unpacking a brand new LCR meter from a company called Tonghui in China. It was purchased on ebay and took less than a week to arrive.
Today’s quick visual teardown is of an 1984 vintage Keithley 197 microvolt DMM, Despite considerable age, it’s still quite alive and kicking and very useful for measuring low currents and voltages.
Today’s quick teardown target is a 1985 vintage electronic load made by Kikusui of Japan. It came from eBay with a noisy fan, but was otherwise fairly functional despite the considerable age.
In the usual Kuzyatech fashion, when something breaks, we must take it apart. Today, one of the “early adopter” GU10 style LED lamps decided to fail mechanically: