Korean Multifunction Counter Teardown

[Thomas Scherrer] likes to tear down old test equipment, and often, we remember the devices he opens up or — at least — we’ve heard of them. However, this time, he’s got a Hung Chang HC-F100 multifunction counter, which is a vintage 1986 instrument that can reach 100 MHz.

Inside, the product is clearly a child of its time period. There’s a transformer for the linear supply, through-hole components, and an Intersil frequency counter on a chip. Everything is easy to get to and large enough to see.

Powering it up, the display lit up readily. The counter seemed to work with no difficulties, which was a bit of a surprise.

The oscillator inside has a temperature regulator so that once warmed up, it should be more or less stable. Touching it disturbs it, but you really shouldn’t be making real measurements with the top off while you are poking around on the inside.

This would pair well with a period function generator. Compare it to a modern version.

5 thoughts on “Korean Multifunction Counter Teardown

  1. So even back then they made electronic instruments with mostly empty boxes.

    A while back I was looking around for a bench top DMM, but I could not find any to my liking. The small / “cheap” ones have slow update rates and other limits, which makes them pretty much a handheld DMM in another box. Once you get to more serious instruments, nearly all are half size 19″ rack sized and over 30 cm in depth. Such boxes used to be chuck full of electronics, but now they are mostly empty boxes. I found the Siglent interesting and thought about buying one and sawing half of it’s housing to make it fit. But I decided against doing such a modification of a brand new instrument. As a compromise I bought a Brymen handheld.

    Thomas Schrerrer is a bit of a curious youtuber. He’s got over 800 video’s of different kinds of test instruments. I guess he repairs and sells this stuff again, but I have not looked into details.

    1. “So even back then they made electronic instruments with mostly empty boxes.”

      Sure. Why surprised? Using commonly used standard chassis with good shielding isn’t bad. 🙂
      I really miss those big, boxy instruments these days.
      Their haptics were good. They had a front panel that wasn’t so crowded and you could feel the individual buttons and switches.
      That’s a win for people with larger sized hands or bad eyesight.
      A lot of modern instruments maker could learn from them.

  2. Hung-Chang was quite a prolific company back in the day, they made all sorts of stuff that was badged by companies like Maplin in the UK, decent, reliable and cheap stuff, nice to see some torn down and still working now.

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