Test Equipment Anonymous

A hamfest or two ago I picked up a couple of inductors because... do I need to spell it out?! Anyway, I like Muirhead and Cambridge Instruments kit.

I checked for continuity but unsurprisingly my cheap component tested didn't bother to measure L. Hence I was dreaming up ways to measure the inductance, but never got around to it.

The, while lazing in the most productive environment known to mankind[1], I finally remembered that I had picked up one of those wretched universal bridges which make you appreciate modern TE: a Marconi TF2700.

The TF2700's spec is +-1%, the 1mH measures 0.99mH (see photo) and the 10*10mH are also all good. Job done, they can be stuffed in the cupboard and left to irritate my daughter when she clears things out.
[1] almost submerged in a hot bath, of course - one of the crowning achievements of civilisation.

The TF2700 is a bit clunky but they do work. I haven't used mine in 20 years.

I'm sure when they came out the ads claimed they could measure the inductance of a paper clip.

Zenith wrote: ↑Thu Aug 14, 2025 9:47 am The TF2700 is a bit clunky but they do work. I haven't used mine in 20 years.

I'm sure when they came out the ads claimed they could measure the inductance of a paper clip.

Back in the day, at my old work, they were the "go to" bridge!

Played around with it again last night.

Some 1µH inductors disguised as resistors with a silver band measured 1.1µH. Can't argue with that.

Some relatively chunky 0.75µH inductors measured around 1µH. Conceivably there is a frequency dependence of the core, but I'm unconvinced.

The slippery slopes of LCR nuttery.

Zenith wrote: ↑Sat Aug 16, 2025 2:00 pm The slippery slopes of LCR nuttery.

R yes, because you can expect sufficient sig fig to be interesting.

L and C unlikely, because <0.5% seems to be "high accuracy".