I have built amplifier's where I calculated the specific needs for
inductance for the tank circuit. I then tried several ways to measure what
was then used in the tank coil, simply to verify the results. I had two
digital meters for measuring LCR components, but the ability to measure
inductance was poor at best, when you looked at a few uH. I then found a
General Radio 1656 Inductance Bridge and bought it, and quickly discovered
trying to use it at the very limits of its rated inductance range ( 1 uH )
was something that produced less than repeatable results. I had no
confidence in it.
Every couple of months I would search ebay in their used test equipment
area, just to see what else was on the market. By accident, I then found a
circuit on-line where a fellow used a couple of IC's and a higher measuring
frequency, and then "measured" the inductance using a frequency counter.
It really looked better than what I had, since it was supposed to measure
down to .1 uH. I was making plans to build it, however, I then stumbled
across an add on ebay, for a small unit, possibly similar to the circuit I
found by Googling, but it was more advanced and provide a direct read-out in
uH and Pf.
I ordered it and also ordered a bunch of 5% axial lead inductors in the .82
uH to 22 Uh range. Today this little device arrived from Hong Kong. I
quickly plugged it in and pulled out the 5 bags of 5% inductors. It took
about 3-5 minutes to find the proper way of zeroing it out on inductance. I
then measured each of the 5% inductors. All five inductors measured within
5% or less of their correct value. At the moment, I am pleasantly
For me this is a real positive step, simply because I enjoy building so much
and I also like to know what the actual component value is, via an actual
measurement. At this moment I think I can now measure inductance down to
less than 1 uH with reasonable accuracy.
The unit was $39.98 total price with shipping, and took 2 weeks exactly to
arrive. The component quality and construction appear to be very good.
Lots of people seem to be selling this same unit on ebay, here is a link to
the source I got mine from, if you have a need or interest:
I hope this helps a few of you,
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