Coil tester SRF/Inductance/distributed capacitance

[Vadim18]

Here is mine inductor tester with ability to measure SRF, with nice tolerance and stable output waveform.
Based on well known LC generator circuit, but modified by ukrainian author to nicely measure inductors.

Frequency meter and calculator needed.
Here is simple formula: 1/F^2
Mainly tolerance depends on how precisely C1 capacitance set to 25530 pf, and by frequency meter error.

I make this one around 8 years ago, for FM discriminator coil tuning (for DBL1018 chip).
I tested some inductors and get this result.

333J -> 32,116 mH -2,7% error
50 +-?% -> 47,496 uH -5% error
18 +-5% -> 17,26 uH -4% error

Original source http://www.cqham.ru/ot09_2.htm

[Skippy]

An English translation of the above Russian project:

http://translate.google.pl/translate....ru/ot09_2.htm

[Vadim18]

An English translation of the above Russian project:

http://translate.google.pl/translate....ru/ot09_2.htm

Thanks for your interest, and english translation.

[KingJL]

Here is mine inductor tester with ability to measure SRF, with nice tolerance and stable output waveform.
Based on well known LC generator circuit, but modified by ukrainian author to nicely measure inductors

Frequency meter and calculator needed.
Here is simple formula: 1/F^2
Mainly tolerance depends on how precisely C1 capacitance set to 25530 pf, and by frequency meter error.

I make this one around 8 years ago, for FM discriminator coil tuning (for DBL1018 chip).
I tested some inductors and get this result.

333J -> 32,116 mH -2,7% error
50 +-?% -> 47,496 uH -5% error
18 +-5% -> 17,26 uH -4% error

Original source http://www.cqham.ru/ot09_2.htm
[ATTACH]50660[/ATTACH]
[ATTACH]50661[/ATTACH]
[ATTACH]50662[/ATTACH]
[ATTACH]50663[/ATTACH]
[ATTACH]50664[/ATTACH]
[ATTACH]50665[/ATTACH]
[ATTACH]50666[/ATTACH]

How about an updated version using the same concept:

[6666]

How about an updated version using the same concept:
[ATTACH=CONFIG]50675[/ATTACH]

Thanks

[Vadim18]

Yes, it looks more modern, only 3 volts, but i see no amplitude stabilisation and no output buffer.Last one may afect frequency meter reading. Also lt1016 are quite not cheap.
But in the name of precision lt1016 can do work more better since it all integrated, compensated and have other good things.