How do u measure the inductance of an air coil?

[QuickStrike]

Anybody knows How to measure the inductance of an air coil, I calculated the value but I want to measure it in practice.


My air coil has 30 turns looks something like the figure below.

 

[Miles Prower]

Use an RLC bridge. If you don't have one, then connect to a capacitor of known value and see what frequency it resonates at.

The best way to measure is to install it where it will be used before doing any measuement since air coils can change value depending on the surrounding environment. Baffle shields, circuit boards, etc. can all act like a shorted out secondary, and that will reduce the inductance below what you'd measure away from any conductors.

For the most part, inductors don't have to be all that accurate. That's what trimmer capacitors are for.

 

[QuickStrike]

- Could please be more detailed as how to measure that resonance (use the oscilloscope??)

- How do I connected it to the capacitor in parallel or in series?

 

[Nigel Goodwin]

- Could please be more detailed as how to measure that resonance (use the oscilloscope??)

The classic way is to use a GDO (originally Grid Dip Oscillator, later Gate Dip Oscillator).

- How do I connected it to the capacitor in parallel or in series?

In parallel!.

But to be honest it seems a fairly futile exercise wanting to know the inductance?, stray capacitances and inductances make any calculations you do at these frequencies wildly inaccurate.

What are you actually trying to do?, is this yet another VHF transmitter?.