Inductance Measurement

[dmonarch]

Hi. I am at the moment trying to reproduce Eric Dollards Analogue computer for longitudinal electricity. I have some inductors, well in fact some small transformers however i am only using one side of the transformer and treating it like one coil. Not sure if i am meant to short or leave floating the other coil.
Anywhos i am failing to get it into resoancne. When i measure the coil resistances they are all the same however when i measure the inductance of each coil the coil values are quite spread out. Is this normal or is my meter rubbish. Can anyone recomend a precision inductance meter.
Looks like i am going to have to make some variable inductors myself which is a bummer.
Cheers
Damian

[Web000x]

A wooden broom handle works great for making a bunch of variable inductors. Simply cut it into smaller sections, Run a drill bit through the center of it lengthwise, and bore a bobbin cavity with a grinder. I cut a broom up and got about 15 variable inductor bobbins. It is a little tedious, but it is good for a homemade product.

Dave

[Inquorate]

Variable inductors

This link will help;

Pronine Electronics Design - Single-Layer Air Coil Calculator

Variable inductors are a pain, but easier to make well than variable capacitors

[nvisser]

Have a look at the end of page 1 and page 2 of this document. Electronic tools for resonance
http://www.byronwine.com/files/plans.pdf

[dmonarch]

Thanks

Thanks guys