Variable Inductor Substitution

Hi,

I have a quick question for the EE experts here.  I'm looking to source parts for the old EM Theremin design updated using the hot rodding schematic.  So I'm looking for 47uH variable inductors.  Seems like most of the ones I can find out there are low-Q IF transformer style inductors which I'm not too comfortable with.  

I would like opinions on substituting the following Vishay variable inductor.... http://www.vishay.com/docs/34086/wvl.pdf   I have found a good source but have to buy in bulk so I'd really appreciate any advise before committing.

Thanks.

Why not take the original parts?

Its part # on the following website is EZ-1017 and can be ordered online even in small quantities:

http://www.jabdog.com/toko-ez.htm

Not ideally suited, but I have 100+ 5p series Toko variable inductors.. 39uH (about 24uH to 45uH adjustment range) Q=55 (min) Test Frq = 2.52MHz Data Here.

I am happy to supply these in packs of 5 - just email me and I will advise how by donating a minimum of £2 to streekidsrescue.org, and paying the postage, you can get them from me.

No warranty is given or implied that these parts are suitable for your application! (you would need to probably increase the fixed inductors inductance and may risk limited tuning correction)  Without doubt, the original parts as suggested by Thierry will be better and/or easier - at £2.50 each.

I almost always use Xicor 42IF106 transformers for my variable inductors - they are cheap and have tappings which can be swelected / connected to provide a huge range of variable inductances..

In fact, I now usually use two, and ommit fixed inductors altogether - Have one IFT wired for say about 100uH at mid slug, and another parrallel with it tapped / connected for about 1mH - The bigger inductor becomes fine tuning.

Why not take the original parts?

Its part # on the following website is EZ-1017 and can be ordered online even in small quantities:

http://www.jabdog.com/toko-ez.htm

Amazing.  I've been searching all day for these to only find "out of stock" results everywhere.

That's why I started looking for substitutions.  So, assuming I can order these, would you go with the values from the

original EM design (68 and 100 uH) or use the updated design values of 47uH (with additional fixed inductors in series)?

Thanks again.

The newer variant, 47uH variable in series with 47uH fixed (pitch) or 22uH fixed (volume) has proven to be

- easier to find

- easier to tune

- more frequency-stable

The newer variant, 47uH variable in series with 47uH fixed (pitch) or 22uH fixed (volume) has proven to be

- easier to find

- easier to tune

- more frequency-stable

Excellent. Thank you!