Tube Amps / Music Electronics
For current discussions, please visit Music Electronics Forum. New: view Recent Searches.
New: visit Schematic Hell!
The sunn still shines online!

Listen to great tunes streaming live right now!

ampage archive

Vintage threads from the first ten years

Search for:  Mode:  

Strange problem with coils

4/9/2003 2:50 PM
Albert Kreuzer
Strange problem with coils
Just built Art Harrison's 126 tube theremin using self-wound inductors (air core, 5/16" diameter, 3/4" long, 800 turns).  
They measure exactly 1mH on my L-meter, the same as the small cheap ferrite core inductors I used for testing.  
What I don't understand:  
With the ferrite coils, I get the desired frequencies, with the air-core ones only half of it!  
Theoretically, this would mean they have four times the inductivity of the ferrite coils, but why do they read the same on my meter?  
Any kind of info or help appreciated!  

Don Symes What frequency does your L-meter me... -- 4/10/2003 12:06 AM