Carl
05-10-1999, 10:35 AM
>hi carl--
>the pictorial on the web site shows a long solenoid
>type structure---the coils made here are generally
>on a plexiglass form with easy measure of dimentions.
>by a resistance measure can get close on the number
>of turns---by resonance with cap of known value
>(though Q is a little wide sometimes) carefull
>peaking---can attain inductance value--by experiment.
>then by plugging in values into formula mentioned,the
>delta was not too far different---so close that just
>tweeking the frequency a little from what was called
>peaked--now difference is on the other side....
>should be interesting to see you come up with---
I read through the article and found nothing suggesting a length limit so maybe the formula is valid for short coils like your measurements suggest. Probably needs a slight "fudge factor" added.
>question--you make coil winder--mine all by hand--
>tedious but no production requirements...running out
>of magnet wire----not like old days 1lb/4.95
The only source I can find right now is Mouser, 1lb/$12 or 8lb/$75. Have you ever tried wire wrapping wire instead? Thicker insulation should give lower interwinding capacitance. More expensive, tho.
- Carl
>the pictorial on the web site shows a long solenoid
>type structure---the coils made here are generally
>on a plexiglass form with easy measure of dimentions.
>by a resistance measure can get close on the number
>of turns---by resonance with cap of known value
>(though Q is a little wide sometimes) carefull
>peaking---can attain inductance value--by experiment.
>then by plugging in values into formula mentioned,the
>delta was not too far different---so close that just
>tweeking the frequency a little from what was called
>peaked--now difference is on the other side....
>should be interesting to see you come up with---
I read through the article and found nothing suggesting a length limit so maybe the formula is valid for short coils like your measurements suggest. Probably needs a slight "fudge factor" added.
>question--you make coil winder--mine all by hand--
>tedious but no production requirements...running out
>of magnet wire----not like old days 1lb/4.95
The only source I can find right now is Mouser, 1lb/$12 or 8lb/$75. Have you ever tried wire wrapping wire instead? Thicker insulation should give lower interwinding capacitance. More expensive, tho.
- Carl