COIL DATA
Back
Those are data on the book; if you
can not use such wire or diameter, no problem.
Use what you can and build the first coil; take note of frequency range and build next
coil with more wire turns (or less to go up) or change diameter (i.e. doubling it or
reducing to a half); at the end fix turn using RF glue or PVC tape.
I suggest you to build coils as "square" as possible (diameter=height).
About wire, I have used copper wire caming from old broken-transformer or small driving
(used in walk-man).
Gamma MHZ | Length mm |
Diameter mm | Turns num. |
Inductance microH. |
3-4,5 | 30 | 21 | 75 | 60 |
4-5,5 | 25 | 21 | 62,5 | 48 |
5-7,5 | 19 | 17 | 47,5 | 24 |
7,5-11 | 10 | 17 | 25 | 10 |
10,5-16 | 11 | 11 | 27,5 | 5,5 |
15-22 | 6 | 11 | 15 | 2,5 |
20-31 | 6 | 9 | 15 | 1,80 |
My 30-60 (and up) MHZ coil is a simple copper "U".