[HomeBrew] Coil linearity?

[Doug Laidlaw]

Inductance varies direcrly as the square of the turns and inversely as th=
e=20
length - approximately.  So your suggestion should get somewhere close at=
 HF,=20
but there are other considerations as low as 1 uH.  Better to use Bob's=20
spreadsheet.

Doug VK3KDI

On Mon, 30 Dec 2002 10:49 am, kwylow zinjanthropus wrote:
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>
> All:
> Just wanted to know this. Is coil inductance linear with respect to tur=
ns?
> For example, if I wound a coil evenly at 10 turns and it is valued at 1=
 uH,
> can I assume that each turn is 0.1 H and that winding 5 more turns woul=
d
> make the coil value 1.5 uH? I'm trying to wind a 30 meter coil for that
> AC-1 replica that I just built. The 40 meter coil is about 15.5 tpi and=
 the
> plate of the 6V6 dips at about 10 % of the plate cap value and the ante=
nna
> load cap doesn't affect the power out that much into a dummy load (50
> ohms). I guesstimated the plate cap value to be about 36.5 uuF (10% of =
365
> uuf) and reverse engineered the coil to determine a value of the 40 met=
er
> coil (wound with #22 magnet wire at 15.5 tpi). Of course, I used the
> formula freq=3D1/(2*pi*SQRT(L*C)). Calculating the final turns per inch=
 for a
> coil with the plate cap at 25% (or 91.25 uuF) yielded a coil at 7 tpi #=
22
> magnet wire resonating at 10.115 MHz. Let me know your thoughts on this=
 and
> thanks. Cal, N6KYR.
>
>
>
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