Ja bym w ogóle nie stosował rdzenia. Jeśli przyjąć że impedancja baluna powinna być >10x większa niż linii to wychodzi 500 omów. Podstawiając pod matematykę cewka powinna mieć 2uH lub więcej. 10 zwojów kabla z odstępem 15mm na wodkanie 100mm średnicy da ci 3uH
Polecam ten kalkulator, jest bardzo dobry
QOIL™ — https://hamwaves.com/qoil/ — v20181217
Coil design 2020-07-18 19:26
INPUT
mean diameter of the coil D = 100 mm
number of turns N = 5
length of the coil ℓ, = 80 mm
wire or tubing diameter d = 5 mm
design frequency f = 50 MHz
The (plating) material is annealed copper.
INTERMEDIATE RESULTS
winding pitch p = 16.00 mm
physical conductor length ℓ,_w_phys = 1572.8 mm
effective pitch angle ψ, = 2.93°
RESULTS
Effective equivalent circuit
effective series inductance @ design frequency L_eff_s = 3.421 μ,H
effective series reactance @ design frequency X_eff_s = 1074.8 Ω,
effective series AC resistance @ design frequency R_eff_s = 0.186 Ω,
effective unloaded quality factor @ design frequency Q_eff = 5791
Lumped circuit equivalent
f-independent series inductance, geometrical formula L_s = 2.072 μ,H
series AC resistance @ design frequency R_s = 0.068 Ω,
parallel stray capacitance @ design frequency C_p = 1.9 pF
Self-resonant frequency f_res = 60.342 MHz
