New secondary for VTTC:
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    d =   7,5 cm
    h =  29,0 cm (32,2 cm PP form, ratio 3,87:1)
    N = 850
wired =   0,34 mm
wirel = 200 m
  RDC =  42 ohm
  RAC =  54 ohm

computed f0:   643,8 kHz
computed L:     12,355 mH
computed C:      4,946 pF
computed XL: 49979 ohm
estimated Q0:   65

measured f0: 601 kHz
measured Q0: 188 (according to f-char Q=f0/B3)
measured RDC: 44 ohm
measured L:   12,24 mH

Primary:
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    d = 11,0 cm
    h =  8,3 cm
    N = 18,33
wired =  2,26 mm
wirel =  6,34 m
  RDC =  0,027 ohm
  RAC =  0,181 ohm

computed L: 30,2 uH (gives C = 2,33 nF)
Xl = Xc = 114 ohm (gives Rp at resonance = 2846 ohm @ Q = 25)
GU-81 calculated internal impedance Ri = 5000 ohm
computed coupling: k = 0,42
computed f1 = 503 kHz (3,35 nF), f2 = 787 kHz (1,35 nF)

Feedback:
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    d = 11,0 cm
    h =  2,1 cm
   N1 = 10
   N2 = 15
   N3 = 20
wired =  0,4 mm