OZ9AEC

 
  • Increase font size
  • Default font size
  • Decrease font size
Home Butternut HF2V Tuning the 40m Coil

Tuning the 40m Coil

Print PDF

With the current settings on 30m (26cm 2.5 turns shorted), fc on 40 shifted to 7.188 MHz - even with 8 turns shorted. Moving the shorting strap to 7 turns, fc shifts to 6.988 MHz. With 7.5 turns shorted fc = 7.039 MHz.

 L40=26cm 8t fc=7.166M

L40=26cm 7t fc=6.988ML40=26cm 7t5  fc=6.988M
HF2V SWR on 40
 HF2V SWR on 40 HF2V SWR on 40

Unfortunately, this influenced the 30 meter band as well shifting the resonance down, but still SWR below 1.5 within 10.100-10.150 MHz. No influence on 15.

FYI, an index of all SWR graphs can be found here.