2014年6月17日火曜日

qrp-gaijin small transmitting loop calculator


Loop geometry


Loop conductor geometry





Tuning capacitor parameters










Possible future parameters




Tuning range
Graph parameters



Disclaimer

No claim of accuracy is made for this calculator. Do not use this calculator for any purpose except entertainment. Refer to the references and perform your own calculations to see if they agree with this calculator's output.


Notes on usage of this calculator

This calculator allows calculation and visualisation of loss components in a small transmitting loop. Unlike other small loop calculators, this loop calculator has a number of unusual features:
  • Support for multi-turn loops (but see notes below)
  • Choice of copper, aluminum, or custom conductor material
  • Support for flat (rectangular cross-section) conductors using W9CF's analytic formulas for RF resistance and self-impedance (see references) 
  • Support for braided conductor loss using a fixed multiplier between 4 and 16 to represent increased losses through wire-to-wire pressure connections in braid
  • Inclusion of capacitor loss including fixed, dielectric, and metal losses, as per G3RBJ's model (see references); two capacitor models pre-defined, with custom parameters allowed
  • Inclusion of connecting wire loss (connecting capacitor and loop)
  • Visualisation of all loss components in both normalised and absolute-value graphs.
Note that for multi-turn loops, the calculator does not include losses due to turn-to-turn proximity effect or turn-to-turn capacitance (circulating currents). The efficiency estimates for multi-turn loops will thus be optimistic.

The validity of W9CF's analytic formulas for rectangular cross-section conductors as used in small transmitting loops, especially multi-turn loops, is not clear.

Ground losses are not included.


References