KW-Grade Antenna Trap Designer
Power & Voltage Rating
-- V
Peak RF Potential
--
1. Coaxial Capacitor
--
Capacitance (pF)
2. Inductor Coil
--
Inductance (µH)
3. Performance Results
-- MHz
-- Ω
--
-- Ω
Must Match XL
Trap Design Guide & Tips
The "Sweet Spot" (250Ω - 450Ω)
Aim for a reactance in this range. It provides the best balance between trap efficiency (blocking power) and bandwidth. Too low, and the trap is "leaky." Too high, and the voltages might arc.
The L/C Ratio
Increasing Inductance (more turns) and decreasing Capacitance (less overlap) raises the reactance. This makes the trap "sharper" but more sensitive to weather.
Power & Voltage
At 100 Watts, a trap can see 1kV-2kV. At 1.5kW, this can exceed 5kV. Use Teflon for QRO. PVC is okay for low power but can melt at high duty cycles (FT8/CW) as it absorbs RF heat.
Physical Build
Seal the ends of the tubes to prevent insects or water from entering. Water inside the tubes will drastically change the capacitance and shift your frequency significantly.
Engineering Formulas
Capacitance:
C (pF) = (55.63 * k * L_meters) / ln(D/d)
Inductance:
L (µH) = (d² * n²) / (457d + 1016l)
Resonance:
f (MHz) = 159.155 / √(L * C)