• Element length: 53.4 cm each (quarter wavelength at 137 MHz)
• Angle: 120° between elements (not 180°)
• Material: Any stiff wire, coat hanger, or copper rod
• Orientation: Lay flat or tilt 30° toward expected pass direction
• Polarization: The 120° angle gives partial RHCP match to satellite signal
• Connection: Solder elements to coax center + shield, connect to SDR via SMA

Best starter antenna. Good enough for clear NOAA images with a direct overhead pass.

• Elements: Two crossed dipoles, each 53.4 cm per side (4 elements total)
• Angle: 90° between the two dipole pairs
• Phasing: Feed dipole 2 with a 90° delay (quarter-wave coax section ~37 cm of RG-58)
• Reflector: Place ~52 cm below elements (ground plane or wire grid)
• Polarization: Circular (RHCP) — matches satellite transmission

Better than V-dipole. The reflector rejects ground noise and the RHCP phasing matches the satellite signal.

• Design: Two bifilar helical loops, offset 90°
• Material: Copper pipe (10mm), copper wire, or coax outer shield
• Total height: ~46 cm (for 137 MHz)
• Loop dimensions: Use a QFH calculator for exact bending measurements
• Polarization: True RHCP omnidirectional — ideal for overhead satellite passes
• Gain pattern: Hemispherical upward coverage, rejects ground interference

Gold standard for weather satellite reception. No tracking needed — covers the whole sky.

• Location: OUTDOORS with clear sky view is critical. Roof/balcony/open field.
• Height: Higher is better but not critical — clear horizon line matters more
• Antenna up: Point the antenna straight UP (zenith) for best overhead coverage
• Avoid: Metal roofs, power lines, buildings blocking the sky
• Coax length: Keep short (<10m). Signal loss at 137 MHz is ~3 dB per 10m of RG-58
• LNA: Mount at the antenna feed point, NOT at the SDR end. Recommended: Nooelec SAWbird+ NOAA (137 MHz filtered LNA, ~$30)
• Bias-T: Enable the Bias-T checkbox above if your LNA is powered via the coax from the SDR