Dodgy plans to make Archimedean spiral antenna for RTLSDR software defined radio receiver. Made of two equal lengths of coaxial cable seems to be the easiest circularly polarized antenna to make that will cover a broad range of the rtlsdr dongles E4000 tuners
OSX/Mac and Windows versions of SdrDx. Supports RFSPACE, FunCube Pro, Andrus MK1.5, AFEDRI, FunCube Pro Plus, Peaberry, RTL sticks (RTL supported under OS X only, via this OS X RTL server) and Softrock SDR receivers.
The N0QBH QRSS project page, a couple of projects using available kits for improved frequency and timing stability. A configurable DDS VFO 100mW transmitter with LCD display and a modified Hans Sommers 40m 100mW transmitter
These simple instructions will guide you through the operations required to calculate antenna system VSWR: preparation, connecting the wattmeter, taking the readings, calculating VSWR, and disconnecting the wattmeter.
Second floor grounding, Field Day Vertical Antenna by KN5L, Ground Systems as a Factor in Antenna Efficiency, IC-705 English Brochure, W9GF GAP TITAN DX Antenna Installation, Win4IcomSuite ICOM Radio Control Software, Challenger DX Antenna Review by NK7Z, Win4YaesuSuite - Yaesu Radio Control, Balun_cmr Calculate common-mode impedance, Online Helical Coil Calculator