coil q pi

coil q pi

Antennas : End-Fed : End Fed Half Wave Antenna

• End Fed Half-Wave Antennas - An interesting article on end fed half-wave wire antennas with a couple of original experiments. Author illustrate the role of the QRP matchbox, and a 40/20 meter antenna with a center stub making it a large bandwidth antenna for 40 and 20. Includes also an 80/40 end fed with the typical coil to make it available on 80 merts band.
  [ Hits: 288 | Votes: 2 | Rating: 10 ]

• DIY Portable Car Whip Antenna - Being frequently away from home, the author owner of an Elecraft KX3 missed the opportunity to work /M. They devised a portable antenna solution, incorporating a coil and car body, enabling multi-band tuning. Despite its unconventional design, the antenna exhibits promising performance, resembling a vertical dipole.
  [ Hits: 54 | Votes: 0 | Rating: 0 ]

• Petlowany Antennas by K6NO - WorldRadio Article on Petlowany antennas base on this principle: if a length of wire is wound into a spiral-shaped coil and excited by a radio frequency current connected to the innermost portion of the coil, it will then, and only then, exhibit RF characteristics that closely approximate those of a resonant linear wire of the same length
  [ Hits: 3765 | Votes: 9 | Rating: 6.22 ]

• The Squid Pole Wire Antenna Re-visited - The author explores enhancing the performance of a 7-meter fiberglass squid pole wire antenna for amateur radio. The wire, resonant at 10MHz, poses impedance challenges on various bands. Experimenting with direct coax feed and UN-UN transformers, the LDG Z11-Pro2 auto-tuner is found effective but may show deceptive SWR readings. The author employs adjustable UN-UN ratios and introduces a custom "porcupine" coil to optimize the antenna's efficiency.
  [ Hits: 91 | Votes: 0 | Rating: 0 ]

• Inductor Calculator - Calculate inductance online, with the cylindrical Coil Inductor Design Equations Formulas Calculator
  [ Hits: 279 | Votes: 1 | Rating: 1 ]

• Grip Dip Oscillator - Originally eveloped by I1FLC, uses seven plug in coils covering 3.0 to 30Mhz in a Colpitts oscillator circuit.
  [ Hits: 667 | Votes: 1 | Rating: 10 ]