An automatically tuned 7-30MHz mobile antenna
- This is a base-loaded vertical antenna that mounts on the car's roof. The loading coil is designed as a variable inductor, with a three-legged chariot that travels up and down inside the coil, with grooved brass wheels running on the coil turns, and driven by a slotted rotor tube.
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
The Alabama Historical Radio Society
- The alabama historical radio society - come visit our website and museum where we have a large collection of antique radios. our club does coil winding, has a large library, and a wealth of knowledge in our members.
- Distributor of aluminum and a manufacturer of finished aluminum products. Pierce Aluminum offers a diverse inventory and distributes a complete line of sheets, coils, plates, bars, structural shapes, tubes, pipes and extrusions in the most varied alloys and sizes possible
- Inductance calculation for single layer, air-wounded coils and helixes up to about 800 MHz. Inductance calculations accuracy is around 1%. Also, coils with maximum Q for given inductance, resonant RF chokes, PI and T resistive attenuators calculations are provided. Skin effects, radiation losses and other minor side effects are not accounted in maksimum Q factor coils calculations. Program assumes using copper (Cu) enameled or silver (Ag) plated wire. Program is writen bilingual in English and Serbian by YU1AW