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The Shrunken Quad antenna is a unique design that offers full-sized performance on the 10m and 15m bands while incorporating linear loading via a trap for operation on the 20m band. This design allows for effective communication in the HF spectrum, making it suitable for both casual operators and serious DXers. The quad configuration provides excellent gain and directivity, which is beneficial for contesting and long-distance contacts. Constructing the Shrunken Quad involves careful attention to dimensions and materials to ensure optimal performance. The antenna's compact nature makes it an excellent choice for limited space situations, allowing operators to enjoy the benefits of a quad without the need for extensive real estate. This project is ideal for amateur radio enthusiasts looking to enhance their station's capabilities with a versatile and efficient antenna system.

This project details the design and construction of a Spider Quad antenna for HF bands (20m, 17m, 15m, 12m, and 10m). The boomless structure optimizes driver and reflector spacing, enhancing performance. Tuning and impedance matching were refined using antenna analyzers and a 1:2 balun. Final tests confirmed excellent SWR and gain, making this an efficient solution for top performance DXing.

A multi-band trapped dipole antenna working on 20, 40, 75 and 160 meters band. This project implement a 20 meter trap unadilla reyco KW-20, 40 meter trap Unadilla Reyco KW-40 and a HI-Q 1:1 balun feed.

A detailed guide presents a simple 2-element quad antenna for 2m, offering ease of construction, portability, and efficient performance across the 144-148 MHz band. The design allows quick disassembly for storage and features adjustable polarization, making it ideal for various applications, including transmitter hunting and SSB operations.

Chavdar Levkov, LZ1AQ, presents an experimental comparison of small wideband magnetic loops, building on his previous work on wideband active small magnetic loop antennas. His research focuses on increasing loop sensitivity by maximizing the short-circuit current, which is directly tied to the "loop factor" M = A/L, where A is the equivalent loop area and L is its inductance. Levkov's methodology involves reducing inductance and increasing area through parallel or coplanar crossed (CC) configurations, comparing these designs against a reference single quad loop of 1 m2 area. Experimental verification included testing three distinct loop types: a simple quad loop, two coplanar crossed (CC) loops, and eight parallel loops, all designed to have a total geometric area of 1 m2. Measurements were conducted at 1.8, 3.5, 7, and 10 MHz using a small transmitter 270 meters away, with a Perseus direct sampling receiver for precise signal level assessment. The results consistently showed that CC loops, particularly Loop 5 (two CC circular loops with 1.44 m2 total area), yielded significantly higher currents, up to 9.1 dB over the reference loop at 3.5 MHz, validating M as a reliable predictor of loop sensitivity. Numerical simulations using MMANA further corroborated the experimental findings, demonstrating an almost perfect correlation between the calculated M factor and the induced loop current for 15 different loop models. Levkov concludes that CC loops offer superior sensitivity for a given loop area, while parallel loops are advantageous for minimizing physical volume. Practical recommendations suggest using loops with an M factor greater than 0.5 uA/pT for quiet rural environments, and he provides a spreadsheet tool, WLoop_calc.xls, to aid in optimizing loop configurations for specific operational needs.