Log Periodic Antenna Projects
Antenna projects and designs for radio amateurs.
Log periodic antennas are a popular choice for hams needing wideband coverage across multiple HF or VHF/UHF bands. These arrays offer consistent gain and a stable SWR across their operating range, making them ideal for operators who frequent different frequencies without needing to switch antennas or use an antenna tuner. Their design allows for a single antenna to replace several monoband Yagis, simplifying antenna projects and tower installations.
This category provides numerous resources for designing and building log periodic dipole arrays (LPDAs). Operators can find detailed plans and mechanical drawings, such as the K8CU Log Periodic Antenna, for constructing arrays covering bands from 10 to 30 MHz or even 50 MHz. There are also design calculators and spreadsheets to help determine element dimensions and spacing, along with articles discussing critical aspects like balun placement to avoid RFI and ensure proper operation.
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A project by G3SYC of a log periodic antenna for 6 meters band -
Modified version of the Telerana antenna which was orginially featured in the July 1979 issue of QST. The array is suspended within a framework made of fiberglass poles emanating from a central hub with the ends tied together with light weight rope around the perimeter. 10-15-20-30-40 meter band coverage -
Overview, summary, tutorial about the log periodic antenna or aerial used for wideband RF antenna applications -
Log periodic antenna design excel sheet file download, in italian. -
Some antenna manufacturers place baluns at the incorrect location in LPDA arrays, or tell you to route the cable incorrectly. This can cause substantial RFI and all sorts of weird problems like RF into house wiring. -
10 to 20 meters band log-periodic antenna project with SWR Plots, boom lenght and element spacing. -
Plans, photos, electrical and mechanical design for this HF Log periodic antenna. -
calculates the dimensions and spacings of the elements needed to build a log periodic antenna, given tao, sigma and the lower and upper cutoff frequencies. -
This QST article describes the electrical and mechanical design process for two LPs that cover the HF bands from 10-30 MHz -
A detailed drawing of a VHF UHF Log periodic antenna by VA2PHI -
A homebrew four elements log periodic antenna for HF bands -
An article explaining features and characteristics of amateur radio log periodic antennas -
Online calculator for Logarithmic Periodic Dipole Antenna LPDA -
Description and online calculator for Log Periodic Dipole Arrays LPDA are directional antennas featuring a relatively constant characteristics across a wide frequency range. -
This project introduces the Loggi, a hybrid antenna merging the wide frequency coverage of log-periodic dipole arrays (LPDA) with the high gain and front-to-back ratio (F/B) of Yagi antennas. Traditional LPDAs span broad frequencies with moderate gain and low VSWR, while Yagis provide high gain and F/B over narrow bands. By analyzing high-Tau LPDA designs, it was found they could nearly match the gain of VHF/UHF Yagis while maintaining excellent patterns, F/B, and front-to-rear ratios (F/R). Optimizing specific elements for target frequencies (e.g., 144.1 MHz) led to the Loggi, which uniquely features all driven elements without passive directors or reflectors. This design effectively functions as a narrowband optimized LPDA, with front elements acting like Yagi directors and rear elements like Yagi reflectors, thus enhancing gain and directional characteristics while retaining broad frequency versatility. -
17-Element Very High Frequency/Ultra High Frequency Log Period Dipole Array