The 145 MHz Twin Delta Loop Antenna is one of the most efficient and easy-to-build antennas for the 2-meter amateur radio band. With its excellent gain, wide radiation pattern, and stable SWR, this antenna has become a top choice among VHF enthusiasts and home-brew antenna builders. In this guide, we will explore the design, dimensions, feeding method, and performance characteristics of a well-optimized Twin Delta Loop antenna for 145 MHz.
Finding a single antenna that handles multiple HF bands without a mountain of complicated traps is a challenge. While many hams reach for a standard dipole, the Off-Center Fed (OCF) design offers a much smarter way to stay active on several bands. This specific design Multiband OCF Dipole, originally developed and tested by Rick Littlefield (W1BQT), serves as a reliable workhorse for the 40, 20, 10, and 6-meter bands.
By shifting the feed point, we tap into a “magic spot” where the antenna’s impedance stays relatively consistent across harmonically related frequencies. This makes it a perfect match for the standard 50-ohm coax found in most shacks today.
A double dipole antenna remains one of the most practical choices for amateur radio operators who want reliable HF coverage without using a complicated antenna system. The design shown here uses a 31-meter overall length and supports operation across multiple amateur bands from 80 meters through 10 meters.
This antenna is simple, low cost, and effective. It works well for operators who need strong regional coverage on lower bands and reasonable DX performance on higher frequencies.
NVIS is much more than a curiosity or a fallback for those who do not have tall towers. It is a strategic operating method designed to fill the gap between ground wave communications and long-distance, low-angle communications.
In amateur radio, the skip zone (also known as the “dead zone”) is the region where communication is impossible because the transmitter’s signal cannot reach the receiver through any propagation mode.
In conventional HF configurations, the “skip zone” can produce a communication void ranging from 30 to 300 miles. Ironically, in emergency situations or for regional coordination, it is in the skip zone that your most critical contacts are. NVIS eliminates this problem by radiating energy upwards, bouncing it back from the ionosphere, and bathing it back down like a floodlight.
