Here is a simple antenna design that is effective from 3 to 22 MHz. Based on a resonant magnetic loop, it has high transducer gain (high sensitivity), and also very good directionality. You can build it cheaply from junk box parts. The basic design is a …

Direction finding (DF), or radio direction finding (RDF), is the use of radio waves to determine the direction to a radio source. The source may be a cooperating radio transmitter or may be an inadvertant source, a naturally-occurring radio source, or an illicit or enemy system.

Loop antennas are commonly used for RDF on HF. A Bunny Hunting Primer is an introduction to transmitter hunting. Longer quad beams extends the common 2-element designs. The Long Baseline Interferometer is a method of taking very accurate bearings with two simple antennas.

Loop Antennas A simple antenna for RDF work is a small loop tuned to resonance with a capacitor. Several factors must be considered in the design of an RDF loop. The loop must be small compared with the wave-length. In a single-turn loop, the conductor should be less than 0.08 wavelength long. For 28 MHz, this

Not only will this antenna function well as an RDF unit, it will also tune well for transmit on 2 meters. The SWR is adjusted by tweaking the distance between the driven elements. Mine is set at 1 inch for a 1.3:1 match.

Single K9AY Loop Characteristics • 2.5 dB RDF Increase Over Vertical • Broadband (Flat to 20 MHz) • Gain -25 dBi (<< Vertical) • Directional Antenna - End-fire (In plane of the loop) opposite termination - Similar to a cardiod pattern - Reduced response in rear direction

In virtually all installations without clearly dominant direction or directions of noise arrival, RDF (receiving directivity factor) accurately predicts receiving antenna performance. RDF (receiving directivity) will be an almost perfect indicator of what you …

This design is essentially two half delta loops that are interconnected to create a single antenna, with one transformer and one load resistor. The improvement in RDF over a single flag of similar size is about 2.5 dB. The Double Half-Delta Loop RX Antenna. Dimensions: Wire a and d are 7.5 m long with the lower ends at 1.5 m above ground.

The RDF TD-C358 is specified for frequencies between 200 kHz and 16 MHz. It comes along with a Crossed-Loop Antenna of 0.8 m dia., 30 m of 7-core coax connecting cable (not to be shortened), an

2018年2月2日 · A loop antenna is a radio antenna consisting of a loop or coil of wire, tubing, or other electrical conductor usually fed by a balanced source or feeding a balanced load. Within this physical description there are two distinct antenna types. The . large self-resonant loop antenna has a circumference close to one wavelength