What is an RDF?

In the days before GPS, sailors made use of Radio Directions Finding receivers as navigational aids.

RDF radios generally are specialised radio receivers for long wave regularity reception, varying from 150 kHz to 520 kHz and furnished with fundamental direction finders. The 150 to 520 kHz portion of the range at once was occupied with lots of marine beacons, all transferring their call signs constantly in slow CW for recognition and area. Some transferred weather forecast utilising AM voice. RDF receiver contains a large ferrite antenna that is rotatable atop, a compass recommendation, and signal strength meter was made use to focus on a specific aquatic radio beacon.

Old RDF Companies

RDFs were created for numerous decades by producers such as Ray Jefferson, Gladding, Pearce-Simpson, Raytheon, as well as also Heath kit and Hammarlund, names acquainted to SWLS as well as hams. Many were mobile, batteries power them, as well as contain telescopic antennas built-in them for different bands that were consisted of such as the CB band, perhaps the “new” VHF aquatic band (156.05-162.025 MHz), FM BCB (88-108 MHz), as well as even the old Marine band (2-4 MHz coverage). A lot of versions included the AM program band, which probably functioned as the ship’s primary resource of home entertainment in previous days.

With the Development of Technology

One can use RDFs by AM DXers as auxiliary receivers or long wave enthusiasts as a result of their ability to void out undesirable AM signals on the program band using the big rotatable ferrite antenna.

Nowadays, you can also find drone mounted RDF, so that the drone never loses its direction. The technology is growing, and with-it GPS service is also performing their tasks. Now, the sailors also take help from the GPS to guide their way, but still a secondary system in hand is always handy. Therefore, RDFs are used as the secondary system while navigating in the sea or ocean or in the sky.