Prototype of Short Wave Compact Receiving Antenna Using Tuning Circuit with Servo Motor

Abstract

 A 30 mm × 45 mm size amplifier integrated printed circuit board antenna (also called a probe) developed by Roelof Bakker was manufactured to receive a LF band of 136 kHz, which was recently approved for use in amateur radio.

 It has been verified that this antenna is effective not only in the LF band but also in the MF/HF band (300kHz to 30 MHz) and part of the VHF band (30 MHz to 150 MHz).

 Although MF/HF band is not the main use in the ship communication, it still occupies an important role for safe navigation of ships, like reception of emergency radio signal transmission, SSB telephone, NBDP (character communication), FAX reception, DSC reception, NAVTEX reception and radio broadcasting reception,.

 In general, MF/HF antennas are larger than other frequency bands antenna. Therefore, as these antennas become smaller, there are many points that can be useful, such as maintainability, aesthetic appearance, and suppression of obstacles during shipboard operation.

 This time, I tried to construct a system with an LC resonance circuit filter and automatic tuning by a personal computer with this antenna with many noises in MF/HF use.

 I report the effectiveness of this prototype antenna as a commercial radio reception used in a ship.