Auto-Coaxial Switch Controller for Redundancy in FM Broadcasting Transmitter

Authors

  • Adisak Pattanajakr Khon Kaen University, Thailand
  • Puripong Suthisopapan Khon Kaen University, Thailand
  • Richard G. Baltes International Broadcasting Bureau, Thailand
  • Apirat Siritaratiwat King Mongkut’s Institute of Technology, Ladkrabang, Thailand
  • Anan Kruesubthaworn Khon Kaen University, Thailand
  • Rujipas Sumranbumrung Rajamangala University of Technology Isan Khonkaen Campus, Thailand

Keywords:

FM Broadcasting Transmitter, Program Logic Controller, Auto Coaxial Switch

Abstract

This paper presents the design and implementation of a Programmable Logic Controller (PLC)-based automatic coaxial switch controller for redundant Frequency Modulation (FM) broadcasting transmitters. The proposed system facilitates autonomous switching between the main transmitter (Tx1) and the backup transmitter (Tx2), ensuring seamless connection to the antenna and uninterrupted broadcast service. Experimental results indicate that the output power (Pout) during normal operation (signal from Tx1) and after switching (signal from Tx2) are comparable, measured at 939.61 W and 944.06 W, respectively. Furthermore, the switching process requires no more than 30 seconds per event, guaranteeing continuous FM broadcasting throughout the year, with the total switching time representing less than 1% of the annual transmission duration. Consequently, the proposed automated controller operates independently without the need for a computer, master clock, or human intervention.

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Published

2026-07-01

How to Cite

Pattanajakr, A., Suthisopapan, P., Baltes, R., Siritaratiwat, A., Kruesubthaworn, A., & Sumranbumrung, R. (2026). Auto-Coaxial Switch Controller for Redundancy in FM Broadcasting Transmitter. Engineering Access, 12(2), 326–334. retrieved from https://ph02.tci-thaijo.org/index.php/mijet/article/view/261461

Issue

Vol. 12 No. 2 (2026): July-December

Section

Research Papers

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