Pembangkit Sinyal ELT pada Frekuensi 121,5 MHz

Rustamaji Rustamaji(1), Kania Sawitri(2), Ray Hapri Sitepu(3),


(1) Jurusan Teknik Elektro Institut Teknologi Nasional Bandung
(2) Jurusan Teknik Elektro Institut Teknologi Nasional
(3) Jurusan Teknik Elektro Institut Teknologi Nasional

Abstract

An ELT is a beacon indicating the location of distress or crash of aircraft on land or sea. The ELT is placed in an airplane, which is a transmitter with low transmit power and an antenna. The ELT transmitter has been widely used for flights at the frequency of 121.5 MHz (civilian) and 243 MHz (military). The purpose of this study is to produce ELT signal generators at the 121.5 MHz frequency, with low-cost devices that meet specifications for civil aviation. In this research has been produced a design of an ELT signal generator at the frequency of 121.5 MHz, consist of a crystal oscillator, a sawtooth generator, a VCO, and an amplitude modulator. Based on the measurement and test results, the sawtooth generator generated a sawtooth signal at the frequency of 1.8 to 3.6 Hz, the VCO generated a sinusoidal signal at the frequency of 316 to 366 Hz, the RF generator generated a sinusoidal at the frequency of 121.505 MHz. The ELT signal generator was able to generate AM signals at the minimum amplitude deviation of 100 mVpp to maximum one of 156 mVpp, the modulation index (m) of 21.875%, and the frequency of 121.505 MHz. The results of this study are ELT signal generators at the frequencies of 121.5 MHz that are in accordance with specifications for civil aviation.

Keywords

sawtooth generator; VCO; crystal oscillator; amplitude modulator; ELT

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References

Radio Stations and Systems – Article 1.93. definition: emergency position-indicating radio beacon station, ITU Radio Regulations, Section IV, 2012.

Handbook on Radio Frequency Spectrum Requirements for Civil Aviation - including Statement of Approved ICAO Policies, ICAO Fifth Edition, 2009.

CFR Part 91 Emergency Locator Transmitters. Final Rule 2000, Departement of Transportation Federal Aviation Administration.

R. J. Wallace and T. P. Hubbard, “Effect of 406 MHz ELTs and COSPAS SARSAT Cessation of 121.5 MHz ELT Monitoring on Search and Rescue Duration for General Aviation Aircraft Accidents in the Contiguous United States,†International Journal of Aviation, Aeronautics, and Aerospace, vol. 1, no. 2, p. 2, 2014.

“EBC-502HM Instruction and Maintenance Manual,†Emergency Beacon Corporation, 15 River Street, New Rochelle, NY 10801, 2016.

H. C. Gabler and C. J. Molnar, Development of an Enhanced Emergency Locator Transmitter for General Aviation, Final Report, Rowan University Department of Mechanical Engineering Glassboro, NJ 08028, September 2006.

K. Babulu and R. S. Vinay, “VLSI Design Approach for Emergency Locator Transmitter (ELT) signal of 406 MHz with Enhanced Ground Proximity Warning System Receiver,†International Journal of Computer Science and Information Technologies, vol. 2, no. 5, pp. 1958-1961, 2011.

A. Gunderson, C. Byers, and D. Klumpar, “Emergency Locator Signal Detection and Geolocation Small Satellit Constellation Feasibility study,†in 25th Annual AIAA/USU Conference on Small Satellites, pp. 1-11, Agt. 2011.

C. R. Carter, E. Casas, and T. Chung, “Emergency Locator Transmitter (ELT) signal models for SARSAT,†Canadian Electrical Engineering Journal, vol. 11, no. 2, pp. 43-49, 1986.

B. A. Kalaria, C. G. Nayak, and N. K. Shrivastava, “Designing a Web Based Module for SAR to Ensure Data Security Using JAVA,†International Journal of Computer Science and Mobile Computing, vol. 3, no. 4, pp. 297-306, 2014.

B. A. Srihen, J. P. Yonnet, and M. Benslama, “Closed Approach of a Decoder Mobile for the 406 MHz Distress Beacon,†Advances in Science, Technology and Engineering Systems Journal, vol. 3, no. 6, pp. 243-246, 2018.

I. Joo, J. H. Lee, Y. M. Lee, C. S. Sin, S. U. Lee, and J. Kim, ‘‘Development and Performance Analysis of The Second Generation 406 MHz EPIRB,’’ in International Conference (IEEE) 4th Advanced Satellite Mobile Systems, pp. 333-336, 26-28 Aug. 2008, Bologna, Italy.

J. M. M. Heredia, Z. Garcia, and J. L. M. Jimenez, “Development of an Emergency Radio Beacon for Small Unmanned Aerial Vehicles,†IEEE Access, vol. 6, pp.21570-21581, 2018.

“Crystal Clock Specification Part No. + Packaging: LFSPXO059450Reel,†IQD frequency products, 3 Oct. 2016.

Circuits, pp. 54 and 200, Netherlands: Elektor Publisher. Ltd, 1979.

S. Soi, “Design and Characterization of a 3rd Order Low-Pass Butterworth Filter,†International Journal of Science and Research (IJSR), vol. 3, no. 7, pp. 1-3, July 2014.

W. Yelan, “Design of an AM Modulator using MC 1496,†Journal of Beijing Institute of Light Industry, vol. 23, no. 2, pp. 46-48, 2005.

NRSC-G101 AM Modulation-Dependent Carrier Level (MDCL) Usage Guideline, NRSC, April 2013.

Radio Regulations Articles, ITU Edition of 2012.

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