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Anleitung Zusammenfassung
LPY2 Constructed on rugged FR-4 material, it requires no tuning and has no fragile antenna elements to break or twist! Covers the entire 900 to over 2,500 MHz frequency range. Why settle for any old antenna… this little baby “compresses” the signal into a powerful beam that is 4 times more powerful in the direction you desire! • Easy hookup to your Receiver or Transmitter • Small thin size with excellent broadband performance • Solid 6 dB gain from 900 to over 2,000 MHz! • VSWR less than 2:1 - great for transmitters up to 10 Watts! • Easily mounted by itself or makes a great feed for reflector dishes • Construction ideas for a wideband corner reflector and a ‘grid’ reflector dish are covered in the manual! • Very directional - ideal for point-to-point links RAMSEY TRANSMITTER KITS • FM100B Professional FM Stereo Transmitter • FM25B Synthesized Stereo FM Transmitter • MR6 Model Rocket Tracking Transmitter • TV6 Television Transmitter RAMSEY RECEIVER KITS • FR1 FM Broadcast Receiver • AR1 Aircraft Band Receiver • SR2 Shortwave Receiver • SC1 Shortwave Converter RAMSEY HOBBY KITS • SG7 Personal Speed Radar • SS70A Speech Scrambler • BS1 “Bullshooter” Digital Voice Storage Unit • AVS10 Automatic Sequential Video Switcher • WCT20 Cable Wizard Cable Tracer • LABC1 Lead Acid Battery Charger • ECG1 Electrocardiogram Heart Monitor • LC1 Inductance-Capacitance Meter RAMSEY AMATEUR RADIO KITS • DDF1 Doppler Direction Finder • HR Series HF All Mode Receivers • QRP Series HF CW Transmitters • CW7 CW Keyer • CPO3 Code Practice Oscillator • QRP Power Amplifiers RAMSEY MINI-KITS Many other kits are available for hobby, school, Scouts and just plain FUN. New kits are always under development. Write or call for our free Ramsey catalog. LPY2 INSTRUCTION MANUAL Ramsey Electronics publication No. MLPY2 Rev 1.1 First printing: August 2003 COPYRIGHT 2001 by Ramsey Electronics, Inc. 590 Fishers Station Drive, Victor, New York 14564. All rights reserved. No portion of this publication may be copied or duplicated without the written permission of Ramsey Electronics, Inc. Printed in the United States of America. LPY2 • 2 Ramsey Publication No. MLPY2 Price $5.00 KIT ASSEMBLY AND INSTRUCTION MANUAL FOR Logi LOG PERIODIC ANTENNA TABLE OF CONTENTS Introduction .................................4 Antenna Description ...................4 Standard Hook-up ......................5 Low Frequency Modification .......7 Building a Corner Reflector.........7 Building a Reflector Grid.............9 LPY2 Return Loss Plot ...............10 Return Loss vs. VSWR Chart .....10 Warranty .....................................11 RAMSEY ELECTRONICS, INC. 590 Fishers Station Drive Victor, New York 14564 Phone (585) 924-4560 Fax (585) 924-4555 LPY2 • 3 INTRODUCTION This small log periodic antenna, which we call the ‘Logi’, is ideal for getting the maximum performance out of any UHF to low frequency microwave wireless system. Its directional properties “compresses” the signal into a powerful beam that is 4 times more powerful in the desired direction. It is the ideal antenna for scanners, wireless LANs, and other wireless devices. Its directional properties make it exceptionally well suited for point-to-point links! The units small size and wide bandwidth also make it ideal for feeding reflector antennas, such as the easily constructed corner reflector or grid that are discussed later in the manual. ANTENNA DESCRIPTION To start with, what is a log periodic antenna? The seeming simplicity of the log periodic antenna belies the remarkable features of the design. It uses a common transmission line to alternately feed a group of 1/2 . dipoles that are strung together. These antennas together display excellent radiation qualities over a wide range of frequencies as well as relatively uniform input impedances and good VSWR characteristics. While the log periodic design has been around since the late 1950’s it has now been discovered to be at the cutting edge of antenna development. Looking at the physical layout of a log periodic antenna, one would see that it is comprised of multiple elements working together to provide a wide bandwidth of usable frequencies. The active (radiating or receiving radiation) portion of the antenna effectively shifts with frequency as one stage becomes ‘more resonant’ than the next. The lowest operating frequency is determined by the longest element and the highest operating frequency is set by the shortest element. As the frequency of the transmission (or reception) increases, the active region of the antenna shifts forward to the shorter 1/2 . dipole elements or vice versa as the frequency decreases. Obviously then the ‘secret’ for proper operation must lie in the length and spacing of the antenna elements. These and other factors must be carefully chosen to cover the desired frequency range for the antennas’ application. Instead of forcing you to figure out all the math and spend hours experimenting, the creation of ...