Kenwood R-5000 Instruction Manual

Also see for R-5000: Service manual Instruction manual Service manual Instruction manual Service manual

Contents

• Doublet AntennaThis type of antenna is suitable for reception of a specificband.The relation between the overall length "L" and the tunedfrequency is:7-2. ANTENNA AND GROUNDING7-2-1. AntennaThe following describes various antenna types and theirinstallation.• Long Wire AntennaThis is the simplest antenna, using about 30 – 100 feet(10 – 30 m) of wire installed between poles, trees orother convenient supports. The antenna wire should beheavy 8 gauge vinyl insulated, stranded wire or 4-gaugecopper wire or copperweld. This type of antenna must beinstalled horizontally to a length of 60 feet (20 m) or more,and be positioned as high as possible. Note that it shouldbe as far away as possible from AC power lines, buildings,trees and other objects.Fig. 7-1 shows an inverted L antenna. Other antennatypes such as sloping, vertical, etc. are also possible.A long-wire antenna, when installed in an open area, is sui-table for all-band operation.• Inverted V AntennaThis is a modified doublet antenna, designed to be in-stalled on a single pole or support. The characteristics ofthis antenna are almost the same as those of a doublet.The overall length "L" is a little more than that of a doublet,and is computed thus:• Multiband AntennaThis antenna uses more than one doublet for multiband re-ception. The overall length "L" is the same as that of thedoublet. If the lengths L1, L2 and L3 are cut for 7 MHz, 14MHz and 28 MHz, then L1 is tuned to 21 MHz (3 x 7 MHz),permitting reception on 4 amateur bands 7 – 28 MHz.When used only for reception, this antenna will cover the6 – 30 MHz SW bands. (See Fig. 7-4)This antenna is directional. Signal strength is maximumwhen the antenna is at a right-angle (broad-side) to the de-sired signal and the frequency for which the antenna iscut. It must be used with a 75-ohm coaxial feeder. (SeeFig. 7-2)• Trap Vertical AntennaAntennas designed exclusively for BCL are available com-mercially, or may be built yourself. Antennas designed forHAM band (3.5 . 28 MHz or 7 – 14 MHz) operation willprovide satisfactory broadcast reception for stations nearthe SW bands. Antennas of this type are most suitable forthe listener who does not have enough space for installa-tion of a doublet or long-wire antenna. (See Fig. 7-5)32