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TABLE OF CONTENTS CHAPTER I 1.1. 1.2. CHAPTER ll 2.1. PAGE ................... 1.1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.1 2.2. Unpacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fig.
CHAPTER I INTRODUCTION The typical modern transmitter or high-power amplifier has either a pi-network tank circuit or a broadband transformer output and will work into resistive loads of 50 to 75 ohms with Voltage Standing Wave Ratios (VSWR) of 2:l or less. This resistive load can only he achieved with a resonant antenna; thus, for multiband operation, multiple antennas are required. Space and cost considerations render this solution impractical for most amateurs.
1-2. SPECIFICATIONS. Frequency Coverage: Input Impedance: Load Impedance: Balanced Feedlines: Long-Wire Antennas: Power Capability: 1.8 to 30 MHz. Band Switch marked for 160, 80, 40, 20, 15, and 10 meter amateur bands; however, frequency coverage between amateur bands is possible by using the nearest band positions with a small reduction in matching capability. 50 ohms (resistive). 50 ohm coaxial with VSWR of 5:l or less a t any phase angle (3:l on 10 meters).
CHAPTER ll --INSTALLATION 3. REQUIREMENTS. Carefully remove the MN-2700 from the shipping carton and examine it for evidence of damage. If any damage is discovered, immediately notify the transportation company that delivered the unit. Be sure to keep the shipping carton and packing material for the transportation company to examine if there is a damage claim.
, Fig. 3-2 .
CHAPTER Ill OPERATION 3-1. FRONT PANEL CONTROLS. (Figure 1-1) VSWR SET Control: Varies the sensitivity of the VSWR sensing circuitry. Meter: Displays either forward power in watts or VSWR as selcted by meter switches. VSWR SET Switch: Used to calibrate the meter for VSWR measure ments. VSWR READ Switch: Causes meter to indicate VSWR. 200 and 2000 Watt Switches: Causes meter to indicate forward power, either 200 or 2000 watts full scale.
Multiband Antenna: A doublet antenna 135 feet long, center fed with open-wire feeders 67 feet long, can be matched using the accessory balun on 80 through 10 meters. The feeders make a good 160 meter vertical when connected together and to the BALILW (1:l or 4:l) terminal of the balun * I TO M A T c m m NETWORK 1 "lw~-r+I TO MATCHING BALILW (1:l or 4:l) 8010 METER CONFIGURATION (POS31BAL ON MN2700) , :.* .'.* 2 . -= .c.-,. " - :-- : ' A " . . -- <. -,< , .:s. .:< .~ <:*.-:.,* .
REACTIVE tuning control clockwise. Readjust the RESISTIVE tuning for a dip. If this dip is downscale from the first dip, you are tuning in the right direction, and should continue to alternately move the REACTIVE tuning control clockwise and tune the RESISTIVE tuning for a dip, until a minimum VSWR indication is obtained.
NOTES
CHAPTER IV MAINTENANCE The MN-2700 should be practically maintenance free, since it is a passive device. If either, or both, of the AA-119 diode rectifiers for the wattmeter are damaged, they must be replaced with the same type diodes. Substitution of other type diodes may seriously degrade the accuracy of the wattmeter. If any problems arise that cannot be corrected, either return the unit to your dealer, or write to our Service Department.
NOTES
