MAGNUM 257 OPERATING MANUAL
Copyright © 1999 by Magnum International. All rights reserved.
TABLE OF CONTENTS Introduction ......................................................................................................... 4 Limited Warranty ................................................................................................. 5 Installation ...................................................................................................... 6 - 7 Front Panel Controls .................................................................................... 8 - 10 Other Features ......
INTRODUCTION Congratulations on your purchase of a Magnum 257 10 meter FM/SSB/AM transceiver. The 257 is designed to provide years of enjoyment and trouble-free service. There are many features and functions designed into this transceiver. To ensure that your investment is enjoyed to its fullest extent, please take a few moments and thoroughly read this manual. The Magnum 257 is a microprocessor controlled, user programmable radio combining high RF performance with a user-friendly environment.
LIMITED WARRANTY Magnum International warrants this product to be free of defects for a period of one (1) year from the original date of purchase. This warranty is non-transferable. This limited warranty is subject to repair or replacement of defective components only. This warranty is void if the radio has been tampered with or misused.
INSTALLATION 1. Contents Unpack and inspect your Magnum 257 for missing or damaged components. Your 257 includes the following items: Quantity 1 1 1 1 1 Connect the positive (+) red wire of the DC power cord to a positive 13.8 volt source at the vehicle fuse block. If connecting to the fuse block, it is recommended that a switched power source is used so that the power to the transceiver is disconnected when the vehicle is off.
VSWR exceeds 1.8 to 1. This will stress the output stage and could destroy the RF transistors; this type of misuse and failure is not covered under warranty. Measure the VSWR at the center of the operating band. Tune the antenna (according to the manufacturer’s tuning instructions) so that the VSWR is as close to 1.1 to 1 at the center of the operating band. Next, measure the VSWR at the lowest and highest frequency of the transceiver.
16 17 12 13 3 1 2 5 4 14 7 6 15 9 8 10 11 FRONT PANEL CONTROLS 1. MICROPHONE INPUT A 6-pin, lock ring type, microphone connector is used. Microphone wiring is as follows: Pin 1 : Microphone Audio Pin 2 : Receive Pin 3 : Transmit Pin 4 : Down (Up w/ 22K Ohm Resistor) Pin 5 : Ground Pin 6 : +13.8 VDC 4. STEP \ NB \ 1 STEP: Tuning Step. The STEP control selects frequency resolution in either 1 kHz, 10 kHz or 100 kHz steps. Press the STEP button, one of the digits will flash on and off.
RPT: Repeater Access Tone. Most repeaters require an 88.5 Hz tone burst to access. To activate the 88.5 Hz tone burst, press the FUNC control and then press the RPT button. RPT will appear on the LCD indicating that the tone burst will now automatically be transmitted whenever the PTT is pressed. To deactivate, repeat the same process. To stop scanning, press the SCAN button, or momentarily press the PTT button on the microphone (scanning will stop without transmitting). 4: Memory Channel 4.
OTHER FEATURES 10. CLAR \ FUNC CLAR: Clarifier. The clarifier shifts both the TX and RX frequency 1.5 kHz each side of the center frequency. This is necessary for tuning to an SSB signal. Rotate the clarifier control clockwise or counterclockwise to tune an SSB signal. 1. PROGRAMMING TONE This tone sounds each time the CPU is being programmed. It is helpful, in the beginning so you can be sure the command has been entered.
GENERAL SPECIFICATIONS Frequency Coverage Antenna Impedance Frequency Control Frequency Accuracy Power Requirement Current Consumption Dimensions Weight : : : : : : : : Transmit and Receive ...................................... 28.000 to 29.699 MHz 50 ohm, unbalanced Digital Phase-Lock Loop (PLL) Synthesizer Better than +10 ppm from 0 - 40 0C after 15 min. warm up 12 - 13.8 V DC, negative ground 6 amps maximum 6 x 2 x 9.5 in (W x H x D) 2.
MAGNUM INTERNATIONAL A Division of RF Limited PO Box 445 • Issaquah WA 98027 Telephone 425-558-9592 • Facsimile 425-558-9704 Technical Support Only 1-877-MAGNUM-9 (1-877-624-6869) http://www.MagnumRadio.com E-Mail info@MagnumRadio.
