MAGNUM 257
OPERATING MANUAL
Page 1: ...MAGNUM 257 OPERATING MANUAL ...
Page 2: ...Copyright 1999 by Magnum International All rights reserved ...
Page 3: ...TABLE OF CONTENTS Introduction 4 Limited Warranty 5 Installation 6 7 Front Panel Controls 8 10 Other Features 10 Specifications 11 Contact Information 12 3 ...
Page 4: ...eration Some of the features of the 257 are an advanced design liquid crystal display that provides the operator with a full visual account of the transceivers operating status automatic frequency scanning from either the front panel or microphone memory storage of your favorite frequencies and modes programmable frequency resolution of either 1 kHz 10 kHz or 100 kHz and split frequency operation ...
Page 5: ...pt within 15 days from the purchase date If the warranty registration form and copy of your sales receipt are not received the radio is not covered under warranty Please fill out the enclosed warranty registration form and send it along with a copy of your sales receipt to Magnum International PO Box 445 Issaquah WA 98027 Registering your 257 with Magnum provides several benefits 1 Validates your ...
Page 6: ...f 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 This will eliminate the possibility of the transceiver drain ing the vehicle s battery Connect the negative black wire to a metal part of the vehicle s frame or chassis ground Make sure that this is a good ground connection The 257 power...
Page 7: ...ible problems 1 Make sure that the antenna is installed properly and grounded 2 Check all coaxial cable and connectors for defects and poor routing 3 If testing a vehicle installation make sure that all vehicle doors are closed when testing 4 Do not test near or around large metal objects or buildings 7 Ignition Noise In certain vehicle installations electrical noise or inter ference may be presen...
Page 8: ...the FUNC 10 control the FUNC prompt will be displayed in upper left hand corner of LCD Push the control again to deactivate the function control 2 3 4 10 1 5 6 7 8 9 11 16 17 12 13 15 14 4 STEP NB 1 STEP Tuning Step The STEP control selects fre quency resolution in either 1 kHz 10 kHz or 100 kHz steps Press the STEP button one of the digits will flash on and off Press the STEP button again to chan...
Page 9: ...gnal is no longer detected To stop scanning press the SCAN button or momen tarily press the PTT button on the microphone scan ning will stop without transmitting SHIFT Shift Offset Used for programming offsets to operate repeater networks The 257 can transmit and receive on different frequencies To program the offset press the FUNC button and hold down the SHIFT button for 3 or more seconds Three ...
Page 10: ...Variable RF Output Power Rotate clockwise to increase RF output power Rotate counterclockwise to decrease RF output power Variable RF output power allows low power transmit ting for QRP operation in compliance with the FCC re quest for reduced signal strength during periods when propagation levels are high 16 Push To Talk Switch Press and hold the switch to transmit TX will appear on the LCD scree...
Page 11: ...uppression More than 40 dB below peak output power Unwanted Sideband More than 50 dB below peak output 1 kHz tone FM Deviation 2 kHz maximum Audio Response More than 30dB below peak output Frequency Response 400 to 2800 Hz Microphone Impedance ECM 600 to 1K ohms RECEIVER SPECIFICATIONS Circuit Type Dual Conversion Superheterodyne Intermediate Frequencies 1st IF SSB IF 10 695 MHz 2nd IF 455 kHz Sen...
Page 12: ...NATIONAL 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 com ...
