Magnum M-257 User Manual

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Frequency Coverage 25.165 - 29.699 MHz
RF Power Output 30W SSB / 9W AM/ 30W FM
Dual Finals on Heat Sink
Modes AM, FM, USB, LSB
Microprocessor Controlled
5 memories
Last Channel Recall
Frequency Scan
10khz or 1khz steps
Variable RF Output Power
Variable Mic Gain
Built in Speech Processor
5 Digit LCD Frequency Display
Scanning Microphone
Night Illuminated Display
Surface Mount Technology throughout
Dimensions 2(H) x 6(W) x 9.5(D) in

Magnum M-257 Specifications

General

Brand	Magnum
Model	M-257
Category	Transceiver
Language	English

Summary

Product Overview and Specifications

General Specifications

Frequency Coverage

Specifies the operational frequency range of the transceiver, including an expanded mode.

Antenna Impedance

Details the required antenna impedance for optimal performance.

Frequency Control

Explains the method used for frequency control and its accuracy.

Power Requirement

Outlines the voltage and polarity needed for the device.

Dimensions

Provides the physical size of the transceiver.

Transmitter and Receiver Specifications

Transmitter Power Output

Details the RF power output for different modes (SSB, AM, FM).

Transmitter Tuning Steps

Specifies the increments for frequency tuning.

Receiver Sensitivity

Indicates the minimum signal level required for reception.

Receiver Selectivity

Defines the receiver's ability to distinguish signals.

Receiver Clarifier Range

Specifies the adjustment range for fine-tuning received signals.

Frequency Modification Procedures

Frequency Range Configurations

Details jumper settings for different frequency coverage modes.

Tune-Up and Power Tweaks

Guides for adjusting RF power and modulation for optimal performance.

Front Panel Controls Overview

Microphone Input and Mic Gain

Details pin assignments for the microphone and mic gain adjustment.

RF Gain and Step Button

Explains RF gain control and the function of the step/NB button.

LCR, RPT, CALL, and MODE Buttons

Describes functions for last channel recall, repeater use, call frequency, and mode selection.

Scan, Shift, Freq, and Clarifier Controls

Details scan, shift, frequency selection, and clarifier functions.

Volume, Squelch, and Power Controls

Explains volume, squelch, power controls, and variable RF output power.

Push to Talk and Microphone Controls

Details the PTT switch and microphone UP/DN controls.

Other Features and Functions

Programming Tone and Memory Backup

Describes the programming tone confirmation and memory channel backup system.