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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
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Related Manuals for Magnum M-257
Summary of Contents for Magnum M-257
- Page 1 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...
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Page 2: General Specifications
GENERAL SPECIFICATIONS: Frequency Coverage 28.000 to 29.699 Frequency Coverage 25.165 – 29.699 Expanded Antenna Impedance 50 ohm unbalanced Digital Phase-Lock Loop(PLL)Frequency Accuracy Better than +10ppm from Frequency Control 0-40° C after 15 min warm up. 10.5 - 15VDC ~ Negative Ground Power Requirement Current Consumption 6.0 amps maximum... -
Page 3: Frequency Modification
FREQUENCY MODIFICATION: Step #1: Make sure Magnum 257 is turned off and disconnected from power source! Step #2: Take off speaker-side cabinet. Step #3: Find the CPU Reset Board located near the Front panel of the radio located behind the Microphone Connector. - Page 4 In the Expanded mode, the frequency range is divided into Bands of Channels each. The Bands are shown on LCD display by letters (A through J) - Band E is regular 40 channel CB. To switch bands, press the CALL button (do not hold down for 3 seconds). In the Expanded mode, either the frequency or channel can be displayed on the LCD.
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Page 5: Front Panel Controls
FRONT PANEL CONTROLS #1 ~ MICROPHONE INPUT Pin #1 ~ Microphone Audio Pin #2 ~ Receive Pin #3 ~ Transmit Pin #4 ~ Down(Up w/22K Ohm Resistor) Pin #5 ~ Ground Pin #6 ~ +13.8VDC #2 ~ MIC GAIN #3 ~ RF GAIN #4 ~ STEP BUTTON \ NB \ 1 STEP Controls tuning steps in either 1 kHz, 10 kHz, or 100 kHz as well as activates the Noise Blanker circuitry when used with the FUNCTION button. - Page 6 #9 ~ M. SAVE \ M. LOAD Memory Save and Memory Load (Recall) #10 ~ CLAR \ FUNC Clarifier shifts both the TX and RX frequency 1.5 kHz each side of the center frequency. #11 ~ FREQ Rotate clockwise or counterclockwise to select desired frequency. #12 ~ OFF \ VOLUME Turns the power to the radio on and off.