MFJ-9412 Instruction Manual
12-Meter SSB Transceiver
3
The MFJ-9412 monoband transceiver is designed especially for fixed or portable radio
communication via the twelve-meter amateur band. Energy-efficient analog circuitry and
syllabic speech processing deliver superior on-air performance while conserving valuable
energy. The MFJ-9412 uses a single-conversion mixing format and a low-noise
heterodyne VFO for enhanced weak-signal performance. The transmitter stages provide
tuned inter-stage coupling and a built-in 7-element lowpass filter to suppress interference
at TV and FM-broadcast entertainment frequencies. Other features include a sharp
communication-grade crystal IF filter, built-in heavy-duty speaker, fully-analog
mechanical S-meter, optional semi-break-in CW module, and intuitive controls.
Typical Specifications
Receiver Section:
Frequency Coverage: .....................................24.890-24.990 MHz
Mode: .............................................................USB
Receiver Type: ...............................................Single-conversion Superhet
Frequency Control: ........................................6-MHz VFO mixed to 34.9 MHz
IF Frequency: .................................................10 MHz
IF Selectivity:.................................................-6 dB @ 2.4 KHz
AGC: ..............................................................Audio-derived, 70-dB dynamic
range
Sensitivity: ......................................................15 uV for 12-dB S/N
Audio: ............................................................500 mW into 8 Ohms at 10% THD
Average Receive Current Drain:....................60-mA with S-meter lamp disabled
Transmitter Section:
Typical RF Power Output: .............................12 Watts PEP
Mode ..............................................................USB
VSWR Tolerance: ..........................................3:1 VSWR maximum
Peak TX Current: ...........................................3.0 Amps
Speech Enhancement: ....................................RF-compression, syllabic rate
Spurious Attenuation: ....................................-60 dBc typical
Mic Input: ......................................................600-Ohm dynamic
*CW operation possible within the 24.89 to 24.930 range with an optional CW adapter board.
