The MFJ-959C Receiver Antenna Tuner/Pre-Amplifier is a device designed to match your antenna to your receiver for optimal performance across a frequency range of 1.8 to 30 MHz. It ensures maximum signal power transfer by adjusting the antenna impedance to match that of the receiver. The tuner is especially useful when operating the antenna at frequencies other than its resonant frequencies, preventing signal loss due to impedance mismatch. Additionally, the MFJ-959C features a broadband transistor pre-amplifier to enhance signal strength, aiding older receivers with lower sensitivity and includes a 20 dB attenuator to manage strong signal overload issues.

For installation, simply connect an external power source of 9-18V DC to the rear panel power jack using a 2.1mm plug. Connect your receiver antenna input to one of the two output connectors labelled RECEIVER on the MFJ-959C. Attach your antenna to one of the ANTENNA connections on the device. To operate the MFJ-959C effectively, adjust the RCVR & ANT switches to select the desired receiver and antenna, then set the ON-OFF/BYPASS switch to ON. Fine-tune the ANTENNA and RECEIVER controls on the MFJ-959C for maximum signal reception, adjusting the inductor switch accordingly based on the frequency band.

During operation, set the TUNER/AMP-TUNER switch to TUNER to achieve an added gain of 20 dB for weak signal reception. Adjust the GAIN control for the desired signal level, noting that it is only functional when the TUNER/AMP-TUNER switch is in the TUNER/AMP position. If interference issues arise from nearby transmitters, switch the ATTN-ON/OFF to ATTN-ON to reduce unwanted signals. The MFJ-959C's tuner circuit helps minimize out-of-band interference, while the attenuator assists in managing signal overload problems, ensuring a clear and optimized reception experience.