INSTRUCTION MANUAL
CAUTION: Read All Instruction Before Operating Equipment
MFJ ENTERPRISES, INC.
P.O. BOX 494, MISSISSIPPI STATE, MS 39762, USA
925- 0037D- 752D- REV 1
COPYRIG HT 2010 MFJ ENTERPRISES, INC.
MFJ SIGNAL ENHANCER II
Model MFJ-752D
Page 1: ...UAL CAUTION Read All Instruction Before Operating Equipment MFJ ENTERPRISES INC P O BOX 494 MISSISSIPPI STATE MS 39762 USA 925 0037D 752D REV 1 COPYRIGHT 2010 MFJ ENTERPRISES INC MFJ SIGNAL ENHANCER II Model MFJ 752D ...
Page 2: ...ceiver or receiver to the MFJ 752D Use an RCA phono plug to connect to the filter input There are two inputs on the MFJ 752D allowing connection to two receivers for greater convenience The input is selected by the push button switch on the back of the MFJ 752D 3 Connect a speaker to the filter using shielded wire with a RCA phono plug at the filter speaker output For best results use a 4 to 16 oh...
Page 3: ...he NOTCH filter is approximately 70 dB Notch frequency is adjustable from approximately 300 Hz to 3000 Hz The primary notch filter can be set to the NOTCH mode by setting the Function Selector to NOTCH Set SELECTIVITY control to the 9 o clock position Adjust FREQUENCY control to remove the CW signal or heterodyne Increase SELECTIVITY clockwise to narrow the bandwidth of the notch Readjust FREQUENC...
Page 4: ...eration It can be used to obtain very narrow bandwidths with good skirt selectivity and little ringing when the primary filter is in the peak mode or to limit the bandwidth when the primary filter is in the NOTCH LOW PASS or HIGH PASS mode NOTE When using both filters in the PEAK mode with narrow bandwidths the best skirt selectivity and least attenuation will be obtained by setting both the auxil...
Page 5: ... and turn the SELECTIVITY and FREQUENCY controls to minimum counter clockwise 2 With high selectivity the filter may have a tendency to ring in peak and lowpass modes If this occurs decrease the selectivity 3 Due to the very high internal filter gains in the LOW PASS mode with maximum selectivity and frequency the filter may OSCILLATE If this occurs reduce SELECTIVITY and FREQUENCY controls until ...
Page 6: ... 1V p p and adjust generator frequency control s for a null minimum amplitude Null should occur at about 3000 Hz 4 Switch Primary Function Selector to PEAK 5 Increase Primary SELECTIVITY control to maximum 6 Adjust R319 10K High Tracking trimmer for maximum amplitude 7 Set generator frequency to 500 Hz 8 Set primary SELECTIVITY control to 3 o clock 9 Set primary filter to NOTCH and adjust primary ...
Page 7: ...6 MFJ 752D Schematic Diagram ...
Page 8: ...is warranty is NOT void for owners who attempt to repair defective units Technical consultation is available by calling 662 323 5869 5 This warranty does not apply to kits sold by or manufactured by MFJ Enterprises Inc 6 Wired and tested PC board products are covered by this warranty provided only the wired and tested PC board product is returned Wired and tested PC boards installed in the owner s...
