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RF Filtered DC Outlets
MFJ-1146
INSTRUCTION MANUAL
c
2020
MFJ Enterprises, Inc.
300 Industrial Park Rd. Starkville, MS 39759
P: (662) 323-5869
F: (662) 323-6551
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DISCLAIMER
The information in this manual is for user purposes only and is not
intended to supersede in f or m a ti o n contained in customer regulations,
technical manuals or documents, position a l hand books, or other official
publications. The c opy of this manual provided to the cu st o m er will
not be updated to reflect current data. Customers using this manual
should report errors or omissions, recommendati o n s for improvements,
or other comments to MFJ Enterprises, 300 Industrial Park Road,
Starkville, MS 39759.
Phone: (662) 323-5869
Fax: (662) 323-6551
Business hours: M-F 8:00 AM - 4:30 PM CST.
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Contents
1 THE MFJ-1146 1
1.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.3 CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4 INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 TECHNICAL ASSISTANCE 4
List of Figures
1 The MFJ-1146 RF Filtered DC OutletsTM. . . . . . . . . . . . . . . . . . . . . . . . 1
2 RFI Suppression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3 MFJ-1146 Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4 Station setup using the MFJ-1146 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
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MFJ-1146 RF Filtered DC Outlets Instruction & Technical Manual
1 THE MFJ-1146
1.1 INTRODUCTION
Wipe out power-line RFI with the MFJ-1146! Whether its a noisy switcher, power line, or engine,
up to -60 dBm of suppression keeps the hash out of your rig and away from your ears. Bring out
that weak low-band signal! This isnt a dainty filter either. The MFJ-1146 is rated for a total load
of 40 A at 13.8 VDC, but even if you blow a fuse, a series of LED indicators tells you instantly
which one is out. Worried about RFI getting in after the filters? The MFJ-1146 has you covered!
Properly grounded, the aluminum case will help keep RFI out. With four sets of Anderson
powerpoles and two sets of high-current binding posts, the MFJ-1146 is versatile enough for all of
your power needs.
Figure 1: The MFJ-1146 RF Filtered DC Outlets
TM
1.2 FEATURES
The primary feature of the MFJ-1146 is the RF filter. Figure 2 shows the results of measurements
made using an MFJ-5014 White Noise Generator and a spectrum analy ze r . The purple trace wi th
+ symbols represents the unfiltered (direct) output of the MFJ-5014 and serves as the baseline for
everything else. The green × symbols represent the filtered output of the MFJ-1146. Finally, the
blue +× symbols are the difference between the two, demonstrating the RFI suppression of the
MFJ-1146.
Table 1 shows the maximum RFI suppression by band. The RFI suppression is maximized on the
lowest bands where most RFI is encountered.
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MFJ-1146 RF Filtered DC Outlets Instruction & Technical Manual
Figure 2: RFI Suppression
Table 1: Suppression by Band
Band
Peak Suppression
160 m -60 dBm
80 m
60 m
40 m
30 m
20 m
17 m
15 m
12 m
10 m
6 m
-51 dBm
-46 dBm
-48 dBm
-24 dBm
-30 dBm
-20 dBm
-29 dBm
-15 dBm
-24 dBm
-25 dBm
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MFJ-1146 RF Filtered DC Outlets Instruction & Technical Manual
1.3 CONNECTIONS
Figure 3 shows the various connectors on the MFJ-1146. The total rated current across the entire
device is 40A.
Figure 3: MFJ-1146 Connections: 1.) Master Fuse, 2.) Channel Fuses, 3.) Power Poles, 4.) Binding
Posts, 5.) Safety & RFI Ground
1.) Master Fuse
2.) Channel Fuses
3.) 30A Anderson Power Poles
4.) Binding Posts
5.) Safety & RFI Ground
1.4 INSTALLATION
A simple station setup using the MFJ-1146 is shown in Figure 4. Place the MFJ-1146 between
your power supply and your radio while keeping the power leads going to the radio as short as
possible. You can attach multiple pieces of equipment to the MFJ-1146, but keep in min d that the
maximum current rating is 40A. Drawing more than that, even if t he individual channels are not
near their limits, will burn out the master fuse and require a replacement.
Figure 4: Station setup using the MFJ-1146
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MFJ-1146 RF Filtered DC Outlets Instruction & Technical Manual
2 TECHNICAL ASSISTANCE
If you have any problem with this unit first check the appropriate section of this manual. If the
manual does not reference your problem or reading the manual does not solve your problem, you
may call MFJ Technical Service at (662) 323-0549 or the MFJ Factory at (662) 323-5869. You will
be best helped if you have your unit, manual and all information on your station handy so you can
answer any questions the technicians may ask.
You can also send questions by mail to MFJ Enterprises, Inc., 300 Industrial Park Road,
Starkville, MS 39759; by Facsimile (FAX) to 662-323-6551; or by email to
[email protected]. Send a complete description of your problem, an explanation of
exactly how you are using your unit, and a complete description of your st at i on.
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USER NOTES
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