MFJ-1756 Instruction Manual
6 Meter Ground Plane Antenna
9
BALUN
In order to prevent unwanted radiation from the feedline, we suggest installing a balun at
the feedpoint. This need not be an elaborate or expensive addition--you can make a
simple and effective choke-type balun using the feedline itself. Below are three examples
of how to do this:
1. Form a 5-turn coil (about 3 to 6" in diameter) of coax just below the feedpoint using
about 6' of cable. Tape the coils together tightly with electrical tape and secure them
to the mast.
2. Install a 5" total length of 43 mix ferrite core on the feedline at the feedpoint. Be sure
to secure your feedline to the mast with electrical tape to provide stress relief at the
feedpoint.
3. Using a metallic mast, from the feedpoint keep the coax 3 to 4" from the mast for 50".
Use an insulator (PVC pipe) if necessary. Below the 50" air spaced length tape the
coax to the mast and keep the coax taped against the mast for at least three feet.
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 your problem is not solved by reading
the manual, you may call
MFJ Technical Service
at
601-323-0549
or the
MFJ Factory
at
601-323-5869
. 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 601-323-6551; 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
station.
