MFJ-1789 Rotatable Mini-Dipole
Instruction Manual
8
9)
Using six hose clamps (three on each radiator), clamp the fiberglass insulators so as to support the
16” and 55” threaded rods. Position the insulators as shown in Figure 4.
10)
Mount the four stubs (two on each side) by threading a 10-32 x 3/8" nut 1/2" near the end of the
threads. Add a second nut and lock-washer to sandwich the bracket between the two nuts,
leaving no more than ¼” of threaded rod exposed beyond the aluminum bracket. See Figure 4.
IMPORTANT: Use a 5/16” nut driver to tighten the capacitance spokes in place. Tighten
by hand only. A high torque electric screwdriver will shear the screws.
11)
Install the 6-32 screws in all rings of both loading coil assemblies, loosely holding them in place with
their associated nuts. Position the screws so the threaded ends of the screws are pointed outward
towards the two ends of each loading coil assembly as shown in Figure 5. .
NOTE: You can ease your tuning effort by pre-marking the outer ends of the spokes prior
to installation. You can do this by placing 1”, 2”, and 3” marks on one end of each
spoke using a black permanent marker pen. Then subdivide these marked
sections into ¼” segments using a red permanent marker pen.
NOTE: Install the spokes through the rings until they come in contact with the fiberglass
rod. This will give you about 1/4” of spoke available to slide back out should you
trim too much off a spoke during tuning.
12)
Install the spokes as shown in the diagram below. A few extra 27 “ long spokes have been included
just in case you cut some too short.
Summary of Contents for 1789
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