MFJ-1903 Tilt-Mount Instruction Sheet
Introduction:
The MFJ-1903 Universal Vertical Tilt Base is designed to let you
assemble and adjust your vertical antenna on the ground, then walk it up into its
vertical operating position with safety and minimal effort. Made from rugged 1/8-
inch aluminum plate, the MFJ-1903 features a pattern of pre-punched mounting
holes that accept most common U-bolt sizes for antenna masts up to 2-1/4
inches in diameter. In addition, you can bolt many popular verticals using
insulated base brackets directly to the MFJ-1903 swing plate without using U-
bolts (Hy-Gain AV18VS, AV18AVQII, AV14AVQ, AV12 AVQ, DX-88, etc). The
MFJ-1903 also provides spare bolt holes for connecting a ground rod or a radial
system.
Installation Instructions:
Before assembling your MFJ-1903, please check the
parts list on page-2 to confirm that all listed items are included.
[ ] Find the two 2-1/4” U-bolts and 3/8” hardware. Attach the
base bracket
(wider
of the two mounting plates) securely to your base support.
[ ] Find two 5/16” bolts and hardware. Attach the
tilt bracket
(narrower plate) to
the base bracket’s pivot point, as shown below. Do not over-tighten -- the tilt
bracket should remain moveable.
[ ] Using your antenna’s mounting hardware, install the support mast (or
insulated bracket) onto the face of the
tilt bracket
.
[ ] After the antenna has been raised vertically into position, lock the
tilt bracket
to the
base bracket
using the remaining two 5/8” bolts and hardware. Check and
re-tighten all hardware to ensure everything is tight.
Antenna
U-bolt
U-bolt
Lock Bolt (x2)
5/16"
Pivot Bolt (x2)
5/16"
Tilt Bracket
Base Bracket
Base Pipe
