B. TEMPORARILY insert a 2 inch U-bolt through the turnbuckle plate and add two nuts so about 1/2
inch of the threads stick out. Insert this assembly through the top set of 2” U-bolt holes in the boom to
mast plate from the boom side and add two more nuts. Open the two turnbuckles up so just
a
thread
or two
from each end shows
inside
the body of the turnbuckle. Hook the turnbuckles into the holes at
the edge of the turnbuckle plate. Equalize the Dacron cord over the plate and cut it. Take two wraps
of the cord through the eye of the rear turnbuckle, PULL the cord as tight as possible and make the
knots as before. Repeat for the front cord section and turnbuckle. Cut off any excess over one foot
long and again seal and tape back to the main cord.
C. Now DISASSEMBLE the U-bolt from the boom to mast plate. Before installation, if possible, install
a short temporary mast, attach turnbuckle, and let the overhead guy system support the boom
overnight. The Dacron cord DOES NOT STRETCH UNDER THIS LOAD but it's weave will take a SET
and the boom may droop just a bit. If your boom droops again following final adjustments, check your
knots. They may be may be slipping.
D. After final installation of the antenna, the turnbuckle plate, installed loosely with a 2” U-bolt, is raised
up the mast. When the boom is straight the U-bolt is tightened. This should place the turnbuckle plate
4 to 6 feet above the boom. Do the final boom straightening with the turnbuckles and safety wire to
preserve adjustments.
18. Check ALL hardware for tightness. Check ALL element sections, especially tip sections, for correct
placement. Make any final adjustments to linear loading tension.
19. Attach the feedline section to the balun. Route it towards the boom to mast plate. Secure at
regular intervals with tape or nylon ties.
20. When mounting this antenna on a tower or mast with other antennas there may be interaction. In
general VHF and/ or UHF antennas mounted for HORIZONTAL POLARITY should be AT LEAST 40
inches above or below the antenna. Use good quality 50 Ohm coaxial cable to feed the antenna and
be sure your tower and rotator system can handle the wind loading and vertical weight of this antenna.
THIS COMPLETES ANTENNA ASSEMBLY
M
2
ANTENNA SYSTEMS, INC.
4402 N. SELLAND AVE.
FRESNO, CA 93722
(559) 432-8873 FAX (559) 432-3059
www.m2inc.com Email: [email protected]
40M3L ASSEMBLY MANUAL
