M2 Antenna Systems 25M4, Assembly Manual

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25M4 ASSEMBLY MANUAL
NOTE: A cup of zinc paste (PENETROX, NOALOX, or equivalent) has been provided to enhance the quality of
all the electrical joints and make assembly and disassembly easier. Apply a thin coat wherever two pieces of
aluminum come in contact.
REFER TO THE DIMENSION SHEET FIRST. YOU MAY BE ABLE TO ASSEMBLE THE ANTENNA
REFERRING TO THE WRITEEN INSTRUCTIONS ONLY AS A GUIDE.
1. BOOM ASSEMBLY: Note the different boom sections and the approximate position of each element. ALSO
NOTE THAT TWO BOOM SECTIONS HAVE LARGE EYEBOLT MOUNTING HOLES. Slide the INNER TWO
2-1/2” RING CLAMPS into their approximate positions on the appropriate boom sections. Note the FIRST
DIRECTOR ring clamp mounts between two boom coupling bolts in the third boom section. Spread the ring
clamp fingers with a flat blade screwdriver to ease movement on the boom. Loosely add a 1/4-20 x 1” bolt and
locknut to fingers of all clamps. Add 1/4-20 x 3” bolts and locknuts to each joint and tighten securely. Add the
eyebolts and secure with 5/16-18 nuts and lockwashers.
NOTE: THE FOLLOWING OPERATIONS SHOULD BE DONE WITH THE BOOM AT WAIST HEIGHT.
2. Push two 1/4-20 x 2” bolts through the small holes in the 2” x 5” BALUN MOUNTING PLATE. Now feed
these bolts down through the inner two holes of the 7/8 x 30” fiberglass rod. Mount this assembly onto the
SECOND ring clamp holes (DRIVEN ELEMENT) and add the locknuts to the underside of the ring clamp.
Tighten securely. Then push on a 2” diameter white POLYETHYLENE RING on each side. These rings form a
long path to prevent water and residue induced arcing. ALIGN the ring clamp so it’s long grooved top is
perpendicular to the EYE BOLT HOLE just to the rear in the first section and tighten the ring clamp.
3. Select the two 1-1/4” x 60” SOE (Swaged One End) element sections with 9/32 holes in the butts. There will
also be two sleeve sections in the butts. Slide them onto the 7/8” diameter fiberglass rod. Align the holes in all
the sleeves and add the 1/4-20 x 2-1/2” bolts so the threaded ends are up. Add a pair of 3/8 clamp blocks to
each side and then add a locknut finger tight to each side (The balun leads will attach to these studs later in the
assembly).
4. Add a 1” x 60” SOE element section to each side. Align the holes and secure with 8-32 x 1-1/2” screws and
locknuts. Tighten the screws alternately until each joint is secure and no movement is detected in either joint.
5. Slide two more 1-1/4” element sections and slide the butts over the 1-1/8” x 30” sleeves. Align the holes and
drop in two 1/4-20 x 2” bolts. Set the assembly over the rear ring clamp. Add the two locknuts and tighten
securely. It is the center section of the REFLECTOR element. Now add two more 1” x 60” tubes and secure
these to the inner sections with 8-32 x 1-1/2” screws and locknuts. Tighten the screws alternately until each
joint is secure and no movement is detected in either joint.
6. Pair up the remaining 1-1/4” element sections and slide the butts over the 1-1/8” x 30” sleeves. Align the
holes and mount to the ring clamps using more 1/4-20 x 2” bolts and locknuts and secure.
7. Assemble the rest of the element halves using the 8-32 screws and locknuts as described on the ELEMET
ASSEMBLY SHEET and the DIMENSION SHEET. Tighten each joint securely by alternating back and forth
between the two screws at each joint until no movement is noted. BE SURE TO PAIR UP the 3/8” tip sections
and get them in the correct locations.