ASSEMBLY AND INSTALLATION
INSTRUCTIONS
20 / 17 / 15 / 12 / 10 Meter Beam Antenna
MA5B
951485 (5/99)
MA5B
WARNING
THIS ANTENNA IS AN ELECTRICAL CONDUCTOR. CONTACT WITH POWER LINES CAN RESULT IN DEATH, OR SERIOUS
INJURY. DO NOT INSTALL THIS ANTENNA WHERE THERE IS ANY POSSIBILITY OF CONTACT WITH OR HIGH VOLTAGE ARCOVER FROM POWER CABLES OR SERVICE DROPS TO BUILDINGS. THE ANTENNA, SUPPORTING MAST AND/OR TOWER
MUST NOT BE CLOSE TO ANY POWER LINES DURING INSTALLATION, REMOVAL OR IN THE EVENT PART OF THE SYSTEM
SHOULD ACCIDENTALLY FALL. FOLLOW THE GUIDELINES FOR ANTENNA INSTALLATIONS RECOMMENDED BY THE U.S.
CONSUMER PRODUCT SAFETY COMMISSION AND LISTED IN THE ENCLOSED PAMPHLET.
Your Cushcraft MA5B Yagi is designed and manufactured to give trouble free service. This antenna will perform as specified if the instructions
and suggestions in this manual are followed and care is used in the assembly and installation. When checking the components received in
your antenna package use the parts listed beside each diagram. There is a master parts list on page 2. If you are unable to locate any tube
or component, check the inside of all tubing. IMPORTANT: Save the weight label from the outside of the carton. Each antenna is weighed at
the factory to verify the parts count. If you claim a missing part, you will be asked for the weight verification label.
Plan your installation carefully. If you use volunteer helpers be sure that they are qualified to assist you. Make certain that everyone involved
understands that you are the boss and that they must follow your instructions. If you have any doubts at all, employ a professional antenna
installation company to install your antenna.
LOCATION
PLANNING
Location of the antenna is very important. Surrounding objects such as trees, power lines, other antennas, etc. will seriously reduce efficiency.
To minimize the effects of surrounding objects, mount the antenna as high and in the clear as possible. If metal guy wires are used, they should
be broken with strain insulators. EXTREME CARE MUST BE USED FOR YOUR SAFETY. YOU MUST INSURE THAT WHILE THE MA5B IS
IN OPERATION NEITHER PEOPLE OR PETS CAN COME IN CONTACT WITH ANY PORTION OF YOUR ANTENNA. DEADLY VOLTAGES
AND CURRENTS MAY EXIST. ALSO, SINCE THE EFFECTS OF EXPOSURE TO RF FIELDS ARE NOT FULLY UNDERSTOOD, LONG
TERM EXPOSURE TO INTENSE RF FIELDS IS NOT RECOMMENDED. THERE IS A WARNING STICKER WHICH MUST BE ATTACHED
TO THE BOOM AS SHOWN IN FIGURE I.
MOUNTING
The mast mount bracket will accommodate up to a 2" (5.1 cm) mast. A 1-1/2" OD (3.8 cm) or larger heavy wall tubing mast should be used. A
good heavy duty antenna rotator will provide the best service and longest life. Often it is desirable to mount several antennas on one mast.
To keep possible interaction to a minimum, place your antennas as far apart as you can.
SYSTEM GROUNDING
Direct grounding of the antenna, mast and tower is very important. This serves as protection from lightning strikes and static buildup, and from
high voltage which is present in the radio equipment connected to the antenna. A good electrical connection should be made to one or more
ground rods (or other extensive ground system) directly at the base of the tower or mast, using at least #10AWG ground wire and noncorrosive
hardware. For details and safety standards, consult the National Electrical Code. You should also use a coaxial lightning arrester. Cushcraft
offers several different models, such as LAC-1, LAC-2 and the LAC-4 series.
ASSEMBLY
Assemble your antenna by following the directions and illustrations in steps 1 through 6. After the antenna is completely assembled, verify
dimensions and element spacings for accuracy. Then, return to the section below for final tuning.
Set the element lengths for the portion of the band you want to operate on using Chart A and Figure 2. Your MA5B is now ready for use.
You may check the VSWR in order to confirm assembly was done properly. The easiest place to check the antenna is likely to be in its final
mounting configuration. Orient the antenna such that it is pointing straight up. The back of the antenna should be at least 2 feet (.6 m) off the
ground.
Run the coax cable from your transmitter to the area in which the antenna is to be tested. The length of this cable or your feedline is not critical.
Connect a good quality VSWR bridge to the end of this cable. Connect a short length of cable [10 ft. (305 cm) or less] from the VSWR bridge
to the antenna under test. Set the transmitter to your center operating frequency and measure the VSWR while taking care not to effect the
measurement with your body. A VSWR of 2:1 or less is satisfactory and will not degrade the performance. If the VSWR is greater than 2:1,
check all dimensions and connectors.
TUNING PROCEDURE
Page 1
MA5B
MASTER PARTS LIST
KEY PART# DESCRIPTION QTY
MT3 MT3 21/28 MHz TRAP ASSEMBLY 2
MT2 MT2 24.9 MHz TRAP ASSEMBLY 2
MT1 MT1 21/28 MHz TRAP ASSEMBLY 2
MN MN5B MA5B MATCHING NETWORK 1
EF MA5BEF MA5B ELEMENT EF (1-1/8” x 84”) 1
EE MA5BEE MA5B ELEMENT EE (7/8” x 12”) 2
ED MA5BED MA5B ELEMENT ED (1-1/8” x 46”) 2
EC MA5BEC MA5B ELEMENT EC (7/8” x 7”) 4
EB MA5BEB MA5B ELEMENT EB (1-7/8” x 36” SW) 6
EA MA5BEA MA5B ELEMENT EA (1-1/8” x 34”) 2
BB MA5BBB MA5B BOOM BB (1-5/8” x 24”) 1
BA MA5BBA MA5B BOOM BA (1-1/2” x 44”) 2
116 240116 SILICONE PACKAGE 1
115 050115 CONNECTOR BOOT 1
326 290326 DANGER LABEL 1
342 030342 BLACK TIE WRAP 4
404 010404 5/16-18 x 2-7/16 SS U-BOLT 2
403 010403 5/16-18 x 1.955 SS U-BOLT 2
70 190070 BOOM TO MAST PLATE 1
19 010119 5/16 SS SPLIT LOCK WASHER 8
18 010118 5/16-18 SS HEX NUT 8
X41 XHR41 41” X-HAT ROD 12
X26 XHR26 26” X-HAT ROD 8
28 190028 HALF WASHER 20
26 190026 ELEMENT BRACKET 20
85 010085 1/4-20 SS HEX NUT 6
84 010084 1/4” SS SPLIT LOCK WASHER 6
33 190033 U-BOLT BACKING PLATE 3
143 190143 ELEMENT TO BOOM CLAMP 3
402 010402 1/4-20 x 1-3/4” SS U-BOLT 3
11 010011 #8-32 SS HEX NUT 28
41 011941 #8 SS SPLIT LOCK WASHER 28
31 010231 #8-32 x 1 3/4” SS RH MACHINE SCREW 24
96 122096 FIBERGLASS INSULATOR 2
61 050061 7/8” BLACK PLASTIC CAP 6
410 030410 WORM CLAMP 7/16”-1” 12
411 030411 WORM CLAMP 9/16”—1-1/4”” 6
46 050046 1-1/2” BLACK PLASTIC CAP 2
413 030413 WORM CLAMP SS 3/4”—1 3/4” 4
Page 2
1 - BOOM ASSEMBLY
Place the worm clamps (413) over the slotted ends of tube BB. Slide
both BA sections into BB as shown in Figure 1. Each BA section
should be inserted 12 inches (30.5 cm) into section BB to leave 32
inches (81.3 cm) exposed on each end. Tighten the worm clamps.
Place the plastic caps (46) on the ends of the boom assembly.
MA5B
KEY P/N DISPLAY DESC SIZE QTY
18 010118 SS Hex Nut 5/16-18 4
19 010119 SS Lock Washer 5/16 4
Locate the boom to mast plate (70) at a distance of 36 inches (91.4
cm) from one end as shown in Figure 1. Bolt the plate to the boom
using the U-bolts (403), lock washers (19), and hex nuts (18). Apply
the danger label (326) to the boom near the mast plate.
FIGURE 1
2 PLACES
413
BA
88”
(223.5 cm)
46 050046 Plastic Cap 1-1/2” (3.8 cm) 2
70 190070 Boom To Mast 6” x 3-1/2” 1
403 010403 U-Bolt 5/16” x 2” 2
413 030413 Worm Clamp 1-3/4” 2
BA MA5BBA Aluminum Tube 1-1/2” x 44” 2
BB MA5BBB Aluminum Tube 1-5/8” x 24” 1
326 290326 Warning Label 1
BB
36”
(91.4 cm)
Plate (15.2 x 8.9 cm)
(5.1 cm)
(4.4 cm)
(3.8 x 111.7 cm)
(4.1 x 61 cm)
BA
46
2 PLACES
FIGURE 1A
18
BOOM
4 PLACES
19
4 PLACES
326
Page 3
SEE FIGURE 1A (BELOW)
FOR BOOM TO PLATE ASSEMBLY
70
403
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