Hy-Gain LJ-115 User manual

CAUTION: Read All Instructions Before Operating Equipment
308 Industrial Park Road
Starkville, MS 39759 USA
Tel: [phone] Fax: [phone]
COPYRIGHT 2012 Hy-gain.
VERSION 1A C
LJ-115
5 element beam for 10 or 12 meters
INSTRUCTION MANUAL

GENERAL DESCRIPTION
This model is a 5-element beam tunable for maximum forward gain over the entire 10 or 12
meter band. Both the antenna and the beta match are adjustable for maximum performance. The
elements are made of aircraft grade aluminum. The bracket will fit up to a 2 inch diameter mast.
The electrical hardware is made from super strength stainless steel and all element tubing clamps
are stainless steel.
This antenna is designed for use with a 50 ohm coaxial cable. A RG-213/u coaxial cable is
recommended for lower losses and higher power handling capabilities. The antenna requires a
coaxial choke (or balun) to prevent the unbalanced current from flowing down the transmission
line and affecting the efficiency and match of the antenna.
VSWR AND FEEDLINE
UNPACKING
Unpack the antenna and check the parts against the Parts List and the drawings. This will simplify
the antenna assembly.
WARNING
WHEN INSTALLING YOUR SYSTEM, TAKE EXTREME
CARE TO AVOID ANY ACCIDENTAL CONTACT WITH
POWERLINES OR OVERHEAD OBSTRUCTIONS.
FAILURE TO EXERCISE THIS CARE COULD RESULT
IN SERIOUS OR FATAL INJURY
2
Boom center inside mast bracket
No bolts needed
fasten with 10-24 x 1-1/2 bolts
split washers and nuts
fasten with 10-24 x 1-1/2 bolts
split washers and nuts
BOOM ASSEMBLY
Assemble the boom with the holes facing the direction shown. Use Bolts to fasten the outer sections
together and then slide the two into the mast bracket as shown in the next step. Don’t forget the
insert in the middle section.

BOOM-TO-MAST ASSEMBLY
Select the boom to mast bracket and clamp and install it on the boom as shown in figure 1.
Use only the four outside holes, the elongated inside holes will be used for the U-bolts.
The boom sections should meet in the middle of the bracket.
Figure 1 Figure 2
ELEMENT-TO-BOOM BRACKET
Select a set of small sized element to boom
brackets and loosely assemble them on one
end of the boom. Refer to Figure 2 for a
assembly detail of the bracket. Do not forget
the 1/4 x 3/8 anchor bolt and its associated
square nut. This will be the reflector end of
the boom.
INSTALLATION OF CLAMPS
When installing the clamps, place the
clamp near then tube with the top of
the clamp centered over one of the
slots in the tube as shown in Figure 3. Figure 3
26 27
31
29
30
26
9
3
27 4 places
32
29-30
33-34
12
13
2
1
NOTE: Bolts not required to join middle sections.
2
When placing brackets on boom, refer to the diagram on page 6. Because the element placement
will change with operating frequency, mark the location of the elements on the boom to ensure they
do not fall on top of a boom joint or the mast bracket. An easy way to do this is to lay the brackets
on the ground using the measurements of the frequency you will operate. Assemble the boom and
lie it next to the brackets. Move the boom back and forth until you find a location that does not
interfere with the joints.

R1 ASSEMBLY
Select the R1 section of tubing and slip the un-slotted end into the bracket assembled on the
boom. Tighten the bolts enough to hold the elements securely but do not tighten the anchor
bolts at this time. Adjust the bracket until it is a few inches from the end of the boom and will
lie in a plane horizontal to the earth when the antenna is mounted on the mast. Snug the bolts
untill the element will remain in place. Exact placement will be determined by the frequency
you chose to operate. Refer to the frequency chart for placement and tighten the bolts when
the correct location is found.
R2 ASSEMBLY
Select the R2 sections and slip the un-slotted ends into the R1 sections. Allow at least 2 inch
of over lap between the tubes and install the #6 hose clamp and tighten.
R3 ASSEMBLY
Select the R3 sections and slip them into the R2 sections. The total element length may be
adjusted by sliding the R3 in or out of the R2 sections. Refer to the chart to adjust the total
element to the correct length. Install the hose clamps and tighten.
Figure 4
Assemble both sides at
the same time.
l t i o r
Total eement lengh = t p t cente of boom
Figure 5
5
3
4
16
16
5
5
R1
R2
R3
4
All measurements are in inches and may vary with mounting location and height above
ground. Note that some tubing will be longer than needed for the measurements given.
Overlaping the inner sections as much as possible will lessen the weight present at the
tips of the element and lower the moment of the antenna.

DRIVEN ELEMENT ASSEMBLY
Select the large size set of element-to-boom brackets and loosely assemble these
brackets on the boom in the approximate location according to the assembly chart.
Select the driven element insulators and the DE1 sections of tubing. Slide the
insulator on to the un-slotted end of the R1 (5) sections. Slip the insulated ends into
the bracket assembled on the boom. Tighten the bolts to hold the element securely
but do not tighten the anchor bolts at this time. Carefully check the measurement
from the center of the reflector bracket to the center of the driven element bracket.
Make certain the driven element will lie in the same plane as the reflector then tighten
the anchor bolts securely.
Select the R2 section and slip them into the R1 section. Overlap the tubing at least
2 inches and install the hose clamp and tighten. Select the R3 section of tubing and
slip it into the R2 section. Refer to the chart for the total length of the driven element.
Install the hose clamp and tighten.
DIRECTOR ELEMENT ASSEMBLY
Install the directors using the same assembly method as the reflector. Refer to the chart
for total length of the element and location.
Figure 6
31
29
30
26
8
19
5
16
27
26
5

A
B
C
E
D
7/8 x 48
3/4 x 48
5/8 x 40-1/2
T1 T2 T3
T1
T1
T2
T2
T3
T3
Ref
DE
Dir
Figure 7
T1 T2 T3
Dir
T1 T2 T3
Dir
F
G
H
I
6
A
B
C
D
E
10 MTR 12 MTR
Ref
DE
Dir
F
Beta 11 15
Dir
Dir
G
H
I
J
10 MTR 12 MTR
97-15/16
108
93-3/4
91-7/16
89
123-5/8
112-1/8
107-3/8
104-5/8
101-15/16
58-1/8
48-3/4
41-7/16
42-1/4
66-1/2
55-7/8
47-7/16
48-3/8

BETA MATCH
Select the beta rods, the beta clamps and the 7/8 tubing clamps. Assemble the
beta match as shown in Figure 8. Adjust the beta match “J” dimension measured
from the inside edge of the driven element to the inside edge of the beta clamp as
shown. Tighten all screws securely.
FINAL ASSEMBLY
A balun is not required for normal operation of this antenna. However there are three
recommended feedpoint configurations. one which utilizes the Hy-gain Model BN-86
balun for increased performance and convenience. Final tuning may be required as
the element lengths will vary based on mounting location and height above ground.
Use a good SWR analyzer such as the MFJ-259 or a quality wattmeter to verify the
tuning of the antenna before mounting it in its final location. If the resonance point of
the antenna is too high, then the elements are too short. If it is too low then the
elements are too long. If the resonance point is in the correct place but the SWR is
higher than it should be, then dimension F on the Beta match in Figure 8 should be
adjusted to lower the SWR.
J
21-22-24
21-24-22-24
Refer to chart
Figure 8
7

The first feedpoint configuration involves connection of the coaxial feedline directly to the
driven element. The recommended feedline is RG-213/U. Other types of 50 ohm coaxial
cable may be used if proper selection and careful assembly are utilized. The feedline
should be stripped as shown in figure 10. Attach solder lugs (not supplied) to the center
conductor and shield for easy connection to the driven element.
The second feedpoint configuration involves construction and installation of a homemade
RF choke. (Figure 9)The RF choke ill prevent Rf from flowing on the outside of the coaxial
shield. This will block radiation from the coaxial feedline, thereby reducing the risk of TVI and
preventing radiation pattern degradation. Wind the RF choke from RG-213/U (or equivalent)
coaxial cable. The choke should consist of 12 turns with an inside coil diameter of 6 inches.
Allow enough cable at the end to reach from the mast to the driven element. Strip the coaxial
cable as shown in figure 10. Attach solder lugs ( not included) to the center conductor and
shield for easy connection to the driven element.
The third feedpoint configuration involves using a 50 ohm 1:1 balun to connect the feedline
to the driven element. A balun will act as an RF choke and will balance the flow of current
on the driven element, resulting in a symmetrical radiation pattern. A balun will also have a
coaxial connector, providing more convenience than a coax splice. Follow the instructions
supplied with the balun for connection to the antenna.
RF Choke: 12 turns of
RG-8/U with a six inch
diameter. For optimum
performance, use a
Hy-gain BN-86 balun in
Place of the choke.
Tape
Tape
Boom to mast
bracket
Figure 9
Figure 10
8

INSTALLATION AND GROUNDING
The antenna is now ready to be mounted on your mast. This antenna may be mounted
vertical or horizontal. If you choose to mount the antenna vertical, it is strongly suggested that
you drill the lower elements at their junction and install screws in addition to the hose clamps.
This will prevent the elements from falling if they become loose. You must also install the
element brace on the lower element closest to the boom. This will prevent the element from
swaying which may cause the SWR to change.
A proper ground consist of a ½”x 8’ copper-clad ground rod driven into the ground 12
inches from the base of the supporting structure.
Connect the ground rod to the supporting structure using a #8 or larger copper wire
and commercial non-corrosive ground clamps.
WEATHERPROOFING
Weatherprooof the coax connectors using Coax-Seal or similar substance (not supplied).
Securely tape the RF chokke and feedline to the antenna boom. Later when the antenna
is mounted on the mast, the RF choke should be taped to the mast.
Place a Caplug on the end of each boom.
Place a Caplug on the end of each element.
Plastic insulator Metal spacer
7/16 clamp
1-3/4 clamp
mast clamp
mast
Driven
element
21-22-24
Figure 11
21-22-24
21-22-24
37
36
35
38
9

PARTS LIST
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
190355
190362
190004
174865
190206
165138
165141
172267
385142-1
385144-1
871994
163312
166084
745-3106S
500159
455630
463767
475639
504069
565697
656S-0375S-A
554071
500156
505266
562961
554099
551367
540067
564792
555747
161855
161851
465416
169339-0
Boom Splice 1-1/8 x 8 Drilled ------------------------------------
Boom, 1-1/4 .058 x 56 Drilled -----------------------------------
R2, 5/8” x 24”, swaged----------------------------------------------
R3, 7/16” x 48” -------------------------------------------------------
R1, 7/8” x 55” --------------------------------------------------------
Bracket #1 element to boom 1-1/4 x 1-1/4---------------------
Bracket #2 element to boom 1-1/4 x 7/8------------------------
Beta match rod 20”--------------------------------------------------
Boom to mast bracket-----------------------------------------------
Clamp, boom to mast bracket-------------------------------------
PARTS PACK LJ-115 -----------------------------------------------
Clamp, 7/8 tubing----------------------------------------------------
Clamp, beta-----------------------------------------------------------
#6 Hose clamp-------------------------------------------------------
Bolt, 10-24 x 1-1/2 -------------------------------------------------
Caplug, 1-1/4---------------------------------------------------------
Insulator, driven element------------------------------------------
Caplug, 7/16 --------------------------------------------------------
Bolt, #10-24 x 1”, hex head--------------------------------------
Lockwasher, #10 internal-----------------------------------------
Screw #6 self tap stainless ------------------------------------
Nut, #10-24, hex-----------------------------------------------------
Bolt, 1/4-20 x 3/8”, hex head-------------------------------------
Bolt, 1/4-20 x 3/4”, hex head-------------------------------------
Lock washer, 1/4”, internal----------------------------------------
Nut, 1/4”, hex --------------------------------------------------------
Nut, 1/4”, square----------------------------------------------------
U-bolt, 5/16” x 2” x 3-5/8”-----------------------------------------
Lockwasher 5/16”, split--------------------------------------------
Nut, 5/16”-18, hex---------------------------------------------------
Clamp, 1-3/8 --------------------------------------------------------
Clamp, 7/16 ---------------------------------------------------------
Insulator, element brace -----------------------------------------
Spacer, element brace ------------------------------------------
3
4
10
10
10
2
8
2
1
1
1
2
2
20
4
2
2
10
12
13
20
18
10
40
40
40
10
2
4
4
1
1
1
1
10

hy-gain®LIMITED WARRANTY
hy-gain Warrants to the original owner of this product, if manufactured by hy-gain and
purchased from an authorized dealer or directly from hy-gain to be free from defects in
material and workmanship for a period of 12 months for rotator products and 24 months
for antenna products from date of purchase provided the following terms of this warranty
are satisfied.
1. The purchaser must retain the dated proof-of-purchase (bill of sale, canceled check,
credit card or money order receipt, etc.) describing the product to establish the
validity of the warranty claim and submit the original or machine reproduction of
such proof-of-purchase to hy-gain at the time of warranty service. hy-gain shall have
the discretion to deny warranty without dated proof-of-purchase. Any evidence of
alteration, erasure, or forgery shall be cause to void any and all warranty terms
immediately.
2. hy-gain agrees to repair or replace at hy-gain’s option without charge to the original
owner any defective product under warranty, provided the product is returned postage
prepaid to hy-gain.
3. Under no circumstances is hy-gain liable for consequential damages to person or
property by the use of any hy-gain products.
4. Out-of-warranty Service: hy-gain will repair any out-of-warranty product provided
the unit is shipped prepaid. All repaired units will be shipped COD to the owner.
Repair charges will be added to the COD fee unless other arrangements are made.
5. This warranty is given in lieu of any other warranty expressed or implied.
6. hy-gain reserves the right to make changes or improvements in design or manufacture
without incurring any obligation to install such changes upon any of the products
previously manufactured.
7. All hy-gain products to be serviced in-warranty or out-of-warranty should be
addressed to hy-gain, 308 Industrial Park Road, Starkville,
Mississippi 39759, USA and must be accompanied by a letter describing the
problem in detail along with a copy of your dated proof-of-purchase.
8. This warranty gives you specific rights, and you may also have other rights which
vary from state to state.