Hy-Gain TH3-MK3 User Manual

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INTRODUCTION

Hy-Gain's Model TH3-Mk3 Thunderbird is the ultimate in a 3 element
tri-bander for operation on
gain on all three bands and has maximum front-to-back ratio. The
TH3-Mk3 utilizes Hy-Gain's exclusive Beta Match system for a perfect

52

ohm input impedance on all bands giving you an SWR of less than

10, 15, 20

meters.

It

delivers at least 8 db

1.2:l.

This new Thunderbird is equipped with Hy-Gain's all new Hy-Q traps.
Threse traps have undergone exhaustive environmental testing at
Hallicrafters Reliability Evaluation Laboratory and passed all tests with
flying colors. The TH3-Mk3 also uses hardware that is iridite treated to
Military Specifications for maximum corrosion resistance. The large
diameter boom and all elements are constructed of heavy gauge
seamless aluminum tubing. Built for years of trouble-free service this is
absolutely the

finist 3 element tri-bander on the market today.

. TABLEOFCONTENTS

Section

1

GENERAL INFORMATION

General
Specifications

ASSEMBLY AND INSTALLATION

Preparation for Assembly
Assembly of the Boom
Assembly of the Reflector Element
Assembly of the Driven Element

Installation of the Beta Match

Assembly of the Director Element

Final Assembly

PARTS

LlST

Parts List

Page

Figure

LlST OF lLLUSTRATIONS

Hoisting Antenna (whole)
Hoisting Antenna (guy wire)

'Hoisting Antenna (halves)

Boom-to-Mast Bracket
Overall View of Th3-Mk3
Boom-to-Element Brackets
Compression Clamps
Beta Match
VSWR Chart

SECTION

GENERAL INFORMATION

1

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The Hy-Gain Model TH3-Mk3 is a 3 element tri-bander
designed for operation on 10, 15 and 20 meters.
Multi-banding is accomplished through the use of

all

Hy-Gain's

a

1 518" OD mast and can be rotated with a heavy

fit
duty TV rotator.

Electrical

Input Impedance
Gain

PREPARATION FOR ASSEMBLY:

Before leaping headlong into the assembly of this
antenna, take
TH3-Mk3 is a fairly large antenna and requires some
consideration as to how you are going to get
top of your tower. To help you with this problem we
have furnished you with three methods and
that you consider which you are going to use now, as
will determine how you put the antenna together.

Method 1 -Completely assemble the antenna on the
ground then hoist
tackle as shown in Figure No. 1.

Method 2 -The guy wire method (Figure No. 2) is a
simple inexpensive way of installing the antenna. Guy
the antenna as shown in the illustration and pull
position. This method requires that you make two boom
cradles as shown in the detailed drawing.

Method 3 -The last method is to assemble the antenna
on the ground in halves, then hoist each half up the

new Hy-Q traps. The antenna is designed to

SPECIFICATIONS:

:

.......................

...............................

ASSEMBLY AND INSTALLATION

a

moment to read this paragraph. The

it

into position using a block and

.52 ohms

.8 db min.

SECTION

it

to the

it

is best

it

it

into

Front-to-Back Ratio
Maximum Power. Input

(at

VSWR

Lightning Protection

Mechanical

Boom Length

Boom Diameter.
Longest Element
Maximum Wind Survival
Net Weight
Accepts Mast.
Wind Surface Area
Wind Load (80 mph)

2

tower and assemble in the boom-to-mast bracket on the
tower.

All tubing supplied with the TH3-Mk3 is designed to
telescope together. Make
possible using the dimensions given in this manual. If
this
antenna.

WHEN UNPACKING YOUR ANTENNA. CHECK THE
INSIDE OF ALL TUBING FOR PARTS (CLAMPS,

INSULATORS, SMALLER TUBING, ETC). TO
CONSERVE SPACE THESE SMALLER ARTICLES
ARE SOMETIMES PUT INSIDE LARGER PIECES.

Select the brackets, cast aluminum, the clamp,

boom-to-bracket, and the Bracket, casting-to-boom and
the two boom sections (2 x 84"). Slip the drilled end of
each boom section into the boom-to-mast bracket and

Resonance)

:

.............................

is

done you will gain optimum results from your

....................

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......................

..................

............................

..........................

..........................

..................

........................

....................

.......................

all

measurements as accurate as

CAUTION

.20-25 db

.1

KW AM

1.2:

1

.DC Ground

14 ft.

.2 in.
26

ft.

.80 mph

36 Ibs.

1 518" OD

.3.4

sq.

ft.

85 Ibs.

line up the holes. Secure the boom to the bracket using
the two 5/16-18 x 2 112" screws, nuts and lockwashers
provided. DO NOT tighten the screws at this time. The
bracket must be loose to enable you to mount the
antenna to the mast.

NOTE

The Boom-to-Mast bracket has a hole drilled in it for
connecting to the mast. Before the antenna has been
completely assembled and attached to the mast, drill a

3/8"

hole in the mast corresponding to the hole in the

bracket.

ASSEMBLY

LOOSELY assemble a set of element-to-boom brackets
on one end of the boom as shown in Figures

not forget the 1/4-20
with their associated square nuts as shown in Figure 6.

Position the bracket 2 1/2" from the tip of th boom to

the center of the bracket. This will be the Reflector end
of the boom.

The following steps will be in a singular form and they

will have to be done first for one side and then repeated
for the other side.

Select the R1 section of tubing (1 114 x 48", Item.4).

Slip the R1 section into the bracket assembled 0.n the

boom. Tighten the screws to hold the R1 section

securely but DO NOT TIGHTEN THE ANCHOR

SCREWS (Item 33) AT THlS TIME.

Check to see that the Reflector element will lie in a

plane horizontal to the earth when the antenna is

mounted on your mast. Do this by observing the

position of the element with respect to the
boom-to-mast bracket. Make any adjustments necessary
keeping the center of the bracket 2 112" from the tip of
the boom then tighten the anchor screws SECURELY.

OF

THE REFLECTOR ELEMENT:

5

x

112" taper point anchor screws

NOTE

and 6. Do

CAUTION

THE COMPRESSION CLAMPS FURNISHED ARE A
UNIVERSAL DEVICE AND MUST BE APPLIED AS
BELOW. DO NOT OVERTIGHTEN. CARE SHOULD
BE USED WHEN MEASURING THE TUBING

LENGTHS. THE COMPRESSION CLAMPS WlLL

INDENT BOTH TUBES MAKING READJUSTMENT
DIFFICULT. THE CLAMP IS PLACED NEAR THE
END OF THE TUBE,

WlTH THE SCREW

180

DEGREES FROM THE SLOT. IT SHOULD BE
TIGHTENED UNTIL THE INNER TUBE CANNOT BE
TURNED WITHIN THE OUTER TUBE. ONE HALF
TO THREE QUARTER FURTHER TURN OF THE
COMPRESSION SCREW BEYOND

THlS POINT WILL

PROVIDE A SECURE ELECTRICAL AND
MECHANICAL CONNECTION.
WHEN READJUSTMENT OR DISASSEMBLY
BECOMES NECESSARY THE TUBES CAN BE
SEPARATED BY REMOVAL OF THE CLAMP. IF THE

IT

SCREW HAS BEEN OVERTIGHTENED,

WlLL BE

NECESSARY TO FIRST DRILL OUT THE INDENT

114"

WlTH A SHARP

DRILL BIT. THE TUBES CAN
THEN BE SEPARATED AND THE COMPRESSION
CLAMP REINSTALLED.

Assemble a 1 114" compression clamp and slip
the R 1 section. Refer to Figure 7. Select the R2 section

(

1 118 x 48", ltem 7). Slip the unswaged (untapered)
end of the R2 section into the R1 section and measure
dimension
CW) as shown in Figure 5, then tighten the compression
clasp LIGHTLY.

Determine at this time which mode of transmission you
wish to favor, either phone or CW. The illustrations
show dimensions for both but you must use only one
mode throughout the assembly of this antenna. If you
should rttempt to use phone dimension on one band and
CW dimension on another band the antenna will not give
optimum results. The typical VSWR chart shown in
Figure
your particular application.

Assemble a 1" compression clamp and slip
swaged end of the R2 section. Select the 10 meter trap
(878749, ltem 16) and slip the SHORTED end into the
R2 section. Measure dimension C for your mode of
transmission as shown in Figure 5. Make certain the
drain holes in the traps are facing downward.

B

for your mode of transmission (phone or

NOTE

9

will help you decide which mode is best for

\

it

it

onto the

onto

CAUTION

THE TRAPS WlLL NOT OPERATE PROPERLY

UNLESS THE SHORTED END IS FACING TOWARDS

THE BOOM. THE SHORTED END CAN BE

IDENTIFIED BY THE PART NUMBER MARKING,

NEAR THE PLASTIC INSULATOR. THE END ON
WHICH THE PART NUMBER IS MARKED IS THE
SHORTED END. SEE FIGURE

Assemble two 1" compression clamps and slip them
onto the R3 section
section over the 10 meter trap then slip the SHORTED

end of the 15 meter parasitic trap (878694, ltem 15)

into the R3 section. Make certain the shorted end of the
trap (identified by the part number) is inserted into the

R3 section. Measure dimension D for your mode of

transmission as shown in Figure 5, keeping the R3
section approximately equidistant from the two traps.

Make certain the drain holes in the trap are facing
downward. Now tighten the compression clamps

(

1 x 5", ltem 13). Now slip the R3

5.

LIGHTLY.

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CAUTION

THERE

PART NO. 878694 IS A PARASITIC TRAP AND IS
USED ON THE REFLECTOR AND DIRECTOR. PART
NO. 878637 IS FOR USE ON THE DRIVEN
ELEMENT.

Assemble a 11/16" compression clamp and slip
the swaged end of the 15 meter trap. Select the R4
section (7116 x 28", Item 11) and slip
meter trap. Measure dimension E for your mode of
transmission as shown in Figure 5, then tighten the
compression clamp LIGHTLY.

Carefully recheck all measurements and make certain the
shorted end of all traps are pointed towards the boom.
Now tighten all compression clamps until snug. Do not

compress tubing too much or elements cannot be
telescoped if you want to change settings later.

ARE

MIO

STYLES

OF

15

METER

it

into the 15

TRAPS.

it

over

ASSEMBLY OF THE DRIVEN ELEMENT:

Select the larger set of element-to-boom brackets (Item

6) and LOOSELY assemble on the boom 72 314" from
the center of the Reflector element-to-boom bracket to
the center of the Driven Element-to-Boom bracket as
shown in Figure 5. Do not forget the taper point anchor
screws as shown in Figure 6.

Select the
and the element insulators (Item 55) from the parts
package. Slip the insulator over the DEl section then
slip the insulated end of DE1 into the bracket assembled
on the boom. Tighten the screws to hold the element
securely but DO NOT TIGHTEN THE ANCHOR
SCREWS (ITEM 33) AT THlS TIME. Refer to Figure 6.

Check to see that the Driven Element will lie in the same
plane as the Reflector and make certain
from the center of one bracket to the center of the
other. Now tighten the anchor screws SECURELY.

Assemble a 1 114" compression clamp and slip
the DE1 section. Select the DE2 section
ltem 9). Slip the unswaged end of the DE2 section into
the DE1 section and measure dimension G for your
mode of transmission as shown in Figure 5. Now tighten
the compression clamp LIGHTLY.

Assemble a 1" compression clamp and slip
swaged end of the DE2 section. Select the 10 meter trap

(878749, ltem 16) and slip the SHORTED end
(identified by the part number) into the DE2 section.

Measure dimension H for your mode of transmission as
shown in Figure 5. Make certain drain holes in trap are
facing downward. Now tighten the compression clamp

LIGHTLY.

Assemble two
the DE3 section (1 x 6", ltem 12). Now slip the DE3

DE1 section of tubing (1 114 x 48", ltem 4)

it

is

still 72 314"

it

over

(

1 118 x 38",

it

over the

1" compression clamps and slip then over

section over the 10 meter trap then slip the SHORTED
end of the 15 meter Driven Element trap (878637, ltem

14) into the DE3 section. Make certain the shorted end
of the trap (identified by the part number)
into the DE3 section. Measure dimension 1 for vour
mode of transmission as shown in Figure 5, keeping the
DE3 section approximately equidistant from the two
traps. Now tighten the compression clamps LIGHTLY.

Assemble a 11/16" compression clamp and slip
the swaged end of the 15 meter DE trap. Select the DE4
section (7116 x 28", ltem 11) and slip
end of the 15 meter DE trap. Measure dimension
your mode of transmission as shown in Figure 5 then
tighten the compression clamp LIGHTLY.

Carefully recheck all measurements as shown in Figure 5
and make certain that the shorted ends of the traps are
pointed towards the boom and the trap drain holes are
facing downward. Now tighten all compression clamps
SECURELY

it

is

slipped

it

over

into the swaged

J

for

IIUSTALLATION OF THE BETA MATCH:

Select the Beta Match tubes (314 x 46", ltem 10) and
the Beta support insulators and clamps as shown in
Figure 8. Assemble the Beta Match tubes on the boom as
shown in Figures 5 and 8.

Select the Beta Match shorting clamps and the shorting
strap and assemble as shown in Figure 8. Notice that the

10-24 x 1

the strap has a sleeve slipped over

install the shorting clamps without putting undue strain

on the Beta Match tubes.

Install the pigtail assemblies (Item 56) oh the Beta

Match tubes using the two No. 10 metal, screws (Item

32) and lockwashers (Item 42). Slip the'l 114" tubing
clamps on the Driven Element near the insulator.

LOOSELY attach the pigtails to the tubing clamps using

the 1/4-20 x 1 112" screws as shown in Figure 8. DO

NOT tighten the connection at this time. The coaxial

feedline will connect to, this point in a later step.

112" screw attaching the shorting clamps to

it.

This allows you to

ASSEMBLY OF THE DIRECTOR ELEMENT:

Select the remaining set of element brackets (Item 5)
and loosely assemble on the boom 91 314" from the
center of the Driven Element-to-Boom bracket to the
center of the Director Element-to-Boom bracket. Refer
to Figures 5 and 6. Do not forget the taper point anchor

screws as shown in Figure 6.

(

Select the Dl section of tubing

Insert the Dl section into the bracket assembled on the

boom. Tighten the screws to hold the element securely

but DO NOT TIGHTEN THE ANCHOR SCREWS

(ITEM 33) AT THlS TIME.

Carefully recheck the 91 314" measurement from the

1 114 x 48", Item 4).