VHF YAGIASSEMBLY INSTRUCTIONS

l. For pre-cut models with no "k" suffix, your elements arecoded as follows:

Ref lector . . . . . .b lackdot Di rector2. . . . . .greendotDriven .......... red dot Director 3 ......yellow dotDirector 1 .... blue dot Director 4......brown dot

2. For "k" suffix, field tunable models, proceed as follows:Locate the frequency ofoperation for your antenna modelon the element cutting chart for the model Yagi youpurchased. Record the lengths required for the variouselements.

3. Pick out the 3/8" diameter elements and mark them as toreflector, DI,D2, etc.

4. Cut each element to the length described in the cuttingchart measuring from the center mounting hole and trim-**=* .ming ateach end..- *-.-.--. ._-. +:-. Í\-

RememberThe element has a center mounting hole.

This hole should be at the midpoint of the cut element.

5. Slide the connector block assembly onto the boom andposition it between the driven and reflector element holesin the boom.

6. Slide each trimmed element into the proper 3/8" hole in theboom. Align the cross hole in the boom with the threadedmounting hole in the element. Fasten each elernent usinga 10-32 hex bolt, #I0 lockwasher and #l0 nut.

'/. Put the end caps onto the boom and elements.

8. For the iix element models, the I - 1/8" boom section holdsdirectors D3 and D4. This section inserts into the 1-l/4',boom and is anchored with element D2 passing throughboth booms.

NOTE: Insert the end with a 3/8" elementhole l/2" fiom theend into the 1-l14" boom.

9. Assemble the gamma match feed to the driven element andboom. Before securing, set the capacitor tube dimension

- A to l " andc lampd imens ionB to3 -1 ¡2 " . Th i s i sas ta r t i ngpoint for tuningihe gamma match to yield zero .é1166Téipower. Put the end cap onto the gamma match capacitortube.

10. BEFORE INSTALLATION, set the antenna up in a cleararea and inseft a VSWR indicator thru-line wattmeter intothe line. If the reflected power is too high, the gammamatch must be adjusted. First, adjust the gamma tube fora minimum reflected power reading. Next, adjust theshorting clamp for minimum reflected power. In order toreduce the VSWR to I .0, several runs of adjusting the tubefirst, shorting clamp second, may have to be made.

I I . It is recommended that in vertically polarized installations,the gamma match capacitor tube cap is "up".

NOTE: Except for the MYA-1503FT, the dimensions givenare for the total element leneth. The hole in the element shouldbe the center.

DR

ELEMENT-TO-BOOM ASSEMBLY

Boom

REF

GAMMA-MATCH

YOU COULD BE KILLED IF THIS ANTENNACOMES IN CONTACT WITH ELECTRICPOWER LINES OR IS BROUGHT IN PROX-IMITY WITH A HIGH VOLTAGE ELECTRI-cAL FIELD. FOR YOUR OWN SAFETY, USEEXTREME CAUTION WHEN II\STALLINGTHIS ANTE¡{NA. KEBP AWAY FROM POWERLINES.

EXTREMELY IMPO

MYAI406

Example:The dark line indicates that the approximate length

for the reflector tuned to 140 MEz is ALllrches. '-

l l lFREQUENCL (NaH, f )

MYA15O3FT

l 9

1 a

t 7

t 6

7 4150 152 t 54 1 56 I 5a I 60 1 62 1 64766 l 6a 17 ( ) 172 174

FR.EQIJE\TC-II (\,'TFIZ)

Example:The dark line indicates that the approximate length

for the reflector tuned to 166MHz is 17.125 inches.

R e l

DRD 1

MYA14O5

DR

D1 ANO 03

D2

45

F 4 4( a

Z + t

¡ , ,4l

40

J9

J8

37

J6

l5

J4il4 136 138 R0 142 144 146 118

FREQUENCY (MHz)

ExamPle:The dark line indicates that the approximate length

the reflector tuned to 146 MHz is 39.5 inches.

MYA1403

F(?z¡

t5

+3

42

4 1

40

3 9

3 a

3 6

3 530 132 134 136 13a 140 742 144 146 148

FREQIJENTC)r (N4Hz)

Example:The dark line indicates that the approximate length

for tlre reflector tuned to I44}{Hz is 40 inches.

T: SELECTitional charts

THE CORRECT CUTTINGand assembly instructions on

MYA15O3K

CHART FOR YOUR YAGI!back)

MYAl5O5

39

38

37

36

35

34

33

32

3 1

30

2 9

2 8

150 152 154 1 56 1 58 '1 60 162 164 166 164 170 172

F R E Q U E N C Y ( M H z )

Example:The dark line indicates that the approximate length

for the D1 tuned to 166 MHz is 31.75 inches.

F l¿3F

zt¡l¡ t 6

3 5

3 4

3 3

3()

2 9| 5 0 | 52 | 5 4 | 56 | 5 ta | 60 1 62 1 64 | 66 t óa 1 ' / O | 72 | a 4

FREQUE'NC-r (N4Hz)

Example'

The dark l ine indicates that the approximate length

for the rc f lec to r tuned to 158 MHz is 36 .25 inches .

MYA2203K

(/)F

UZ

F(,zq

I

2a

27

26

21

20230 235 240

FREQUENCY (MHz)

Example:Tl.re dark line indicates that the approximate length

lbr the DR tuned to 250l/Hz. is 20.70 inches.

MYA22O3FT

EF

ZJ

t 4

13.5

l 2

il

l0.s

t 0

9.5

D ]

D R

t20 230

FREQUENCY (MHz)

E ramp le :The dark line indicates that the approximate lengthfbr tf.re reflector tuned to 234 MIlz is I 1.90 inohes.

MYAl506

rF

z¡

l a

3 6

3 5

34

3 3

3 0

29

2 a1 50 1 52 Is4 Is6 I 5A I60 1 62 7 64 1 66 t6a t70 172 1 74

FREQTJENC\- (I\aHz)

Example:

The dark line indicates that the approximate length

for the reflector tuned 10 170 l'4Hz is 33.5 inches.

DRD 1 ,D4D2.D3

MYA22O5

F(,zJ

zl

6

E

A

a

2

21

n

l9

DR

Dl ardB

wm a 5 2 f i

FREQUENCY (MHz)

Examnle:The dark line indicates that the approximate length

for the D2 tuned to 235 MHz is 21 .625 inches.

ltr:=

---=-

\\-!+

''\'-

\

:\ .\

\

A

-Fa l

zJ

2.4

22

2 I

20

t 9

l a

t 7

---\\-

.-\\.-

---\

Ref

DR

DI ,D3D2

25() 255 260 26s 270 2'7s 2aO 245

FREQLIENC)r (\aHz)

Example:The dark iine indicates that the approximate lengthfor the reflector tuned to 275 MHz is 20.875 inches.

MYA25O5 MYA3503

MYA35O5

MYA35O6

3so 3s5 360 36s 370 37s 3aO 3as 390 395 400

FR-EQLIENCY (l\[Hz)

Example:The dark line indicates that the approximate lengthfor the reflector tuned to 375 MHz is 15.625 inches.

1 7

t 6

1 5

I 4

1 3

1 2

t l35c) 355 36() 365 370 375 3aO 3a5 390 395 400

FR-EQIJENCY (N4Hz)

Example:The dark line indicates that the approximate lengthfor the reflector tuned to 380 MHz is 15.25 inches.

360 3'70 3aO 390 40u

FREQLIENC-Y (\aHz)

Example:The dark line indicates that the approximate lengthfor the reflector tuned to 390 MHz is 15.375 inches.

MYA3O03

Fr l

z¡

8,5

18,0

17,5

17.0

165

160

155

150

14,5

14.0

Ref

DR

315 320 325 JJo JJ5 J40

FREQUENCY(MHz)

Example:The dark line indicates that the approximate lengthfor the reflector tuned to 305 MHz is 17.5 inches.

Fr lzr¡.1¡

2 l

) n

l 9

1 a

1 6

t 5

t 4

1 3

Ref

DR

D ID2,D3

300 3( )5 31 t ) 315 320 325 330 335 340 345 350

FREQIJEIrICY (N4Hz)

Example:The dark line indicates that the approximate lengthfor the reflector ttrned to 310 MHz is 19.5 inches.

LOWBAND YAGIS

l .

LOWBAND YAGIASSEMBLY INSTRUCTIONS

Locate your frequency ofoperation onthe cutting chart andrecord the lengths required for the various elements.

Pick out the 5/8" elements and mark them as to reflector.driven element" Dl"D2 and D3.

Cut each element to the chart length, measuring from thecenter mounting hole and trimming at each end.

Slide each element into the proper 5/8" hole in the boom.

NOTD: For the MYA725, first insert the smaller diameterboom into the larger diameter piece (long end into the boom)and pass Dl through both pieces. Align the cross hole in theboom with the mounting hole in the element. Fasten eachelement wingiit+-20 hex bolt, lockwasher and nut.

Remember

6.

7 .

The bolt must be inserted through the element.

Put the end caps onto the boom and elements.

Assemble the gammamatch feedto the driven element andboom. Before securing, set the capacitor tube A to L2', andclamp dimension B to 9". This is a starting point for tuningthe gamma match to zero reflected power, Put the end capon the gamma match capacitor tube.

BEFORE INSTALLATION, set the antenna up in a cleararea and insert a VSWR indicator (thru line wattmeter) intothe line. If the reflected power is too high, the gammamatch must be adjusted. First, adjust the gamma tube fora minimum reflected power reading. Next, adjust theshorting clamp for a minimum reflected power reading. Inorder to reduce the VSWR to 1.0, several runs of adjustingthe gamma tube first, shorting clamp second, may have tobe made.

It is recommended that in vertieally polarized instalthe gamma match capacitor tube cap is "up".

YOU COULD BN KILLED IF THIS ANTENNACOMES IN CONTACT WITH ELECTRICPOWER LINES OR IS BROUGHT IN PROX.IMITY WITH A HIGH VOLTAGE ELECTRI-CAL FIELD. FOR YOUR OWN SAFETY. USEEXTREME CAUTION WHEN INSTALLINGTHIS ANTENNA. KEEP AWAY FROM POWERLINES.

2.

3 .

a .

5 .

N{YA723

4 3 4L: * q ?

Z < o¿ / ó

7 6

74

72

70

6 8

66

6a 70 72 74 76 7A aO a2 84 a6

FREQIJENCY (I\{FIz)

Example:The dark line indicates that the approximate length

for the reflector tuned to 72MHz is 78 inches.

62605 a56

MYA725

+ 3 4t- 32

2,ofi 78- 1 6

7472706 a666462605 a5 654

6a 70 72 74 76 7a aO a2 84 a6

FREQIJE]rIC)T (\4HZ)

Example:The dark line indicates that the approximate lengthfor the reflector tuned to 82MHz is 70.0625 inches.