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Field Service Procedure – Replacement Pol Pot Kit, USAT 

 

Page

 

7

 

of

 

7

 

 

Document No 

135929 Rev A

 

Copyright © Sea Tel, Inc 2012 - The information contained in this document is proprietary to Sea 
Tel, Inc.  This document may not be reproduced or distributed in any form without prior written 

consent of Sea Tel, Inc.  

 

 

10.

 

Verify

 

if

 

the

 

LNB

 

is

 

horizontal

 

in

 

the

 

center

 

of

 

the

 

pots

 

range

 

(120

 

counts),

 

if

 

the

 

LNB

 

is

 

not

 

horizontal

 

(as

 

per

 

Fig.

 

1.1)

 

repeat

 

steps

 

7

9

 

until

 

correct,

 

otherwise

 

move

 

onto

 

step

 

11.

 

*Note:

 

The

 

tolerance

 

for

 

calibration

 

of

 

the

 

pol

 

pot

 

is

 

+/

‐ 

2

 

degrees,

 

meaning

 

the

 

LNB

 

can

 

be

 

aligned

 

+/

‐ 

2

 

degrees

 

from

 

horizontal

 

at

 

a

 

pol

 

count

 

of

 

120.

 

Any

 

error

 

will

 

be

 

electronically

 

trimmed

 

using

 

the

 

pol

 

offset

 

function.

 

 

11.

 

Now

 

the

 

pot

 

is

 

correctly

 

aligned

 

verify

 

feed

 

has

 

the

 

complete

 

180

 

degree

 

range

 

of

 

motion

 

by

 

driving

 

the

 

assembly

 

from

 

end

 

stop

 

to

 

end

 

stop:

 

Enter

 

the

 

command

 

“g0020”

 

into

 

the

 

remote

 

command

 

screen

 

of

 

the

 

DAC.

 

This

 

will

 

drive

 

the

 

feed

 

assembly

 

to

 

its

 

lower

 

electronic

 

end

 

stop

 

(set

 

by

 

the

 

potentiometer).

 

Once

 

the

 

pol

 

motor

 

has

 

finished

 

driving

 

the

 

LNB

 

should

 

be

 

vertical,

 

to

 

the

 

left

 

of

 

the

 

OMT

 

with

 

the

 

coax

 

cable

 

pointing

 

downwards

 

as

 

shown

 

below

 

in

 

Fig.

 

1.4.

    

Now

 

enter

 

the

 

command

 

“g0210”

 

into

 

the

 

remote

 

command

 

screen

 

of

 

the

 

DAC.

 

This

 

will

 

drive

 

the

 

feed

 

assembly

 

to

 

its

 

upper

 

electronic

 

end

 

stop

 

(set

 

by

 

the

 

potentiometer).

 

Once

 

the

 

pol

 

motor

 

has

 

finished

 

driving

 

the

 

LNB

 

should

 

be

 

vertical,

 

to

 

the

 

right

 

of

 

the

 

OMT

 

with

 

the

 

coax

 

cable

 

pointing

 

upwards

 

as

 

shown

 

below

 

in

 

Fig.

 

1.5.

 

 

 

(Fig.

 

1.4)

                                                                                  

(Fig

 

1.5)

 

 

12.

 

Set

 

the

 

Pol

 

Type

 

to

 

automatic

 

(auto

 

pol):

  

Press

 

and

 

hold

 

the

 

 

arrow

 

keys

 

together

 

until

 

the

 

“EL

 

Trim”

 

or

 

“Auto

 

Trim”

 

window

 

is

 

displayed.

 

Push

 

the

 

 

arrow

 

key

 

to

 

scroll

 

through

 

the

 

settings

 

until

 

the

 

“Polang

 

Type”

 

window

 

is

 

displayed

 

and

 

press

 

the

 

 

arrow

 

key

 

to

 

activate

 

the

 

window.

 

Now

 

use

 

the

 

 

and

 

 

arrow

 

keys

 

to

 

scroll

 

the

 

cursor

 

along

 

and

 

use

 

the

 

 

and

 

 

arrow

 

keys

 

to

 

change

 

the

 

value

 

from

 

“0009”

 

to

 

“0072”

 

and

 

then

 

press

 

the

 

 

button

 

to

 

put

 

the

 

system

 

back

 

into

 

automatic

 

polang

 

(auto

 

pol)

 

mode.

 

Watch

 

the

 

LNB

 

and

 

verify

 

it

 

returns

 

to

 

the

 

correct

 

reception

 

position

 

(while

 

the

 

pol

 

motor

 

is

 

driving

 

the

 

target

 

light

 

will

 

be

 

illuminated

 

on

 

the

 

DAC).

 

*Note:

 

If

 

making

 

adjustments

 

to

 

the

 

polarization

 

alignment

 

of

 

a

 

VSAT

 

antenna

 

contacting

 

the

 

NOC

 

afterwards

 

to

 

run

 

through

 

a

 

cross

pol

 

isolation

 

test

 

and

 

calibrating

 

the

 

antennas

 

pol

 

offset

 

setting

 

will

 

be

 

necessary.

   

 

13.

 

Save

 

the

 

settings

 

in

 

the

 

DAC

2202:

 

Press

 

and

 

hold

 

the

 

 

arrow

 

keys

 

together

 

briefly,

 

“Save

 

New

 

Parameters”

 

will

 

be

 

displayed.

 

Press

 

the

 

 

arrow

 

key

 

to

 

activate

 

the

 

window

 

and

 

then

 

press

 

the

 

 

button,

 

“Parameters

 

Saved”

 

will

 

be

 

displayed

 

and

 

the

 

pol

 

type

 

and

 

pol

 

offset

 

will

 

be

 

stored

 

in

 

the

 

DAC.

   

 

Summary of Contents for USAT

Page 1: ......

Page 2: ...lookup table in the DAC If the system is unable to drive the pol motor to obtain the correct feedback or if the pot has failed and won t give the correct feedback the antenna can t complete the target process and the antenna will stay in this position Setting the pol type to 0009 will make the antenna target by removing the auto pol function from the targeting process however the miss alignment of...

Page 3: ...eaches its end stop Now measure the resistance between the slider and the counter clockwise contact grey cable pin 2 and the red cable pin 3 The feedback should be approximately 5k ohms Now slowly rotate the shaft of the pot counter clockwise the reading should count down sequentially After one and a half turns the pot will be in the center of its range giving a resistance of approximately 2 5k oh...

Page 4: ...eflector harness connector from the pol pot connection and then compress the retaining clips to remove the pol pot connector from its mounting bracket 2 Locate the pol pot on the feed assembly and remove it using a 9 64 Allen wrench The pot is secured via a single screw washer and star washer save the hardware for future use 3 Now using the parts supplied in the kit build up the replacement pol po...

Page 5: ...ible if there is a large amount of error in the pot alignment 6 Install the replacement pot assembly onto the feed by looping the pulley through the belt Then install the flat washer followed by the star washer onto the retaining screw and apply Loctite 242 to the thread Pull down on the assembly to tension the belt and tighten the retaining screw Note Additional mounting hardware is provided in t...

Page 6: ...ton again to display the Pol Offset window Verify the pol offset is set to 0030 if not press the arrow key to activate the window Now use the and arrow keys to scroll the cursor along and use the and arrow keys to change the characters to 0030 and press the button 4 Now press the button again to display the Pol Scale window Verify the pol scale is set to 0090 if not press the arrow key to activate...

Page 7: ...alue Enter g0130 g0135 g0137 and so on into the remote command screen until the LNB is aligned horizontally Should the LNB be over to the right of center and needs to be driven counter clockwise to bring it to horizontal decrease the pol value Enter g0110 g0105 g0103 and so on into the remote command screen until the LNB is aligned horizontally 8 Once the LNB has been aligned horizontally as per F...

Page 8: ...screen of the DAC This will drive the feed assembly to its upper electronic end stop set by the potentiometer Once the pol motor has finished driving the LNB should be vertical to the right of the OMT with the coax cable pointing upwards as shown below in Fig 1 5 Fig 1 4 Fig 1 5 12 Set the Pol Type to automatic auto pol Press and hold the arrow keys together until the EL Trim or Auto Trim window i...

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