Maintenance Requirements; Theory Of Operation - Palstar HF-AUTO RF NETWORK Technical Manual

MAINTENANCE REQUIREMENTS

I F T H E R E I S M A I N T E N A N C E R E Q U I R E D I T W I L L M O S T
L I K E LY B E R E L AT E D T O M E C H A N I C A L I S S U E S :
R O L L E R S H A F T : t h e w h e e l r i d e s s h o u l d b e l u b r i c a t e d
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w i t h o u r f a c t o r y - m a d e c o n d u c t i v e g r e a s e .
This grease is available from Palstar at NO CHARGE.
D I O X I T- D 5 s p r a y i s a l w a y s v e r y u s e f u l f o r c l e a n i n g t h e
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w i r e o n t h e r o l l e r c o i l . D o n o t u s e t h e s p r a y d i r e c t l y . P u t
a s m a l l a m o u n t o n a c o t t o n c l o t h a n d h a n d w i p e t h e
r o l l e r o n c e a y e a r w h i l e t u r n i n g t h e r o l l e r c r a n k .
A l l s e t s c r e w s a r e t h e C A P P O I N T t y p e a n d t a k e c a r e t o
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c a r e f u l l y t i g h t e n t h e s e s c r e w s w i t h a 5 / 1 6 " a l l e n k e y
w r e n c h , w h i c h i s a v a i l a b l e f r o m a n y h a r d w a r e o u t l e t .
R E PA I R O R R E P L A C E M E N T M O D U L E S
A l l P C B o a r d s a r e r e m o v e a b l e w i t h s t a n d a r d A m e r i c a n
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t o o l s i n c a s e o f f a i l u r e .
T h e r e a r p a n e l ( r e l a y
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c o n n e c t o r s t h a t c a n b e l o o s e n e d w i t h a 3 / 4 " s o c k e t a n d
4 x 6 - 3 2 k e p s n u t s . R e m o v e
c o n n e c t i o n s f r o m t h e v a r i a b l e a n d t h e e n t i r e r e l a y P C
B o a r d i s r e m o v a b l e w i t h o u t a s o l d e r i n g i r o n .
B o t h t h e f r o n t a n d r e a r p a n e l s c a n b e l o w e r e d b y
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r e m o v i n g t h e 3 c o u n t e r s i n k s c r e w s f r o m t h e b o t t o m e d g e
o f e a c h p a n e l .
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P C B ) h a s c u s t o m S 0 - 2 3 9
t h e s e n u t s a n d t w o

THEORY OF OPERATION

The HF-AUTO is a matching system that is a complete stand-alone RF
Tuneable Auto T Network tuner.
It is completely independent of data from an external source to
determine frequency of tracking from Band to Band. As a result of this
feature, the HF-AUTO will function with any transmitting device
without interconnecting data cable attachments.
The HF-AUTO uses an RF Coupler that provides voltage and current
information from 1.8 MHZ to 54 MHZ.
This informtion is then processed by a pair of processing devices that
provide accurate phase oriented forward and re ected values that are
used in two TI processors to calculate SWR.
This allows for detection of frequency and SWR at very low levels,
typically 2 watts, and is scaled to read these levels up to 1800 watts.
The processors establish the threshold for tuning and uses this
information to see if a tuning sequence is required.
A preset voltage for all the frequencies are used to determine the
positions of the variable di erential capacitor and the roller inductor
by a precise mechanical sprocket and kevlar belt system.
This determines with great accuracy and repeatability the exact
location of L&C needed to execute a tune sequence. This system
samples DC voltage and compares this to the intended frequency band
and sees that if the SWR is more than the preset tuning set by the user
then the steppers for L & C will adjust to that voltage which will
represent the mimimum SWR.
This will be better than 1.2:1, typically 1.05.
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