Kenwood TS-440S Service Manual page 14

TS-4408
FULL B R EAK-IN
: _J
A
H
L
B
H
L
c
L
D
H
L
E
L
F
L
G
: _J
H
S E M I B R EAK-IN , VOX
H
L
A
H
L
H
L
F
H
L
J
The above timin g cha rts show the timi n g for sta n dby a n d
keying sig n a l s .
When a n i n p u t from the C W key i s s u p p lied t o point A a s
show n in the above fig ure d u ring f u l l break-in ope ration,
the one -shot mu lti-vibrator and g ate circ uits generate con­
trol (fu l l) and d e l ayed keying (fu l l) sig n a l s . After the f u n­
d amental timin g sig n a l , RL ( 1 2V) for receptio n a n d
tran smission rises, the keying w a ve a l s o ris e s, a n d when
the key is off, RL f a l l s acco rding to the p reset time
constant.
S emi-bre ak-in ope ration is synchro nized to V OX . When a
sig n a l is s u p p lied to point A, the V OX d e l ay time mu lti­
vibrator determines the VOX time constant. The input sig­
n al is converted to a keying (semi) sig n a l by the g ate
circuit.
These keying semi/f u l l a n d control semi/f u l l sig n a l s a re
converted to a p p r o p riate bre ak-in VOX mod e sig n a l s u s -
1 4
CIRCUIT D ESCR I PTION
Fig . 9 - 3 FULL/S E M I BR EAK-IN t i m i n g chart
RL
TXB
RXB
L_
ing the s l ide switch . T h e c o n t r o l sig n a l is checked b y the
microcomputer to see whether tran smission is to be per­
formed . The control sig n a l is the n used to s witch CRL in
the IF assembly u nit a n d g e n e rate RL ( 1 2 V ) . TXB (trans­
mit B + ) (8. 8 V) is g e n e rated, synchro nized to RL . The
receive control sig n a l RXB (receive B + ) (8.8 V) turns
on/off, synchronized to the inverted TXB sig n a l, that is, RL .
8.81/
Fig . 1 0 S TAN DBY key ing timing c h a rt
KEYING IN
KEYING OUT
CONTROL OUT
KEYING
IN
CONTROL OUT
KEYING
OUT
vox