TS-4408
1 4
CIRCUIT D ESCRI PTION
FULL BREAK-IN
A
:
H
B
L
c
H
L
D
L
H
E
L
F
L
G
L
H
:
S E M I BREAK-IN , VOX
A
F
J
H
L
H L
H
L
H L
L_
KEYING IN
KEYING OUT
CONTROL OUT
KEYING
IN
CONTROL OUT
KEYING
OUT
vox
Fig . 9-3 FULL/S E M I BREAK-IN timing chart
The above timing charts show the timing for sta ndby and
keying sig n a l s .
When an i n p u t from the CW key i s supplied t o point A a s
shown in the above fig ure d u ring full break-in operation,
the one-shot multi-vibrator and gate circuits generate con
trol (fu ll) and delayed keying (fu l l) sig n a l s . After the fun
d amental timing sig nal, RL ( 1 2V) for reception and
transmission rises, the keying wave also rises, and when
the key is off, RL falls according to the preset time
constant.
S emi-break-in operation is synchronized to V OX . When a
sig nal is supplied to point A, the V OX delay time mu lti
vibrator determines the VOX time constant. The input sig
n al is converted to a keying (semi) signal by the gate
circuit.
These keying semi/full a n d control semi/full signals a re
converted to a ppropriate break-in VOX mode signals us-
ing the slide switch . The control sig n a l is checked by the
microcomputer to see whether transmission is to be per
formed . The control signal is then used to switch CRL in
the
IF
assembly u nit and generate RL ( 1 2 V). TXB (trans
mit B + )
(8. 8
V) is generated, synchronized to RL . The
receive control sig nal RXB (receive B + )
(8.8
V) turns
on/off, synchronized to the inverted TXB signal, that is, RL .
RL
TXB
RXB
8.81/
Fig . 1 0 STAN DBY keying timing chart
