Kenwood TS-830S Service Manual page 9
Ssb transceiver
Hide thumbs
Also See for TS-830S:
- Instruction manual (39 pages) ,
- Operating manual (6 pages) ,
- Instruction manual (38 pages)
Table of Contents
( 8 8 2 9 5
kHz ( N o 1 IF) - 8 3 7 4 . 0 kHz (CAR-2)
=
4 5 5 5 kHz)
Thus rhe second IF slgnal
IS
shifted by + 5 0 0 Hz, and as a
result the upper-s~de frequency components are cut by
500
Hz, as
illustrated
In ( 4 ) The frequency spectrum of the s ~ g n a l
whlch has passed the second IF stage
IS
4 5 5 5 k H z k 8 5 0 Hz
and the bandwidth
I S
1
7 kHz
If w e convert the srgnal fre-
quency t o an equlvalen~ one a1 the ANT Input, w e obtaln
1 4 . 0 0 1 5 M H z + 8 5 0 Hz I n t h ~ s case IF SHIFT
operation
is
not performed
Example 2
Bandw~d.rh 1 7 kHz
IF SHIFT
5 0 0 Hz (poslt~ve s h ~ f t )
I
When the frequency of CAR-2 is lowered by 1 kHz with the
VBT control and that of CAR- 1 ralsed by 5 0 0 Hz w l t h the
SHIFT control, the resulting frequenc~es of CAR-2 and -1 are
CAR-1
8 8 3 1 5 k H z ( = 8 8 3 1 5 k H z - - 0 . 5 k H z * l + 0 5
kHz"2)
CAR-2
8 3 7 4 0 kHz
*I
Half the amount of frequency varied by VBT
* 2 The amount of frequency rise with IF SHIFT
Let us examine the frequency spectrum of the ANT input
slgnal from the second IF component in Example 1
You will recall that the center frequency of the second IF
signal component is 4 5 5 . 5 kHz and the upper limit 4 5 5 . 5
k H z + 8 5 0 Hz
The signal is 4 5 5 . 5 kHz f 8 3 7 4 . 0 kHz= 8 8 2 9 . 5 kHz in the
flrst IF and the lower llmlt 8 8 2 9 . 5 k H z - 8 5 0 Hz. As a result.
signal components which have passed an 8 8 3 0 kHz fllter
and a 4 5 5 kHz fllter are the same as In Example 1 But the
VCO output is 2 2 . 8 3 1 5 M H z because CAR-1 which was
8 8 3 1 0 kHz
1 1 1
Exarrlple 1 is 8 8 3 1 5 kHz in Example 2 Slnce
the converted equrvalent frequency range at the flrst IF is
8 8 2 9 . 5 k H z k 8 5 0 Hz, ~ t s equivalent at the ANT Input
I S
1 4 . 0 0 2 M H z k 8 5 0 Hz.
( 2 2 8 3 1 5 M H z - 8 . 8 2 9 5
M H z =
1 4 . 0 0 2 MHz)
This means that a signal 1 7 kHz In bandwldth
I S
received
wlth a shift of
+
5 0 0 Hz.
I n other words, the filter
characteristics have been changed appropriately
As you may have noted in Examples 1 and
2,
the V.BT and IF
SHIFT controls operate separately Therefore, it
IS
possrble
to control the bandwidth alone whlle keeping the IF SHIFT
unchanged, or control IF SHIFT while keeping the bandwldth
unchanged
3. NOTCH [in IF unit (X48-1290-00)
1
4
7
Thls
IS
a brtdged-T filter consisting of L, C, and R components.
The notch
I S
provlded In the 4 5 5 kHz IF Normally, the width
of the null would be broad at 4 5 5 kHz. Actually a sharp
notch is provlded by adding an active circuit which applies
posltive feedback to raise the Q. Q 5 and 0 6 (2SC1815Y)
are a Q-multiplier
Q7 ( 2 S C 1 8 1 5Y) is a buffer ampllfier
4. Speech processor [in IF unit (X48-1290-00) ]
& Y
T ~ I S speech processor
I S
an RF c l ~ p p e r The recelver uses
t w o Intermediate frequencles and t w o filters for VBT
In the
venlenr for lnstalllng RF clippers between the stages. The
4 5 5 kHz SSB signal is clipped and then c0nverte.d to an 8 . 8 3
M l i z signal, and then routed through an 8.83 M H z SSB filter
to remove splatter components generated during clipplng
Q 2 4 (2SC1815Y) is a processor amplifier, Q 2 6 (TA7302P) a
llmitlng amplifier, Q 2 7 (3SK73GR)
a
control ampllfier, and
Q 2 5 (2SC1815Y) and Q37 ( 2 S A 1 0 1 5 Y ) compose
a
com-
presslon meter amplifier The compresslon meter reads the
mean compresston level.
5.
Final-stage RF NFB
Negatlve feedback
IS
applled to the drlver from the final out-
pul stage via C6, a 3PF. 3KV capacitor to reduce Inter-
modulation distortion.
6. R IT/XIT Operations
In addition to the conventional RIT, the transmission frequen-
cy can be varled wrth the XIT control
TS-830s (K) AC Voltage conversion
To operate the T S - 8 3 0 s ( K ) on 2 4 0 V AC, the power
transformer split primaries must be rewired from parallel t o
series connection
1 . Unplug the AC power cable.
2 Remove the bottom cover
3 . Remove the jumper wires between the t w o
4
terminals
and t w o 1 2 0 terminals o n the bottom of the power
transformer.
4 . Connect the adjacent 1 2 0 and
4
terminals at the middle
of the transformer. 'This will provide 240V AC operation.
For 220V AC operation, change the wires from 1 2 0 to
1 0 0 winding.
5. Change the AC fuse from 6 A to 4A. Tag the power cord
at the back of the radio to indicate that the transformer is
strapped for 2 4 0 V AC, and the power fuse should be 4A.
and not 6A.
6. Replace .the bottom cover and reconnect power to verify
your work.
FAN MOTOR
(iOOV)
I T E
POWER SW
transmltter, an SSB slgnal
IS
generated at 4 5 5 kHz,
IS
con-
&
verted to 8 8 3 0 kHz, and passed through an SSB 8 . 8 3 M H z
filter after frequency conversion
Thls configuration
I S
con-
Hide quick links:
Table of Contents
