Kenwood TS-830S Instruction Manual page 15

(2) RF GAIN CONTROL
RF GAIN is controlled by changing the AGC threshold
voltage. Adjust the RF GAIN so the S-meter does not
deflect excessively. This also reduces noise during
reception. For normal operation, this control should be turn-
ed fully clockwise for maximum sensitivity.
Maximum "S" meter reading of
an incoming signal
AF RF
GaIN~®— GAIN
fo
o Full
Signals weaker Pointer deflection with Clockwise
than this level —, , RF gain control adjusted position
| F
7 GAIN
yh
|
'
v ay | fy yi 8
counter
clockwise
Fig. 4-3 RF GAIN Control Operation
conjunction with the IF SHIFT and NOTCH filter to obtain
optimum results, By setting the VBT control to the
NORMAL position, maximum passband-width is obtained.
The IF filter passband-width is narrowed as the control is
adjusted counterclockwise, while center frequency remains
unchanged. Fig. 4-4 illustrates operation. The range of
variability depends on the type of optional filter used.
(i) When the filter bandwidth is 2.4 kHz (without an option-
al filter), the passband-width varies within the range of
500 Hz to 2.4 kHz. See Fig. 4-4A.
(ii) With an optional YK-88C filter (8.83 MHz, 500 Hz
bandwidth) or YG-455C filter (455 kHz, 500 Hz
bandwidth), the passband-width varies from 500 Hz to
approximatly 150 Hz.
Since an optional filter center frequency is 700 Hz
higher than that of the built-in 2.4 kHz filter, the CW
receive tone will be about 800 Hz without using the IF
shift. Fig. 4-4A shows the VBT function with an
optional filter.
(3) AGC (AUTOMATIC GAIN CONTROL)
Set the AGC switch to the appropriate position: Generally
for SSB, SLOW, for CW FAST, and for very weak signals, the
AGC may be turned OFF.
Simultaneous Use of the RF GAIN CONTROL and AGC
Switch
If a strong signal (such as a local station) appears in the vici-
nity of the intended receive signal, the S meter may show
unusual deflection due to the AGC voltage developed from
the strong disturbing signal. If this occurs, turn the RF GAIN
down so the meter pointer remains at about the original
deflection peak and turn the AGC switch OFF. This will
eliminate the unwanted AGC voltage and permit clear
reception.
(4) RIT/XIT
First set the RIT/XIT control to center, and turn the RIT
switch ON.
The RIT/XIT control allows shifting the receive frequency by
approximately +2 kHz without changing the transmit
frequency.
With the RIT switch ON, the receive frequency can be
adjusted by using the RIT control.
With both the RIT and XIT switches ON, both the transmit
and receive frequencies can be shifted.
For XIT switch operation, refer to Section 4.4 Transmission
(II)
NOTE:
When the RIT is ON, transmit frequency is different from the
receive
frequency. For normal
operation,
leave the RIT
switch OFF. It should be turned ON only when needed.
This control is used to eliminate radio interference by
changing the IF passband-width. Use this control in
08 2.4(kHz) 500 (Hz)
(A) USB.LSB mode (B) CW 500 tz filter
Fig. 4-4A VBT Control Positioning
455 kHz filter
Sasso
8.83 MHz filter
3 2
S
é 3
aot Cc
3 &
a b a
a =
o ao
ao &> 2
D> g
GS? z..
3 FA
gs 4
Es
Ss
Ee
20
SSASAY
bess
NARROW NORMAL NARROW NORMAL.
Fig. 4-4B VBT Selectivity Characteristics
15