Agc (Automatic Gain Control); Selecting The Agc Time Constant; Changing The Agc Time Constant - Kenwood TS-990S Instruction Manual

5 ASSISTING YOUR SMOOTH QSO
AGC (AUTOMATIC GAIN CONTROL)
AGC is a function that automatically controls the IF Gain
so as to absorb variations in the received signal strength.
Following the receiving state or the operating mode (other
than FM mode), FAST, MID, or SLOW can be configured
for the AGC time constant.
The digital AGC circuit of the transceiver is adjustable to a
SLOW, MID, or FAST value ranging from "1" (the quickest)
to "20" (the slowest).
In general, a fast time constant is configured for CW and
FSK modes where there is a rapid variation in the received
signal strength, and a slow time constant is configured for
SSB and AM mode where the variation is slower.
Fast time constant is effective for quick tuning when a
weak signal is present.
Also, you can disable the AGC. As shown below, a default
AGC time constant is set on a mode-by-mode basis.
■ D EFAULTS OF AGC TIME CONSTANT (COMMON TO
MAIN BAND AND SUB BAND)
Mode Time Constant
SSB
SSB-DATA
CW
FSK
PSK
AM
AM-DATA

SELECTING THE AGC TIME CONSTANT

Following are the procedure to switch the AGC time
constants of the main band and sub band to "FAST", "MID"
or "SLOW".
[MULTI/CH]
[ESC] [F1] [F7]
1 Press one of mode keys to select any mode other than
FM mode.
2 Press [AGC/SEL] (M) or [AGC/SEL] (S) to select the
AGC time constant.
Each time you press the key, the selection cycles as follows:
FAST > MID > SLOW > FAST
5-4
Display
SLOW
AGC-S
SLOW
FAST
FAST AGC-F
FAST
SLOW
AGC-S
SLOW
[AGC/SEL](S)
[AGC/SEL](M)

CHANGING THE AGC TIME CONSTANT

Time constant for the main band and sub band can be
independently changed from the defaults.
1 Press one of the mode keys to select any mode other
than FM mode.
2 Press and hold [AGC/SEL] (M) or [AGC/SEL] (S) to
open the AGC screen.
3 Press [AGC] (F3), [AGC/SEL] (M), or [AGC/SEL] (S)
to select "FAST", "MID", or "SLOW".
Pressing [AGC] (F3), [AGC/SEL] (M), or [AGC/SEL] (S)
while the AGC is disabled for the main band and sub band
enables the AGC.
4 Press [-] (F4) or [+] (F5), or rotate the MULTI/CH
control to select the AGC time constant.
• Selecting "1" enables the slowest AGC time constant, and
selecting "20" enables the fastest AGC time constant. The
defaults of the AGC time constants for each operating
modes are below.
Mode FAST
SSM 9
SSB-DATA 9
CW 9
FSK 7
PSK 7
AM 9
AM-DATA 9
• Press and hold [(RESET)] (F1) to reset the selected AGC
time constant to the default.
5 Press [ESC] to exit.
In FM mode, the AGC screen does not open even with a long
press of either [AGC/SEL] (M) or [AGC/SEL] (S).
MID SLOW
12 15
12 14
12 14
11 14
11 14
13 16
13 16
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