Kenwood TS-990S - Manual (Page 82)

5-4
5 ASSISTING YOUR SMOOTH QSO
Index Contents
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.
■ DEFAULTS OF AGC TIME CONSTANT (COMMON TO
MAIN BAND AND SUB BAND)
Mode Time Constant Display
SSB SLOW
AGC-S
SSB-DATA SLOW
CW FAST
AGC-F FSK FAST
PSK FAST
AM SLOW
AGC-S
AM-DATA SLOW
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”.
[F1] [F7]
[MULTI/CH]
[ESC]
[AGC/SEL](S)
[AGC/SEL](M)
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
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 MID SLOW
SSM 9 12 15
SSB-DATA 9 12 14
CW 9 12 14
FSK 7 11 14
PSK 7 11 14
AM 9 13 16
AM-DATA 9 13 16
• 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).