Chapter 7 Operating Aids; Receiving; Rit (Receive Incremental Tuning); Agc (Automatic Gain Control) - Kenwood TS-870S Instruction Manual

OPERATING AIDS

RECEIVING

RIT (RECEIVE INCREMENTAL TUNING)

RIT provides the ability to change your receive
frequency by ±9.99 kHz in steps of 10 Hz without
changing your transmit frequency. If the Fine Tuning
([FINE]) function is ON, the step size is 1 Hz. RIT
works equally well with all modulation modes and while
using VFO mode or Memory Recall mode.
It's a good habit to switch OFF the RIT function after a
contact is finished. This returns the receive frequency
to the transmit frequency. It ensures that you don't
listen by mistake on a different frequency from your
transmit frequency on the next contact. When using
Memory Recall mode, RIT only functions with a memory
channel containing stored data. Since an empty
channel contains no receive frequency, RIT cannot
function.
1 Press [RIT].
• "RIT" and the RIT frequency display appear.
AGC AUTO
USB
2 Press [CLEAR] to reset, if required, the RIT offset
to 0.
3 Turn the RIT/XIT control to change your receive
frequency.
AGC AUTO
USB
4 To cancel the RIT function, press [RIT].
The frequency shift set by the
Note:
the XIT function.

AGC (AUTOMATIC GAIN CONTROL)

The AGC function selects the time constant for the
automatic gain control circuit. Selecting a slow time
constant will cause the receiver gain and S-meter
readings to react slowly to large input changes. A fast
time constant causes the receiver gain and the S-meter
to react quickly to changes in the input signal. A fast
AGC setting is particularly useful in the following
situations:
• Tuning rapidly
• Receiving weak signals
• Receiving high-speed CW
44
SPLIT
RIT
SPLIT
RIT
control is also used by
RIT/XIT
The TS-870S will take charge of setting the AGC, using
independent release times that you specify for each
mode. Or, you can have total control by manually
adjusting the AGC yourself from the Front Panel. When
receiving strong signals in AM mode with the AGC OFF,
the clipping action will make reception difficult or
impossible.
To select whether you want Automatic or Manual
control, use Menu No. 01 (AUT/MAN). Select OFF for
Manual control and ON for Automatic control. The
default is Manual (OFF).

■ Changing AGC

Automatic (Menu No. 01 (AUT/MAN) is ON):
The following Menu items are available to change
the AGC release time in Automatic mode:
Menu No.
Mode
02
SSB
03
CW
04
FSK
05
AM
Manual (Menu No. 01 (AUT/MAN) is OFF):
With Menu No. 01 (AUT/MAN) set to OFF, adjust the
AGC control to set the AGC release time as you
prefer.
• Turning the control clockwise selects a faster
release time and counterclockwise selects a
slower release time.
• To switch OFF the AGC completely, turn the AGC
control fully counterclockwise.

■ Changing AF AGC

The TS-870S offers further control of your receiver
AGC for the FM and AM modes. For these two
modes, you may adjust the AGC release time and
level in the AF stage.
Function Menu No.
AF AGC 06
Release
Time
AF AGC 07
Level
Selections
Default
OFF, 1 ~ 20 7
12
OFF, 1 ~ 20
14
OFF, 1 ~ 20
5
OFF, 1 ~ 20
Default
Selections
0: Slow
1: Med
1: Med
2: Fast
0: OFF
1: Min
1: Min
2: Med
3: High
4: Max