Icom IC-R8600 - Other Functions; Antenna Selection and AGC Control

5
OTHER FUNCTIONS
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5-1
Preamplier
About the Function screen
A preamplier is used when receiving weak signals.
LEach band memorizes the preamplier setting.
z Push [P.AMP] on the Function screen.
L Each touch turns the preamp ON or OFF.
On the Function screen, you can congure the
settings of various functions for each receiving mode.
1. Push to open the Function screen.
2. Touch (or touch for 1 second) a function key.
• Each touch turns the function ON or OFF.
• Each long touch selects an option for the
function.
L The usable functions differ, depending on the
receiving mode.
3. Push to close the Function screen.
NOTE:
The gain of preamplier is approximately 20 dB on
the HF bands, 14 dB on the VHF and UHF bands.
When you use the preamplier while receiving a
strong signal, the receiving signal may be distorted.
In such case, turn OFF the preamplier.
Attenuator
The Attenuator prevents a desired signal from
becoming distorted when a very strong signal is near
the frequency, or when a very strong electric eld.
LEach band memorizes the Attenuator setting.
z Touch [ATT] on the Function screen, to turn ON the
Attenuator.
L Each touch changes the attenuation between 10 dB
(ATT10), 20 dB (ATT20), 30 dB (ATT30) and OFF (no
indication).
L If a strong signal is received and
(Overow) appears,
reduce the RF gain or turn ON the attenuator until
disappears.
Function screen example (in the CW mode)
The AGC (Automatic Gain Control) produces a
constant audio output level, even when the received
signal strength varies greatly.
The receiver has 3 preset AGC settings (time
constants: FAST, MID and SLOW) for all modes
except the FM and DIGITAL mode.
1. Select the operating mode. (Example: SSB)
2. Push
to open the FUNCTION screen.
3. Touch [AGC] to select an AGC setting.
• Each touch changes the attenuation between FAST
("AGC-F"), MID and SLOW.
L
The AGC is xed to "FAST" in the FM, WFM or Digital mode.
4. To close the FUNCTION screen,
EXIT
.
You can change the preset AGC time constant:
1.
On the FUNCTION screen, touch [AGC] for 1 second.
2. Touch either FAST, MID or SLOW.
3. Touch an AGC preset you want to change the time
constant. (Example: MID)
4. Rotate to set the time constant.
L The adjustable time constants are described in the
table below.
5. To close the AGC screen, push
EXIT
.
• Selectable AGC Time constant (unit: seconds)
Mode Default Adjustable time constant
SSB
0.3 (FAST)
OFF, 0.1, 0.2, 0.3, 0.5, 0.8, 1.2,
1.6, 2.0, 2.5, 3.0, 4.0, 5.0 or 6.0
2.0 (MID)
6.0 (SLOW)
CW/FSK
0.1 (FAST)
OFF, 0.1, 0.2, 0.3, 0.5, 0.8, 1.2,
1.6, 2.0, 2.5, 3.0, 4.0, 5.0 or 6.0
0.5 (MID)
1.2 (SLOW)
AM
3.0 (FAST)
OFF, 0.3, 0.5, 0.8, 1.2, 1.6, 2.0,
2.5, 3.0, 4.0, 5.0, 6.0, 7.0 or 8.0
5.0 (MID)
7.0 (SLOW)
FM/WFM/
DIGITAL
0.1 (FAST) Fixed
AGC screen (in the SSB mode)
You can reset
to the default
settings by
touching this key
for 1 second.
AGC function control
NOTE: When you are receiving weak signals, and a strong
signal is momentarily received, the AGC function quickly
reduces the receiver gain. When that signal disappears, the
receiver may not receive the weak signal because of the AGC
action. In that case, select FAST, or turn OFF the AGC function.
Selecting the antenna
You can use either ANT1, ANT2, or ANT3 for receiving
below 30 MHz.
1. Rotate to set a frequency to below
30 MHz (10 kHz ~ 29.999999 MHz).
2. Touch the antenna connector indicator.
• Each touch changes the selected antenna connector.
L Next time you set the same frequency, the same
antenna connector is automatically selected.