Icom IC-821H Instruction Manual page 4

PANEL DESCRIPTION —
E Front panel
@ POWER SWITCH [POWER] (p. 15)
Turns power ON and OFF.
- Turn the optional DC power supply ON in advance.
're Power OFF
I-11 PowerON
@ TX/RX INDICATORS
e Light green while receiving a signal (and squelch
opens) on the main or sub band. Lights red while
transmitting.
- When ALC is activated, the transmit band's indicator
brightness increases. (p. 25)
e Flash green when the center indicator is turned
ON in set mode with the [FM] switch and an off-
center signal is received in FM mode. (p. 23)
What is the ALC function?
The ALC circuit automatically limits RF output power by
controlling the input level of the RF power amplifier. This
prevents transmission of distorted signals when the input
signal level exceeds the allowable level. The ALC acti-
vates for SSB and CW modes.
© AF CONTROLS [AF (MAIN)}/[AF (SuB)]
(inner control)
Vary the audio output level from the speaker.
AFSAL
Decreases 4 \ Increases
No audio output Max. audio output
See pgs. 3-6 See p. 7
@ SQUELCH CONTROLS [SQL (main)]/[SQL (suB)]
(outer control) (p. 21)
Adjust the squelch threshold level. The squelch re-
moves noise output from the speaker (closed con-
dition) when no signal is received.
- The squelch is particularly effective for FM. It is also
available for other modes.
- Squelch threshold point for SSB/CW mode can be set
to the 9 or 12 o'clock position in set mode with the
[CHECK] switch. (p. 45)
Recommended level for FM
ees
Shallow I \ Deep
Recommended level
for SSB and CW
How to set the squelch.
When operating in FM, first rotate the control fully coun-
terclockwise. Then, rotate the control clockwise to the
point where the noise just disappears. This is the opti-
mum position. The squelch does not open for weak sig-
nals when it is set too deep (clockwise).
© S/RF METER
Shows main band's signal strength while receiving.
Shows the relative output power while transmitting.