ICOM 217800 Manuale Utente

4

1

PANEL DESCRIPTION

➥Activates or selects fast, middle or slow

AGC time constant when pushed. (p. 59)

• “FAST” is only available for FM mode.

➥Enters the AGC set mode when pushed

for 1 sec. (p. 59)

AGC time constant can be set between 0.1 to

8.0 sec. 

(depends on mode)

, or turned OFF. While

“OFF” is selected, the S-meter does not function.

✔

The AGC controls receiver gain to produce a constant audio
output level, even when the received signal strength is varied
by fading, etc. Select “FAST” for tuning and select “MID” or
“SLOW” depending on the receiving condition.

➥Turns the VOX function ON and OFF

when pushed in a phone mode (SSB, AM
or FM mode). (p. 65)

➥Enters the VOX set mode when pushed

for 1 sec. in a phone mode. (p. 65)

✔

The VOX function (voice operated transmission) starts trans-
mission without pushing the transmit switch or PTT switch
when you speak into the microphone; then, automatically re-
turns to receive when you stop speaking.

➥Selects semi break-in, full break-in oper-

ation, or turns the break-in operation
OFF when pushed in CW mode. (p. 66)

✔

The break-in function switches transmit and receive with CW
keying. Full break-in (QSK) can monitor the receive signal
during keying.

➥Turns the RTTY filter ON and OFF in

RTTY mode. (p. 45)

• When the RTTY filter is turned ON, [TWIN

PBT] functions as the IF shift control.

➥Enters the RTTY filter set mode when

pushed for 1 sec. in RTTY mode. (p. 45)

✔

The IF shift function electronically changes the center of the
IF (Intermediate Frequency) passband frequency to reject in-
terference. Only the inner control of [TWIN PBT] can be used
for the IF shift control.

➥Turns the speech compressor ON and

OFF in SSB mode. (p. 67)

➥Switches the narrow, middle or wide

transmit filter when pushed for 1 sec.

✔

The speech compressor compresses the transmitter audio
input to increase the average audio output level. Therefore,
talk power is increased. This function is effective for long dis-
tance communication or when propagation conditions are
poor.

➥Turns the 

1

⁄

4

function ON and OFF in

SSB data, CW and RTTY modes. (p. 27)

•

1

⁄

4

function sets dial rotation to 

1

⁄

4

of normal

for fine tuning.

➥Switches the tone encoder, tone squelch

function and no tone operation when
pushed in FM mode. (pgs. 52, 53

➥Enters the tone set mode when pushed

for 1 sec. in FM mode. (pgs. 52, 53)

!7

(outer control; p. 64)
Adjusts the noise reduction level when the noise re-
duction is in use. Set for maximum readability.

• To activate this control, turn the noise reduction ON in

advance (

!8).

!8

(p. 64)

Push to switch the noise reduction ON and OFF.

• The [NR] indicator in this switch lights green when the

function is activated.

!9

(p. 62)

➥Switches the noise blanker ON and OFF when

pushed. The noise blanker reduces pulse-type
noise such as that generated by automobile igni-
tion systems. This function cannot be used for
FM, or non-pulse-type noise.

• The [NB] indicator in this switch lights green when the

function is activated.

➥Enters the noise blanker level set mode when

pushed for 1 sec.

@0

(inner control; p. 63)

Adjusts the audio output balance between main and
sub readout frequencies while in dualwatch.

Increases main
readout gain

Increases sub
readout gain

Noise blanker OFF

Noise blanker ON

Noise reduction OFF

Noise reduction ON

Decreases

OFF

Increases

TONE

TONE

OFF

OFF

1/4

1/4
OFF

OFF

COMP

COMP

OFF

OFF

WIDE

WIDE

RTTY

RTTY

FIL

FIL
OFF

OFF

BK-IN

BK-IN

OFF

OFF

VOX

VOX
OFF

OFF

AGC

AGC
MID

MID