Icom IC-471H Instruction Manual page 8

10. MIC GAIN CONTROL
Adjusts the level of modulation according to the input of tlie
microphone. As the input will vary with different micro-
phones and different voices, adjust for proper modulation
accordingly. Clockwise rotation increases mic gain.
11. RF POWER CONTROL
The 1C-471H has an output power of 10 ~ 75 watts which
can be varied by the RF POWER control. Turning the
control clockwise increases the power, while turning
counterclockwise decreases it.
12. VOX SWITCH
This switches the VOX circuit ON and OFF. When it is in
the ON (in) position, in SSB, T/R switching is accomplished
by means of a voice signal. In CW operation, semi-break-in
switching by means of keying is possible.
13. NB (NOISE BLANKER) SWITCH
When pulse type noise such as automobile ignition noise is
present, push this switch. The noise will be reduced to
provide comfortable reception. |
To turn off the noise blanker, push this switch again and
release it.
14. AGC (AUTOMATIC GAIN CONTROL) SWITCH
With this switch you can select the time constant of the
AGC circuit. With the switch in the out position, the AGC
voltage is released slowly, and is suitable for SSB reception.
With switch in the locked in position, the AGC voltage is
released faster, and the AGC is suitable for stations suffer-
ing from fast fading or when operating in the CW mode.
15. METER SWITCH
When this switch is pushed in the FM receive mode, the
meter functions as a discriminator meter.
16. PREAMPLIFIER SWITCH
When the optional mast-mounting preamplifier, AG-35, is
installed, this switch turns the preamplifier ON/OFF.
17. MODE SELECTIVE SCAN SWITCH
When this switch is pushed, only memory channels stored
. with the operating mode which is displayed on the fre-
quency display just prior to pushing this switch, are selected
by turning the tuning control or scanning.
18. OFFSET WRITE BUTTON
By pushing this button, the offset frequency is displayed
on the frequency display. In the FM mode, while this
button is depressed, the offset can be reset with 10KHz
steps by turning the tuning control.
19. CHECK BUTTON
Depressing this button allows reception on the programmed
"TX" frequency and causes the TX frequency to be dis-
played as long as the button is depressed.
20. +DUPLEX BUTTON
Pushing this button places, the set in the duplex mode with
eu cs
the transmit frequency set 5.0MHz (European version
7.6MHz) (This can be changed to any 10KHz steps in-band
frequency.) above the displayed receive frequency. To turn
off duplex, push this button again.
21. -DUPLEX BUTTON
Pushing this button places, the set in the duplex mode with
the transmit frequency set 5.0MHz (European version
7.6MHz) (This can be changed in 10KHz steps.) below the
displayed receive frequency. To turn off duplex, push this
button again.
22. TONE ENCODER SWITCH
U.S.A. version: Turns ON/OFF the built-in subaudible tone
encoder or the optional encoder/decoder.
European version: Puts the set in the transmit mode and
actuates the tone-burst generator.
23. TONE SELECT BUTTON
Selects the frequency of the subaudible tone encoder/
decoder. While this button is depressed, a code number is
displayed on the frequency display, and this number can be
changed by turning the tuning control. (U.S.A. version only)
24. METER
Functions as a relative RF output meter in the transmit
mode, and as an S-meter (signal strength meter) in the
receive mode. When the meter switch is pushed in, the
meter functions as a discriminator meter in the FM receive
mode.
25. TUNING CONTROL
Rotating this control clockwise increases the frequency or
the memory channel number, while rotating it counterclock-
wise decreases it. The frequency changes by 10Hz in SSB
and CW modes, and 5KHz in FM mode. In the 10Hz step
tuning rate, by turning the tuning control faster, the 100Hz
step tuning rate is automatically selected. This makes it
very convenient to make a QSY over a wide frequency
range.
This control is also used to reset the offset frequency and
to select the subaudible tone frequency.
26. DIAL LOCK AND SPEECH SWITCH
After the IC-471H is set to a certain frequency for rag
chewing, mobile operation, etc., by pushing this switch, the
VFO is electronically locked at the displayed frequency,
thus inactivating the operation of the tuning control. To
change frequency, the dial lock must first be disengaged by
pushing and releasing this switch again.
In addition, this switch functions as a switch to turn on the
optional speech synthesizer which announces the displayed
frequency in English.
27. TUNING RATE SWITCH
By pushing in this switch, the operating frequency is
changed to correspond to 1KHz increments in any mode.