Icom IC-730 Maintenance Manual page 5

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FRONT PANEL
1. MODE SWITCH
This switch selects the mode of operation for both transmit
and receive.
USB Upper Sideband, mainly for 10, 14, 18,21,24 and
28M Hz bands.
LSB Lower Sideband, mainly for 3.5 and 7MHz bands.
ON Continuous Wave, for CW operation on all bands.
CW-N Narrow ON. The narrow crystal filter is auto-
matically turned ON in this position to improve
selectivity when receiving. (When optional crystal
filter is installed).
AM Amplitude Modulation.
2. POWER SWITCH
The POWER SWITCH is a push-lock type switch which
controls the input DC power to the IC-730. When the
external AC power supply (lC-PS15) is used, the switch also
acts as the AC power supply switch. When the switch is
pushed in and locked, power is supplied to the set. When
the switch is pushed again and released, power is cut to all
circuits except the PA unit. (When the BC-10A is used,
power will also be supplied to the CPU.
3. MIC CONNECTOR
Connect the supplied microphone or optional microphone,
IC-SM5 or IC-HM10 to this jack. If you wish to use a dif-
ferent microphone.
4. PHONES JACK
Accepts a standard 1/4 inch headphone plug for headphones
'of 4 - 16 ohms. Stereo phones can be used without modi-
fication.
5. MIC GAIN CONTROL
Adjusts the level of modulation according to the input of
the microphone. Oockwise rotation increases the micro-
phones gain. As the input will vary with different micro-
phones and different voices, the knob should be turned until
the Meter needle, in the ALC mode, begins to move slightly
within the ALC zone. In SSB and AM modes, when the
speech processor is in use, the MIC GAIN CONTROL sets
the clipping limits, while the RF POWER CONTROL sets
the RF drive level to the maximum power level, where ALC
starts at the saturation point of the amplifiers.
6. RF POWER CONTROL
Controls the RF output power 10 Watts to maximum (SSB:
100 Watts PEP, CW: 100 Watts, AM: 40 Watts). Clockwise
rotation increases the output power.
7. AF GAIN CONTROL
Controls the audio output level in the receive mode. Clock-.
wise rotation increases the level.
8.
RF GAIN CONTROL
Controls the gain of the R F section in the receive mode.
Clockwise rotation gives the maximum gain.
As
the control
is rotated counterclockwise, the needle of the METER rises,
and only signals stronger than the level indicated by the
needle will be heard.
2-2
9. T/R (TRANSMIT/RECEIVE) SWITCH
This switch is for manually switching from transmit to
receive and vice versa. Set the switch to RECEIVE (out)
and the IC-730 is in the receive mode. Set the switch to
TRANSMIT (in) and it switches to transmit. When switch-
ing with the PTT switch on the microphone or with the
VOX switch set to ON, the T/R switch must be in the
R ECE IV E position.
10. 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 qf a voice signal. In CW operation, semi-break-in
switching by means of keying is possible.
11. NB (NOISE BLANKER) SWITCH
When pulse type noise such as automobile ignition noise is
present, set this switch to the ON (in) position. The noise
will be reduced to provide comfortable reception.
The blanking time can be selected NARROW and WIDE,
by the NB WIDTH switch under the access cover. It will be
effective against any type noises.
12. AGC (AUTOMATIC GAIN CONTROL) SWITCH
For changing the time-constant of the AGC circuit. With
the switch in the AGC position (out) the AGC voltage is
released slowly, and thus is suitable for SSB reception.
With the switch in the FAST (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.
13. PREAMP SWITCH
Switches the preamplifier for the receiver.
14. MEMORYNFO WRITE BUTTON
By pushing this button, A VFO's frequency is written into
Memory, or one VFO's frequency is transferred to the
other VFO.
15. MEMORY SWITCH
Push this switch when you wish to write a frequency into
memory, or to call a memorized frequency.
16. TUNING CONTROL KNOB
Rotating the TUNING CONTROL KNOB clockwise in-
creases the frequency, while rotating it counterclockwise
decreases the frequency. The frequency is changed in 10Hz,
100Hz or 1KHz steps which is according to the TUNING
RATE switches. One complete rotation of the tuning
knob results in a 1 KHz frequency increase or decrease in
10Hz steps, 10KHz in 100Hz steps and 100KHz in 1KHz
steps.
17. METER
When in the receive mode the meter acts as an S meter
regardless of the position of the meter select switch. Signal
strength is indicated on a scale of S1-S9, and S9 to
S9+6OdB.
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