Icom IC-730 Maintenance Manual page 5

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
28MHz bands.
LSB Lower Sideband, mainly for 3.5 and 7M Hz bands.
CW Continuous Wave, for CW operation on all bands.
CW-N Narrow CW. The narrow crystal filter is auto-
matically turned ON in this position to improve
selectivity when receiving. (When optional crystal
filter 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 (IC-PS15) is used, the switch also
acts as the AC power suppl y switch. When the switch is
pushed in arid 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-H M10 to this jack. If you wish to use a different
microphone, refer to the drawing on page 4.
4. PHONES JACK
Accepts a standard 1/4-inch headphone plug for headphones of
4 ~ 16 ohms. Stereo phones can be used without modification.
5. MIC GAIN CONTROL
Adjusts the level of modulation according to the in put of the
microphone. Clockwise rotation increases the microphones gain.
As the in put will vary with different microphones 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 RF section in the receive mode.
Clockwise rotation gives the maximum gain. As the control
is rotated counterclockwise, the need le of the METER rises,
and only signals stronger than the level indicated by the
needle will be heard.
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 switching with
the PTT switch on the microphone or with the
VOX switch set to ON, the T/R switch must be in the
RECEIVE position.
10. VOX SWITCH
This switches the VOX circuit ON and OF F. 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.
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 suffering
from fast fading or when operating in the CW mode.
13. PREAMP SWITCH
Switches the preamplifier for the receiver.
14. MEMORY/VFO 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 1K Hz 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 + 60dB.
2 – 2