Icom IC-551D Instruction Manual page 12

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. The following three functions are provided by pushing the MS/MW Button. |
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TRANSMIT/RECEIVE (T/R) SWITCH
This switch is for manually switching from transmit to receive and vice versa. Set the switch
to RECEIVE (up) and the IC-551D is in the receive mode. Set the switch to TRANSMIT |
(down) 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.
VOX SWITCH |
This switches the VOX circuit ОМ and OFF. When the switch is іп the ON (down) position їп
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.
DIAL LOCK SWITCH
After the IC-551D is set to a certain frequency for rag chewing, mobile operation, etc., by
switching the DIAL LOCK Switch to the ON position (down), the VFO is electronically
locked at the displayed frequency, and this inactivates the operation of the Tuning Knob.
To change frequency, the Dial Lock must first be disengaged by setting the DIAL .LOCK
Switch to OFF (up) position.
TUNING SPEED (TS) BUTTON
Pushing the TUNING SPEED Button will illuminate the TS indicator LED, and the small
vernier marks on the Tuning Knob are changed to correspond to 1KHz increments in any
mode. At the same time, the 100Hz digit is cleared on the display to show "0" in the last
digit. When the Tuning Speed Button is depressed again, the TS indicator LED goes OFF and
the small vernier marks will again correspond to 10KHz steps in the FM mode and 100Hz
steps in all other modes. This button will allow you to quickly OSY over a great frequency
range їп 558, СМ and AM, and to tune in FM signals which are off from 10KHz-step
frequencies.
MEMORY SCAN START/STOP & MEMORY WRITE (MS/MW) BUTTON
MEMORY WRITE Writing a frequency into Memory Channel 1, [2], or [3].
SCAN START Starting the "А" and "В" scans and Memory Scan.
SCAN STOP Stopping any of the scan functions.
TUNING CONTROL KNOB
Rotating the Tuning Control Knob clockwise increases the frequency, while rotating it coun-
terclockwise decreases it. The frequency is changed in 100Hz steps (all modes except FM)
and 10KHz steps (FM mode) which correspond to the smaller vernier marks on the knob.
When the TUNING SPEED Button is pushed and the TS indicator LED is illuminated, the
frequency is changed in 1KHz steps, which correspond to the smaller vernier marks on the
knob, in all modes including FM.
By rotating the Tuning Control knob clockwise beyond the highest edge of the band the
operating frequency is automatically reverted to the lowest edge of the band, and vice versa.
This system prevents you from operating out of the amateur radio band.
When OSYing over a large frequency range is required in the SSB, CW or AM mode, use the
TUNING SPEED Button.
When the operating frequency needs to be locked, use the DIAL LOCK Switch.