Icom IC-251A Instruction Manual page 12

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TUNING SPEED (TS) and TONE CALL 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 digits are 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 smali vernier marks will again correspond to 5KHz 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 in
SSB and CW, and to tune in FM signals which are off from 5KHz-step frequencies.
When the DIAL LOCK Switch is set in the ON position, this button operates as the TONE
CALL Switch. (1C-251E only)
Most repeaters require a 1750Hz Tone-burst for initial access. In the transmitting mode,
by depressing the Tone Call Switch for the required period for a repeater, the tone burst
generator actuates and you can access the repeater.
MEMORY SCAN START/STOP & MEMORY WRITE (MS/MW) BUTTON
The following three functions are provided by pushing the MS/MW Button.
MEMORY WRITE Writing a frequency into Memory Channel 1, [2], or [3].
SCAN START Starting the "A" and ''B" 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 5KHz 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 or CW mode, use the
TUNING SPEED Button.
When the operating frequency needs to be locked, use the DIAL LOCK Switch.
MULTI-FUNCTION METER