Icom IC-251A Instruction Manual page 16

= 14—
37.
38.
39.
40.
41.
42.
43.
SWR SWITCH
When measuring SWR, calibration SET and SWR reading functions are selected with this
switch. Remember, at the factory, the switch is in the SET position and fixed in place with a
plastic screw to prevent it from switching to SWR. Remove the screw before attempting to
read SWR!
SWR SET CONTROL
This control calibrates the meter needle to the SET position when you want to determine
the value of SWR. The set must be transmitting a carrier, then adjust the control until the
meter needle reaches the SET point.
CW MONI (MONITOR) CONTROL
This control adjusts the audio volume of the side tone (monitor) audio during CW transmit
operation. Adjust it to your desired level for easy listening.
CW DELAY (CW time delay constant) CONTROL
In semi-break-in CW operation, this controls the TX/RX switchover time delay. Adjust it to
suit you keying speed.
VOX GAIN CONTROL 7
This control adjusts input signal level via the microphone to the VOX circuit. For VOX
operation in SSB, adjust the control so that the VOX circuit will operate with normal speech.
VOX DELAY (VOX time constant) CONTROL ;
This controls the TX to RX switching time. Adjust it so TX to RX switching will not occur
during short pauses in normal speech.
ANT! VOX CONTROL
In VOX (SSB) operation, the VOX circuit may operate by sound from the speaker causing a
switch to transmit. This trouble can be prevented by adjusting the input level of the ANTI
VOX circuit with this control, along with the VOX gain control so that the VOX circuit only
operates from the operator's voice, not by sound from the speaker.