Icom IC-78 Instruction Manual - Page 22

4 OPERATION ï Meter peak hold The meter peak hold function freezes the highest displayed bar segment in any meter function for about 0.5 sec. so that you can more easily read the meter. This function can be turned ON and OFF in initial set mode. (p. 31) Initial reception of a signal results in an S-meter reading of 40 dB. The highest indicated bar remains displayed for 0.5 sec. even when the signal strength decreases. ï IF shift function The IF shift function electronically narrows the passband frequency of the IF (intermediate frequency) and cuts out higher or lower frequency components of the IF to reject interference. The function shifts the IF frequency up to ±1.2 KHz in SSB/CW/RTTY modes and up ±250 Hz in CW-narrow/RTTY narrow modes. The IF shift is not available in AM mode. IF SHIFT OPERATION EXAMPLE • Adjust the [SHIFT] control for a minimum interference signal level. •When IF shift is used, the audio tone may be changed. • Set the IF shift control to its center position when there is no interference. Both controls at center position Cutting a lower passband Cutting higher passbands SHIFT SHIFT SHIFT Interference Passband IF center frequency Desired signal Passband Interference Desired signal 20