Icom IC-7200 Instruction Manual - Page 51

5 FUNCTIONS FOR RECEIVE ■ Twin PBT operation The general PBT (Passband Tuning) function electronically narrows the IF passband width by shifting the IF frequency slightly outside of the IF filter passband to reject interference. This transceiver uses the DSP circuit for the PBT function. By rotating both [TWIN PBT] controls (inner/outer; PBT1 and PBT2) with the same position, PBT functions as an IF shift control. The limit of the variable range depends on the passband width and mode. The limit of the variable range is half of the passband width, and PBT is adjustable in 200 Hz (AM) or 50 Hz (other models) steps. MODE TS TUNER FILTER SPCH NB NR ANF METER V/M 1 1.8 A=/B 2 3.5 SPLIT 3 7 MW 4 10 M-CL 5 14 AGC 6 18 COMP271 RIT . GENE SCAN 8 24 MNF 0 50 VOX 9 28 F-INP ENT BAND P.AMP ATT M-CH/RIT SET [TWIN PBT] • The [TWIN PBT] controls should normally be set to the center positions (PBT setting is cleared) when there is no interference. • When PBT is used, the audio tone may be changed. • While rotating the [TWIN PBT] controls, noise may occur. This comes from the DSP unit and does not indicate an equipment malfunction. PBT OPERATION EXAMPLE Both controls at center position TWIN PBT Cutting the lower passband TWIN PBT Cutting both higher and lower passbands TWIN PBT Passband Passband IF center frequency Interference Desired signal Interference Interference Desired signal 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 46