appendix preselector rx stage characteristics
The FT-991/A Technical Supplement does not specify the bandwidth of the first input preselector for HF/6m, VHF & UHF bands. This is the result of the simulation LTSpice simulation of the Schematic Preselector filter for each band.
Click the images to see in full screen.
Figure 1 - FT-991 / FT911A Input HF/6m, VHF and UHF Schematic - click to enlarge
Figure 2 - FT-991 / FT-991A HF Low-Pass Filter - click to enlarge
Figure 3 - FT-991 / FT-991A VHF Band-Pass Filter - click to enlarge
Figure 4 - FT-991 / FT-991A UHF Band-Pass Filter - click to enlarge
Figure 5 - FT-991 / FT-991A HF band band-pass selectable filters - click to enlarge