SDR or Analog?
Barry D. Jacobson
While the FTDX101 is marketed as a hybrid SDR, I believe this refers to the band spectrum display. There are some advantages to sound quality in analog receivers because the digitizing process creates a stair-step approximation to the signal, rather than a smooth curve. My understanding is that a complete SDR (direct digital synthesis, DDS) system would not require an IF at all, as all filtering can be done digitally, right off the digitized RF signal. Yet the FTDX101 has an IF, and the VC tune seems to be analog with actual variable capacitors controlled by a motor. On the other hand, some filtering seems to be done using DSP, like IF width, and various noise reduction processing. Can anybody explain the architecture and whether the main signal chain is analog or digital or some mix? If digital, how does received voice quality compare to older analog radios?