Bill, all of the Elmers must be nursing a hangover from the weekend. Here is a brochure with a high level overview of the 6x series front-end.
The essential point is the following excerpt:
"The FLEX-6700 and FLEX-6700R incorporate two independent, synchronous Analog Devices AD9467 16-bit 245.76 Msps (Mega samples per second) analog to digital converters"
Thus, the SCUs directly sample the RF signal (pehaps, after prescale/preamplification), and then feed this massive amount of digital data into an FPGA where begins its SDR journey.
Picture an SCU (Spectral Capture Unite) as a high powered analog-to-digital converter that captures a wide amount of spectrum (0 - 74 Mhz) right from the antenna port all at the same time and converts it to digital.
The other processors in the 6000 series are able to manipulate this digital information and provide multiple 14 MHz wide (on the 6500 & 6700) or 7 MHz wide (on the 6300) panadapter displays anywhere in this captured spectrum. The rig can also select 8, 4 or 2 (depending upon the rig) different "Slices" of that spectrum and process each one as a separate receiver channel (Up to 10 KHz wide) for am, ssb, cw, Digital modes, and soon, FM. These slices can be mixed or matched in any combination on the Panadapter displays.
The 6300 & 6500 have one SCU and can listen simultaneously to 2 or 4 different signals anywhere in the captured spectrum as long as they come from the same antenna feed.
The 6700 has TWO SCU's and beefier processors and can do the same thing on 8 pans/slices and the signals can come from TWO different antenna feeds. The advantage being you can have a 6 meter antenna on SCU#1 and a 160 Meter antenna on SCU#2...or you can have a vertical and a horizontal antenna on each input and have polarization diversity reception. Later software releases will be able to do other amazing things by mixing two different antenna sources via the 2 SCU's.
I hope this helps.
Ken - NM9P
I have already experienced that my 6300 can receive without a computer, but I would like to understand if doing so I can lost some of the FlexRig capabilities.