Jeff, >>From my perspective, the SDR1K has, essentially, two gain controls. > Conceptually, from the point of view of signal flow, I picture these two > gains as "pre-agc gain" and "post-agc gain." That is, the gain applied to > a > signal *before* it's attenuated by AGC, and the gain applied to a signal > *after* it's been attenuated by AGC. >
Well, sort of true. But it is more subtle than that. In a DSP engine it is possible to adjust many aspects of the AGC in a way that was not possible before. You simply have to re-think the concepts of RF Gain when working with DSP. It is just way to involved to try and discuss here on the reflector. I suggest two things. First read the TT description of DSP AGC on page 44 to page 48 of this document. They have titled it Weak Signal and Contest Operation, but it is really a discussion of how DSP engine AGC parameters interact: http://radio.tentec.com/cms-files/566_manual_release3_0306.pdf. Then I would like to hear from Frank and Bob on this topic and get their take on all this. I suspect that they have implemented the AGC functions in much the same way as Doug Smith did, and that the reference I quoted applies most directly to the Flex as well as to the Orion. >"RF Gain" is more intuitive. > > Or, perhaps more importantly, if there was a control on the front panel > labeled "Max AGC Gain," would this turn-off, rather than attract, > potential > buyers of the radio? > Well, by this time, everyone knows where I stand on this sort of discussion. To me, this is not a marketing issue. We are talking about how to allow users of the rig (that have already bought and paid for it) to extract the maximum performance from the system. You are only going to get maximum AGC performance in critical listening situations by having ready access to and understanding, technically, how to adjust all the DSP engines AGC parameters. It is that simple. I wish that you could, in fact, put a simple control on the front panel, call it RF Gain, and have it perform some sort of magic in all situations. But that isn't going to happen. As far as the "more intuitive", my response is that we all must keep learning new things until the day we die. When I learned to drive it was with a stick shift. When I bought my first car with an automatic transmission it was not intuitive to operate a car with out a clutch, but I learned. Hams new to DSP radios are going to have to learn a few new things. The intuitive part comes with practice. -Dan _______________________________________________ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
