> Some follow-on questions: > > 1) When you say "The DSP outputs a voltage to control the IF gain of > the radio." are you referring to VIFGAIN1 input to U3B on the RF > board? >
Yes. > 2) Assuming so, is there anything that influences the voltage on > VIFGAIN1 other than on behalf of the RF gain pot, and is the voltage > appearing at VFGAIN1 on behalf of the RF gain pot "processed" away > from a linear replication of the pot wiper voltage? > Without staring at the DSP code to verify the veracity of my reply, I recall that the RF Gain control is the only thing that currently drives the VIFGAIN1 voltage. Subject to change, of course, since it is a DSP firmware function. And yes, the value read from the pot is processed by the DSP on its way to becoming VIFGAIN1. Again, the algorithm applied is subject to change. > 3) The hardware AGC appears to have fixed slope, attack and decay > constants. What would be the DSP slope and decay config constants to > mimic the hardware AGC constants? > Correct as to the first, and I think there may be that there are no settings that exactly mimic the HAGC. Their purposes are quite different. To the DSP, influences of the HAGC voltage on the received signal are treated no differently than changes in propagation. > 4) Is there a table that provides a dBm equivalent of each of the > threshold values? Or alternatively are the values on the Clifton Labs > site correct? > > ( 2 -117 dBm > 3 -110.5 dBm > 4 -105 dBm > 5 -103.5 dBm > 6 -102.5 dBm > 7 -101 dBm > 8 -99 dBm ) > There is no available table, and Jack's measurements were accurate at the time they were made for the then-current firmware release. 73, Lyle KK7P ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
