Lee Patton wrote: > I don't understand why the gain range returned by the DBSRx ranges from > 0 to 104 when the PGA gives only 0 to 20 dB. Obviously, the answer lies > in db_dbs_rx.py, but I haven't a clue as to what the code is really > doing. Can anyone (Eric) explain? I read about Registers 2/3 in the > AD9862 data sheet, but I couldn't correlate that information with the > code. >
There are 2 components to gain control in the RX daughterboards: 1> The PGA gain, which ranges from 0-20 dB in 1 dB steps 2> The gain control amplifiers on the daughterboard itself. On the BasicRX there is no amplification, so you just get the PGA On the dbsrx there are 2 variable gain amps. One is controlled by an analog signal from the low-speed DAC output. The other is controlled digitally over the I2C port. On the TVRX there are separate IF and RF AGC amps, both are controlled by the low-speed DACs The FlexRF has a single AGC amp, again controlled by the low-speed DAC. Matt _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
