Im trying to set the TX Gain of USRP device using the following command
while transmitting using uhd_siggen_gui tool:
./uhd_siggen_gui --sine -g <TX_Gain> -f 1013M --amplitude=1.0 -A TX/RX
-v
If I set the TX_Gain to non integer or non 0.5 fractional values, it is
getting set to nearest integer or 0.5 fractional values.
For example, if I set TX_Gain to 22.6, it will be set to 22.5 as shown
in
gui
Similary, setting TX_Gain to 22.1 will set it to 22, 19.9 will set it to
19.5 etc
But I can set the TX_Gain properly using the gui slider.
Any idea on how to set it properly using command line?
Thanks for the info. Can anybody please confirm whether the step size limit
of 0.5 dB is valid for USRP N200?
It’s not the underlying motherboard, it’s the daughter-cards. I think
all of WBX, SBX and CBX use a step attenuator with 0.5dB step size.
Others, I’m not sure about.
Generally, the “analog stuff” is on the daughtercards, and gain-setting
is definitely “analog stuff”.
If you need fine-grained control over output power, you can vary the
magnitude of your baseband signals, where you have much-finer
control available. Although, I have to admit that, except for
certain laboratory experiments, power-control beyond 0.5dB granularity
is of very little use in any practical sense.