Re: [Discuss-gnuradio] Inconsistant Gain in X310

2014-11-25 Thread Daigle, Andrew - 1008 - MITLL
:58 PM To: discuss-gnuradio@gnu.org Subject: Re: [Discuss-gnuradio] Inconsistant Gain in X310 On 11/24/2014 10:26 AM, Daigle, Andrew - 1008 - MITLL wrote: Ben, I have tried injecting both a 50.0 MHz and a 50.1 MHz tone and setting the USRP with a center frequency of 50 MHz and a sampling rate

Re: [Discuss-gnuradio] Inconsistant Gain in X310

2014-11-24 Thread Marcus D. Leech
:36 PM *To:* Daigle, Andrew - 1008 - MITLL *Cc:* discuss-gnuradio@gnu.org *Subject:* Re: [Discuss-gnuradio] Inconsistant Gain in X310 Hi Andrew - What you describe is very strange. There is nothing in the USRP that changes dynamically based on the input power level (there isn't even AGC). The only

Re: [Discuss-gnuradio] Inconsistant Gain in X310

2014-11-22 Thread Louis Brown
Ben, I used set_auto_dc_offset(0) and that make things work correctly with the X310+LFRX. I noticed in the osmocom source the DC offset mode can be set. So what I'll do is run it in auto to get the initial correction, halt the flow, then run it in manual, and it uses the previously found

[Discuss-gnuradio] Inconsistant Gain in X310

2014-11-21 Thread Daigle, Andrew - 1008 - MITLL
Hello, I am running into a small issue with the X310 USRP. My basic setup involves receiving from two antennas (or at this point CW tones from signal generators) using two basic RX daughter cards. My problem is that when I pump in a -50 dBm CW tone to channel A the FFT plot makes sense in

Re: [Discuss-gnuradio] Inconsistant Gain in X310

2014-11-21 Thread madengr
Might want to post this over on the Ettus list, as I am having issue with the X310 and LFRX and have a few threads on there with examples of diagnosing it. The DC compensation seems to be always on (bad since the LRFX is DC coupled), and the digital gain setting seems broke. These may be related

Re: [Discuss-gnuradio] Inconsistant Gain in X310

2014-11-21 Thread Ben Hilburn
Hi Lou - By default, the RX DC offset is enabled. You can disable it with a quick multi_usrp call: http://files.ettus.com/manual/classuhd_1_1usrp_1_1multi__usrp.html#a7beb49c1a04a81b3e7569db482453746 Cheers, Ben On Fri, Nov 21, 2014 at 10:08 AM, madengr rfeng...@me.com wrote: Might want to

Re: [Discuss-gnuradio] Inconsistant Gain in X310

2014-11-21 Thread Ben Hilburn
Hi Andrew - What you describe is very strange. There is nothing in the USRP that changes dynamically based on the input power level (there isn't even AGC). The only thing I can think of is that somehow the built-in DC offset calibration is going haywire. Are you setting the center frequency

Re: [Discuss-gnuradio] Inconsistant Gain in X310

2014-11-21 Thread Marcus D. Leech
On 11/21/2014 10:17 AM, Daigle, Andrew - 1008 - MITLL wrote: Hello, I am running into a small issue with the X310 USRP. My basic setup involves receiving from two antennas (or at this point CW tones from signal generators) using two basic RX daughter cards. My problem is that when I pump