I'm sorry, which thread are you referring to? I have tried implementing the changes in the thread I originally linked to and it doesn't seem to have made any difference.
Best, Thomas On Feb 25, 2018 4:52 AM, "Steven Knudsen" <ee.k...@gmail.com> wrote: > Hi, > > This is a known problem with the B20xmini. Have a look at this thread and > then follow it up. > > You are right, you are seeing caps charge and discharge, basically. > > Since I made the changes myself on my units, I am not sure where things > were left with Ettus and their policy for fixing the problem. But I can say > that once you make the changes, the transients are gone and the minis work > really well. > > regards, > > steven > > > On Sat, Feb 24, 2018 at 3:25 PM, Thomas Teisberg via USRP-users < > usrp-users@lists.ettus.com> wrote: > >> I'm working on a radar project that requires sending a series of short >> pulses. Looking at the pulses on a scope, I'm seeing large voltage spikes >> at the beginning and the end of each transmission. >> >> As shown in the attached screenshot, before the transmission starts, >> there is a 90 mV spike lasting about 10 us. After the transmission, there's >> a -25 mV spike lasting about 20 us. >> >> The setup for this is simply a USRP B205mini-i connected to a 50 ohm >> input on a scope through a 30 dB attenuator. The signal is at 435 MHz with >> the scope sampling at 20 Gsps. >> >> Our initial thought was that we must be seeing some effects of some of >> the RF frontend components turning on and off. I found this previous >> mailing list post and tried the suggested fix in b200_impl.cpp but nothing >> changed: >> >> http://lists.ettus.com/pipermail/usrp-users_lists.ettus.com/ >> 2015-January/012269.html >> >> Any ideas why we might be seeing these spikes or what we could do about >> it? Does the fix suggested in the above mailing list post still apply to >> the current codebase? >> >> Thanks, >> Thomas >> >> _______________________________________________ >> USRP-users mailing list >> USRP-users@lists.ettus.com >> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >> >> > > > -- > K. Steven Knudsen, Ph.D., P.Eng. >
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