[USRP-users] problem with loopbacks when using USRP

Jason Matusiak jason at gardettoengineering.com
Tue Jul 28 12:01:28 EDT 2015

> No, the U's aren't OK to ignore.  That means you're under-running on the TX side, which means missing samples.  If 
> you're getting a lot of them, it means you aren't likely getting *any* good frames over the air.

OK, looks like I totally misunderstood that...  I was thinking that it
meant that I the transmitter was ready to send but I hadn't prepared a
new packet yet, which would be fine.  What is the cause/solution to the
underrun? I tried reducing the sample rate from 10MHz to 2MHz, but I am
still seeing occasional U's and D's. but not nearly as many as before. 
I'll play with it at this reduced rate to see if that help some, but I
am surprised that I had to reduce it so much for an X310.

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