Nothing in the USRP will be damaged. It's up to you to ensure that your
subsequent RF chain will handle it. There are a few, rare configurations
which come to mind where it would be a Bad Thing to suddenly pulse power on
a millisecond timescale with extremely high bandwidth.

   1. Using your USRP to drive a linear accelerator (don't laugh, it's been
   done)
   2. Using your USRP to drive an extremely high power tube-based AM
   transmitter
   3. Using your USRP to drive an amplifier which is not unconditionally
   stable

Outside of these you're probably fine.

Nick

On Tue, Mar 3, 2020 at 3:21 PM Marcus D. Leech via USRP-users <
[email protected]> wrote:

> On 03/03/2020 06:16 PM, Sam Reiter via USRP-users wrote:
>
> Hey Francisco,
>
> Interesting question. I remember reading this when it was initially
> posted, giving it some thought, and promptly forgetting to respond. It's a
> question that is difficult to give a "yes" or "no" to. Similar to
> statistics, I think the answer to this question only comes by disproving
> the null hypothesis that "no part of the signal chain is damaged with an
> underflow". If you can't prove that damage will occur, then you're probably
> in the clear, but you also can't be positive that the null hypothesis is
> true. That being said, I don't think underflows are bad for the hardware in
> any way.
>
> An underflow is typically caused when a bottleneck on the host side
> prevents data from filling USRP buffers quickly enough to be pushed through
> the DAC at the requested rate. As I see it, the only place in the signal
> chain that *might* exhibit unexpected behavior in the face of samples not
> being present would be at the DAC (don't ask me why, but that would be my
> best guess). The way UHD operates, the DAC and ADC are initialized and
> running as soon as the streamer objects in UHD are initialized, and they
> sit there processing nothing (similar to an underflow state) until a TX
> stream command from the host tells the USRP radio core to release it's
> queued samples to the converter(s).
>
> Maybe that was all nonsense. In any case, I wouldn't worry about radio
> damage, I'd worry about fixing your underflows :)
>
> Best,
>
> Sam Reiter
>
> I'd have to agree with Sam here.
>
> An underflow on the TX will just mean that whatever the DAC last saw will
> be presented to the analog interface during the underflow period.
>   Which means perhaps a few microseconds of no level change coming out of
> the DAC.   Not a problem at all, as far as I know.
>
> The main thing is to optimize your code/computer-hardware to prevent them.
>
>
> _______________________________________________
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> [email protected]
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>
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