Re: [Discuss-gnuradio] sine output between packets

[Johnathan Corgan]

On Mon, Sep 26, 2011 at 05:36, Tom Rondeau <address@hidden> wrote:
> On Sun, Sep 25, 2011 at 8:07 AM, Brett L. Trotter <address@hidden>
> wrote:
>>
>> It seems my old patch that zeroed out the output of the USRP didn't make
>> it into UHD- we're seeing a constant sine output between packets- and in
>> our case this messes with the receiver unless we use some custom TX
>> cards that have an amp we can shut down with ATR.
>>
>> Is there any way to fix this?
>
> I've never noticed this with my work with the UHD. There are various
> commands issued to the USRPs to turn it on and shut it off between bursts.
> Maybe there's something missing in the gr-uhd.
> On the other hand, Josh and Nick have been working on using tags with gr-uhd
> on the transmit side, which should fix your problem.
> Any comments from the UHD folks?

Brett, if you are using anything beside the BasicTX or LFTX, then it's
also possible you are seeing LO feedthrough/DC offset in the transit
mixer, which results in a carrier output between packets.

Johnathan