Re: [Discuss-gnuradio] Problem with arguments in benchmark_tx and rx

[Tom Rondeau]

On Thu, Sep 1, 2011 at 4:39 PM, sumitstop
<address@hidden> wrote:
>
> I got a reply for this post by Nick Foster but its not showing here.Anyways I
> am posting It here
>
> Nick answered --- "So, first of all, you're using an attenuator, right? You
> can't transmit directly from one RFX2400 into another without the
> possibility of damaging the receiving RFX2400."
>
> --n
> *******************************************************************************
> Nick .... I connected them using SMA-SMA cables.Does this mean that I have
> damaged them already ?
> I thought these cables will provide the required attenuation.
>
> Anyways I have a general question..
> I have two basic Tx and Rx daughter boards.
> say I put the Transmitter daughter board on side A of USRP.Now the
> Transmitter daughter board has two ports TX-A and TX-B. What should I write
> for the arguments while running benchmark_tx.py
> Iis  the following correct ............
>
> Side A and TX-A ----> -T A:0
> Side A and TX-B ----> -T A:1
> Side B and TX-A ----> -T B:0
> Side B and TX-B ----> -T B:1

SMA cables have very little attenuation. Look at the table of cables
at http://en.wikipedia.org/wiki/Coaxial_cable. You can see that cables
are rated for a few dB of attenuation per 100 feet. You definitely
need real attenuators in line with your cables in your setup.

Tom