Re: [Discuss-gnuradio] Differences in Signal Spectra between Daughtercards

[Thomas]

I thought the same thing when I first saw it, but reducing the gain doesn't make a difference. At the link below is a screenshot of the result of lowering the TVRX's gain from 30 to 10. The gain is low enough that what I assume is a DC-offset from the ADC can be seen in the center of the plot.

http://img687.imageshack.us/img687/6281/screenshotusrpfft4.png

Thomas

--- On Mon, 1/11/10, Johnathan Corgan wrote:

From: Johnathan Corgan
Subject: Re: [Discuss-gnuradio] Differences in Signal Spectra between Daughtercards

On Mon, Jan 11, 2010 at 08:58, Thomas wrote:

> I'm curious why the spectra of signals received with the TVRX seem to be more spread out than with the DBSRX. An example is shown in the link below. The upper plot is from the TVRX, and the lower plot is from the DBSRX. This signal happens to be an ATSC carrier. Both daughtercards are tuned the same frequency, and the FFT parameters and so forth are identical.

It looks like the gain on the TVRX board is set too high.

Johnathan