Artifacts from the USRP Digitizer

GNU Radio
1

To anyone using the following:

I’m using the USRP with a Microtune UHF band tuner.

What I see is that there is a significant artifact at 512 MHz, and a few
more, but
another ‘clear’ artifact at 640 Mhz.

I believe these to be induced by the digitzing clock of 64 MHz.

However, since I avoid ‘hardware’ like the plague, if others have better
explainations
and corrections I’d like to hear about them.

In terms of shielding, the Microtune module does seem to have shielding,
however, on
the USRP board, I do not see much leading into the Analog Devices chips.

We are looking at very low signal levels, and so perhaps others have not
seen these
artifacts, as they may be looking at much higher signal levels…

Thanks
John C…

2

John C. wrote:

However, since I avoid ‘hardware’ like the plague, if others have

Thanks
John C…

I see artifacts at multiples of 20Mhz. Somewhat unfortunate, since my
primary observing band is 1416-1424Mhz.
The 64Mhz artifacts fall outside my passband.