Re: [Discuss-gnuradio] GPS active antenna biasing

[Matt Ettus]

Gregory W Heckler wrote:
> You can do this externally by putting in a bias-tee in the RF line
> prior to input to the USRP. I've personally used the following from
> MiniCircuits:
>
> http://minicircuits.com/pdfs/ZFBT-4R2G-FT.pdf
>
> Or if you want to take a more risky route, on the DBSRX daughterboard
> there is header to input a DC voltage. I'm trying to do the same thing
> (GPS with the DBSRX & USRP), and am not going to risk frying something
> at this point. Hope this helps.
>

There are 2 ways to use the built-in bias tee on the DBSRX --

1 - If you want to supply your own voltage, apply it to J100.  Put + and
GND on the marked pins

2 - If you want to use the onboard 5V regulated supply, DON'T connect to
J100.  Instead, place a short across the pins of J101.  The board is
unfortunately labeled "6V", but it is actually a regulated 5V.

Matt