GPS Receiver Daughter-boards / Antennas

GNU Radio
1

Hello,
I am trying to implement a GPS receiver in GNURadio. I am wondering if
anyone has suggestions on which daughter board I should be using for
the receiver. I currently have a DBSRX-LF board and also a RFX1800
board that both seem to operate over the correct frequencies but am
wondering if there is a reason I should prefer one over the other.
(ex. Noise performance, Antenna Interface…) I am also open to
suggestions if there is another board that I should be looking at
instead.

Also, I am wondering if there are any suggestions on the antenna that
I should purchase. It is my understanding that I will need an active
antenna and am wondering how I should interface it to the board.

From past messages I gather that I will need to provide a DC bias and
there are at least three ways to do this. What are the benefits of
using an off-board tee instead of what is included on the board? I’ve
seen some antennas that come with there own power supply and thought
that this may take care of this problem?

Thanks for any help/suggestions.

Bryan

2

Bryan:

The DBS-RX is the way to go. I use the +5V bias on the DBS-RX, and it
works fine, with the added benefit of not adding another AC-DC brick to
your setup. To enable the +5V bias just short J101 on the DBS-RX card.
Checkout www.gps-sdr.com, you might be interested.

3

Does anyone know of a GPS antenna that they have had good experiences
with and would recommend?

Thanks

Quoting Gregory W Heckler [email protected]:

4

After reading a bunch of questions about GPS antennas I am making myself
the guinea pig. I just ordered the “Mighty Mouse 3” active GPS antenna.
The spec sheet quotes +5dBi gain at zenith and -1dBi at 10 degrees. I
ordered the antenna from:

http://www.gpszone.ca/accessories/antennas/mm3.php

The spec sheet is available from the manufacturer at:

http://www.tri-m.com/products/systems/mm.html

I will post a review once I receive it and give it a spin on my USRP.

–
[email protected]
NASA Goddard Space Flight Center
AETD - Mission Engineering and Systems Analysis
Component and Hardware Systems Branch
Mail Code 596, Greenbelt Rd.
Greenbelt, MD 20771
(301) 286-6565
(301) 286-3823 (fax)

5

On Mon, Jun 23, 2008 at 04:59:20PM -0500, Heckler, Gregory W.
(GSFC-596.0) wrote:

I ordered the “Mighty Mouse 3” active GPS antenna…

My evaluation of the antenna (in Ebayish): A++++ .

Thanks for the report!

Eric

6

GPS Geeks:

I ordered the “Mighty Mouse 3” active GPS antenna. The spec sheet quotes
+5dBi gain at zenith and -1dBi at 10 degrees. I ordered the antenna
from:

http://www.gpszone.ca/accessories/antennas/mm3.php

The spec sheet is available from the manufacturer at:

http://www.tri-m.com/products/systems/mm.html

I purchased an AC/DC inverter for my car and connected the USRP, a
laptop, and the Mighty Mouse 3 antenna and went cruisin’.

My evaluation of the antenna (in Ebayish): A++++ . It works great, was
cheap, and works “out of the box” with the USRP. It has a magnet built
in the base so you can throw it on your car roof without a worry. If you
order it, just be sure to indicate that you require an SMA connector
(the type provided with the USRP). When you connect it to the
USRP/DBS-RX be sure to bias the line by shorting jumper 101 on the
DBS-RX.