A problem about antenna

Hi,

I tried to use my gnuradio catch some radio signals in the air with
the script ./gnuradio-examples/python/usrp/usrp_wfm_rcv.py, but all we
heard is just some noise in FM frequency band(about 90MHz~110MHz), so
we guess maybe need an antenna to get a stronger radio signal.
our USRP has two daughter boards: basicTX and basicRX. And we mailed
to Matt E., here is letter and his reply (say sorry to Matt E.
for publishing this letter):

-----------from here-----------------

We’ve got 3 USRP packages ( also 3 basic RX-daughter boards and 3
basic TX-daughter boards). However, it comes without antenna in the
box. We want to know that if we are required to buy antenna from you
if we want to perform experiments between those USRP devices? If yes,
which mode is suitable for us? Thank you.

Antennas are not included in the purchase. You will need to get your
own. We do not sell antennas which match the frequency range fo the
basic rx and basic tx, so you will need to purchase those elsewhere.

Thanks,
Matt E.
----------to here-------------------------

We’ve checked the interface of USRP, its SMA Female, and nearly all
the antenna’s interface for wireless which are sold in Fry’s
Electronics is SMA Reverse Plug. So I guess a adapter from SMA Male to
SMA Reverse Jack will connector the USRP’s RF end to an antenna.
Is anyone has any idea of the antenna, or where we could get such
adapter or some
link of website where we could buy antenna suitable for BasixRx/Tx
daughter board?

Thank all for any help,

Dong

On 7/19/07, Dong Li [email protected] wrote:

We’ve checked the interface of USRP, its SMA Female, and nearly all
the antenna’s interface for wireless which are sold in Fry’s
Electronics is SMA Reverse Plug. So I guess a adapter from SMA Male to
SMA Reverse Jack will connector the USRP’s RF end to an antenna.
Is anyone has any idea of the antenna, or where we could get such
adapter or some
link of website where we could buy antenna suitable for BasixRx/Tx
daughter board?

SMA Adapters:
SMA Adapters

That should provide most any connector you might want to throw at the
thing.

I might as well take the time to add that if you want to cable
directly between USRPs you should use an attenuator, and it might be
worth while to get some kind of combining circuit if you wanted to do
spectrum analysis as well.

Most of the attenuators and combiners I’ve used come from here:
fxr.com

I have to admit I don’t know their pricing, but they are very high
quality from my experience.

Brian

Dong Li-

:
:
We’ve checked the interface of USRP, its SMA Female, and nearly all
the antenna’s interface for wireless which are sold in Fry’s
Electronics is SMA Reverse Plug. So I guess a adapter from SMA Male to
SMA Reverse Jack will connector the USRP’s RF end to an antenna.
Is anyone has any idea of the antenna, or where we could get such
adapter or some
link of website where we could buy antenna suitable for BasixRx/Tx
daughter board?

You can replace the connector on the RF daughtercard with SMA male
connector. It’s
thru-hole, easy to unsolder and replace.

-Jeff