USRP 2 Daughter Cards


#1

I am trying to use the USRP 2 radio. I have been using the
rx_streaming_sample script to collect data.

If I use the rfx1800 daughtercard the results from the set_center_freq
command seem correct but the output

looks as if the receive channel is not connected (changing gain does not
affect output levels).

If I try the lfrx or dbs daughter cards the set_center_freq response
appears
incorrect.

The baseband frequency is 0 and the ddc frequency is the negative of the
commanded frequency.

Any suggestions?

==============================

Jim Graham

Black River Systems Company, Inc.

162 Genesee Street, Utica, NY 13502

   e-mail : removed_email_address@domain.invalid

   voice  : (315) 732-7385 x146

   fax :     (315) 732-5837

==============================


#2

On Thu, Feb 19, 2009 at 10:15:29AM -0500, jim graham wrote:

I am trying to use the USRP 2 radio. I have been using the
rx_streaming_sample script to collect data.

If I use the rfx1800 daughtercard the results from the set_center_freq
command seem correct but the output

looks as if the receive channel is not connected (changing gain does not
affect output levels).

What OS, version, distribution, architecture?
Which version of the GNU Radio code?

Are you feeding this with a signal generator? What’s your input
signal level? Which antenna port are you connected to? Have you tried
running usrp2_fft.py?

If I try the lfrx or dbs daughter cards the set_center_freq response
appears incorrect. The baseband frequency is 0 and the ddc frequency
is the negative of the commanded frequency.

Those values are correct. Have you tried injecting a signal into the
board and looking at it using usrp2_fft.py?

Eric


#3

On Thu, Feb 19, 2009 at 01:21:37PM -0500, jim graham wrote:

Eric

We are using Fedora Linux version 7 on an x86 machine.

OK.

[Please be sure to hit Reply-All to reply to the writer and the list.]

The GNU radio software is Revision 10211 (jcorgan)
Last change date 1/12/2009

We have the USRP 2 connected to a directional antenna. I have used the
dbs daughtercard hooked to the same antenna with a USRP 1 to verify
a signal is present.

For the dbs and lfrx daughtercards are the set_center_freq outputs of 0 for
Baseband freq and -commanded freq for ddc freq correct?
The output of the call using a flex1800 daughtercard is different.

What rx_daughterboard_id() does the USRP2 report for your RFX 1800?

With regard to RFX boards, the USRP2 only supports the MIMO_B version.
Any board that the firmware doesn’t recognize is treated as a Basic Rx
or Basic Tx.

Eric


#4

On Thu, Feb 19, 2009 at 02:52:41PM -0500, jim graham wrote:

Eric,

rx_daughterboard_id() returns id 0x0034 for the RFX 1800 daughtercard?

That’s a MIMO B board, so you should be fine.

For the comment on the RFX boards; does this mean we are unable to use the
dbs daughtercard on the USRP 2 unit?

No, the DBS RX is supported.

Eric


#5

Eric,

rx_daughterboard_id() returns id 0x0034 for the RFX 1800 daughtercard?

For the comment on the RFX boards; does this mean we are unable to use
the
dbs daughtercard on the USRP 2 unit?

– thanks
jim

==============================
Jim Graham
Black River Systems Company, Inc.
162 Genesee Street, Utica, NY 13502
e-mail : removed_email_address@domain.invalid
voice : (315) 732-7385 x146
fax : (315) 732-5837