RFX2400 using 2.4-2.48GHz Patch antennas

Joseph Crowley wrote:

Just purchased a couple of RFX2400 transceiver dboards as well as a
couple of patch antennas (WA5JVB) and tried running the benchmark
program from one USRP to another (both mounted with the RFX boards).
However it didn’t seem to work. I tried looking for a spike using the
fft on the receiver USRP but found only a spike at 2.4GHz (from
surrounding wireless hardware) which didnt change during transmission
(using benchmark_tx.py). Was just wondering what the problem is if
anyone else has encountered it. i.e. is it a problem with the boards? Or
antenna? Or is it a problem with the benchmark script?

-Joseph Crowley

You’ll have to provide more information than that. Which benchmark
script and what were the parameters? What was the setup of the
experiment (TX-RX distance)? Have you successfully run other GNU Radio
applications? Try usrp_siggen and usrp_fft.


The commands being used are:

./benchmark_tx.py -f 2.4G -T A --tx-amplitude=10000 -s 1000 -r 1 -v -M 5

./benchmark_rx.py -f 2.4G -R A -r 1 -v

used rate of 1 just to set to lowest possible bitrate (for gmsk 35 kb/s)

Distance have ranged between 1 - 2 metres.

When using usrp_fft.py on the receiver the transmitter Rf power is
showing on the display (pretty large >10db gain from the noise floor).

Problem now is the receiver is not receiving any packets.

Joseph Crowley

Hash: SHA1

In my experience the USRP stops performing very well at low bitrates.
This is due to the current code’s inability to handle large frequency
offsets when the symbol period is that long.

Try it at 250kbps/500kbps.

  • -Dan

Joseph Crowley wrote:

Distance have ranged between 1 - 2 metres.

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