Re: [Discuss-gnuradio] Help: about ./benchmark_rx.py

[Mattias Kjellsson]

> > Sorry, but your question is not very clear. It's a wireless modem, which
> > means it's subject to all sorts of issues that are dependent on your
> > setup and parameters.
> >
> > The best thing to do is to start simple and use usrp_fft.py to see if
> > you can observe any signal at the receiver and that the signal has a
> > good SNR. If you have the qtgui package installed with GNU Radio, you
> > can also try to use benchmark_qt_rx.py which will show you the received
> > signal and the baseband symbols (so you can look at the constellation).
> >
> > Tom
>
> Dear Tom
> I can observe signal when I use usrp_fft.py.
> But, How to know the SNR is good SNR?
> When I use TVRX the signal very was clear, but the BasicTX was not.
>
> In fact, I can use two RFX900 daughterborads to do the
> ./benchmark_tx.py -f 900M and ./benchmark_rx.py -f 900M.
> I think that's becasue they have same frequency range (750 to 1050 MHz).
> But, if I use the BasicTX and TVRX to do ./benchmark_tx.py -f 100M and
> ./benchmark_rx.py -f 100M, I can't run if.
> Because they have different freqency range?
> TVRX daughterborad is 50 MHz to 860 MHz Receiver
> BasicTX daughterborad is 1 MHz to 250 MHz Transmitter
>
> Or because antenna ?
> I buy the BasicTX, but not include antenna, so I use RFS900's antenna
> instead it.
> The result was TVRX can receive FM channel, But BasicTX can't send
> signal..
Hi,
It might not be related but, when reading from
http://www.ettus.com/faq#norf I found:
Q: With the BasicTX can I transmit basic FM and AM, without additional
hardware?
A: Yes, the BasicTX will put out about 1mW up to about 50 MHz. A simple
connectorized amplifier (ala MiniCircuits) will get you greater range.
You may also want to add some low-pass filtering.

Regards
/Mattias
> > > Hi:
> > >
> > > I want to try my daughterborad basic_TX and TV_RX.
> > > I try to use ./benchmark_tx.py -f 100M and ./benchmark_rx.py -f 100M
> > > Only the ./benchmark_tx.py can run, The ./benchmark_rx.py can't
> > > receive any signal.
> > > So, what's wrong about this? How can I do?
> > >
> > > Thanks in advance.
> > >
> > >
> > > *Mei-Wen Li (Emily)