Re: [Discuss-gnuradio] Fw: Need Advice for SDR choice

[Andrew Rich]

Very helpful thank you 


Sent from my iPhone
Andrew Rich

On 04/01/2011, at 5:22, "Mark J. Blair" <address@hidden> wrote:

> 
> On Jan 2, 2011, at 1:31 PM, Andrew Rich wrote:
>> I have a MacBook PRO I7 it can run OS X or windows
> 
> I have been successfully using the Ettus Research USRP with LFRX, LFTX and 
> WBX boards on my 17" MacBook Pro under OS X (Snow Leopard). Installing the 
> software portion is pretty easy: Install the MacPorts package, then run "sudo 
> port install gnuradio" in a terminal window. You can play with the gnuradio 
> software to see if it's right for you before committing to buying any 
> hardware, since it can use the audio device and/or data files as a 
> source/sink, or even run entirely simulated flowgraphs.
> 
> I haven't used any gnuradio-based canned ham radio USB/LSB/whatever 
> applications (if any exist). I have successfully received 2m FM transmissions 
> with one of the examples that comes with the gnuradio distribution. I've 
> mostly used my hardware to generate fairly simple test signals for other 
> radio hardware (i.e., a number of simultaneous CW tones within a fairly 
> narrow bandwidth) and simple spectrum analysis. At the moment, I'm playing 
> around with writing blocks and flowgraphs for sending and receiving 
> high-speed Morse code, due to my current interest in devices such as the 
> AN/GRA-71 code burst keyer (*). This is all pretty simple stuff that the USRP 
> hardware is overkill for, but I'm just beginning to learn about gnuradio and 
> SDR design in general.
> 
> Based on what you've stated so far, I think that a USB-based USRP with a WBX 
> board and the gnuradio software should work nicely for you, and you can work 
> with it directly under OS X. You may also want to get an RFX2400 board to hit 
> the 2.4GHz band (I have one, but haven't done much with it yet). This board 
> combination will leave a hole between 2.2GHz and 2.3GHz.
> 
> If I recall correctly, I've generally set my hardware decimation to limit 
> sampled bandwidth to about 2 MHz in order to avoid USB over-runs and/or 
> under-runs. I've been able to look at a 4 MHz bandwidth with occasional 
> over/under-runs. The occasional over/under-run doesn't seem to cause problems 
> when just visually watching an FFT plot (i.e., to look for activity within a 
> band).
> 
> I don't know if the Ethernet-based USRP platforms work on Macs yet.
> 
> 
> 
> 
> (*) More info here if you're curious:
> 
>    http://www.militaryradio.com/spyradio/gra71.html
> 
> These are available (though rare) on the surplus market, but I'm unaware of 
> any of the original receiving equipment that has made it out to the hands of 
> collectors. A SDR setup seems like a natural way to handle receiving the code 
> burst and then either playing it back at low speed for manual decoding, or 
> automatically decoding the transmission at normal speed.
> 
> -- 
> Mark J. Blair, NF6X <address@hidden>
> Web page: http://www.nf6x.net/
> GnuPG public key available from my web page.
> 
> 
> 
> 
> 
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