Re: [Discuss-gnuradio] help with "safe" and "clean" band

[Martin Dvh]

Mihail L. Sichitiu wrote:
> Hi there,
> 
> I'm brand new at this GNU Radio thing, so please forgive me if my question
> has a "well-known" answer. I'd like to try out some performance tests on a
> few modulation schemes, so I need a clean band for these tests. Obviously
> the 2.4GHz ISM band is full of interference, and I assume that this goes
> for all the other ISM bands, right?
> 
> If this is the case, is there a well-known relatively quiet band where I
> can run these tests without interfering with anything important, without
> being interfered with, and without getting in trouble with FCC?
The easiest thing to do would be not doing your tests wireless.
Connect TX twith coax to  an attenuator and connect that to the RX side with 
coax.
That is about as clean as you can get, and you won't interfere with anyone on 
any band.

Make sure you use enough attenuation. The RFX2400 TX side has much more power 
at its output then the RX side can handle.
You will blow up your daughterboards if you don't have at least 30 dB 
attenuation.

The best attenuators I found for high frequencies are the SMA inline types
You can mount them directly at the TX output and connect a SMA-SMA coax to the 
RX side of a second RFX2400.

Things are much more relaxed with basicRX and basicTX.
basicRX can be connected directly to basicTX without any chance of damage.

I do a lot of my testing with basicRX and basicTX.
The output of basicTX is also very low which is an advantage in this case.

Greetings,
Martin


> 
> I imagine that if I'd have all the daughter boards I could do a long-term
> (1-2 days) scan and find a quiet band and play in there (the tests are
> likely short and low powered). The problem is that I only have the 2.4GHz
> daughter-boards and I'd like to buy only the "right" daughter-boards (as
> opposed to all of them to find an empty band).
> 
> Thanks for the help,
> Mihai
> 
> 
> 
> 
> _______________________________________________
> Discuss-gnuradio mailing list
> address@hidden
> http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>