[Hackrf-dev] FM transmitter

[Wang Kang]

1.

50 nW = -43.0103 dBm

You can easily put your tx level below this energy by adjusting three gain 
controller of HackRF.

In fact, the maximum output level of HackRF One in FM Band is around 10 
dBm (with RF Tx amp on). The RF Tx amp is 13 dB gain.

2. According to my experience, RF Tx amp can be easily damaged (perhaps the 
VSWR of antenna port is too high). So you shouldn't do Tx while antenna 
port is open.

On Thu, 20 Aug 2015, Sukandar Kartadinata wrote:

> Hi,
> having worked my way thru the first few tutorials/videos and gotten the FM receiver working, I would now like to try my first “hello world” in the opposite direction, i.e. transmit an FM signal. I’m sure I should be able to find something on the GNU Radio wiki to cobble that together, however I’d like to ask on this list about any HackRF specific details I should pay attention to.
>
> For one thing I’m aware that transmitting in the typical FM bands is only allowed if you keep the energy low enough. In Germany, where I am, this is listed as 50nW maximum. How would I make sure that the HackRF transmits within this limit?
>
> I also want to make 100% sure that I don’t damage the hardware. Is it sufficient to keep the RF Tx amp disabled or do I need to configure something else?
> [...]