Noise Floor

Hi Richard, noise floor depends on the bandwith of the reciever you can see more with details regarding F6000 on: http://community.flexradio.com/flexradio/topics/band_gain_noise

Here is what Steve (N5AC) VP Engineering had to say about noise floor ......Both the panadapter and the meter in a slice receiver show the noise floor level when a signal is not present in a bin or passband, respectively. In the case of the panadapter, the bin size changes with zoom level and so the noise floor will consequently change. For example, if your pandapter is zoomed in to say 15kHz wide, your bin size is 5.86Hz per bin. If you zoom out to 30kHz, you are now looking at a bin size of 11.72Hz. Since there is twice the bandwidth, there will be twice the noise in the bin and the noise floor will rise by 3dB. On the other hand, the receiver noise bandwidth is set by the filter in the slice receiver. So if you set it for 500Hz, your noise level is much higher than is in the panadapter bin which is being measured at only 5.86Hz (almost 20dB difference). Another way to see this is to set your bandwidth in the slice receiver to 500Hz and then hover over the S-meter. Where I am, I get a noise floor reading of -121dBm on 20m. I then expand the filter to 2.5kHz and I read -114dBm. The calculated difference is 10*log(2500 / 500) = 6.99dB and of course -121dBm + 6.99dB = -114dBm. Then if I go down to 50Hz bandwidth in my receiver filter, I read -131dBm. The calculated value is 10*log(500/50) = 10dB better or -121 -10 = -131dBm. This is how noise measurement works and why you have to specify the bandwidth where you are measuring the noise. Finally, if you are connected to an antenna, your noise floor will change (of course) based on the antenna type, the noise level and type at your location, etc. Steve