KFS omni kiwi sdr "Masking" USAF global HF Frequency??

[ZL/KF6VO]

Pardon the stupid question but before you excluded the masked areas form the SNR calculation, were they showing as SNR = 0 dB (which is my first thought) or are they showing as SNR = "huge dB", because the signal level is still available to the SNR calculation (despite the mask) and the noise in the masked area is basically zero?

Apologies for the late reply. I don't read here very often.

The answer to your question is "it depends". The SNR ranking algorithm takes a sample of all the waterfall bins (in dB), sorts them, uses the value of the 50% bin (median) as the "noise" level, and the 95% bin as the "signal" level. The difference (95% value - 50% value) is taken as the SNR. Prior to eliminating the masked bins this means that if there were enough of them to effect the 50% noise level value (after sorting) the SNR would become huge (noise level = -200 dB or something).

[rnewell@shaw.ca]

Tried tuning in 11,175 KHz yesterday and I could see activity on the waterfall but no audio. Then I noticed this tag


So what sort of feature is this on the SDR and what is it normally used for? It was not applied to other global HF frequencies.

Thanks!

OK - I see the discussion about MASKING certain frequencies -- I have issues with listeners camping on AERO frequencies al day --

HOW do I mask out frequencies to stop these pests?

[RobRich]

I hope ya' got it working by now, rnewell. However if not, go to the admin DX tab, create another entry, set the frequency, mode (USB), and type (masked).


HFGCS campers have descended on both my Kiwi and my Web-888 receivers.

Recently I have had like the same few people (well, IPs) camp on HFGCS frequencies for multitudes of hours. I skipped checking the SDRs for a couple of days earlier this week, but once I did get around to it, I noted one person was logged into my Kiwi for over 30 hours in just one session apparently monitoring 11175. o.0

i am opting for masking at the moment. I would hate to set time limits. Sigh.