I should have mentioned that the K4 also has a panadapter noise blanker that's very effective. It removes pulse noise that would otherwise cause the panadapter noise floor to rise, where it might obscure weak signals.
The display NB can be turned on automatically at the same time that the receiver blanker is turned on (AUTO setting), or turned on/off manually. Either way, the level settings for the display and receiver blankers are independent and per-band. While recording the noise sample I just provided, I had the display NB on as well. It knocked the noise level on the panadapter down by about 20 dB. Weak signals could be clearly seen. 73, Wayne N6KR > > On Mon, Feb 22, 2021 at 2:15 PM Wayne Burdick <n...@elecraft.com> wrote: > A brief K4 audio sample can be downloaded using the link at the end of this > email. > > This recording hows how the new K4 noise blanker algorithm can reveal a > signal buried under loud noise. It also highlights the effectiveness of the > audio-peaking filter (APF) when listening to a very weak CW signal. > > This was recorded on 17 meters, CW mode, in a 1 kHz bandwidth. Both receivers > are turned on, tuned to the same frequency, and the recording is stereo. > There's a slight delay between main and sub RX audio as the settings change; > this is due to tapping A>B to copy the main RX NB and APF settings to the sub > RX. > > Things to listen for (T in seconds): > > T0: S-9 noise masking very weak carrier > > T7: Noise blanker turned on so that only atmospheric noise remains; > carrier now barely audible > > T14: APF turned on, 30 Hz BW; carrier clearly audible > > T23: Carrier disappears, leaving band noise only > > http://ftp.elecraft.com/K4/K4_audio_samples/K4%20NB%20demo%201.mp3 > > 73, > Wayne > N6KR ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
