I have two clips of audio I received at my station this AM around about 1430Z on 40 meters CW. Since I have been talking about noise and how it affects receive I thought I would show you what it sounds like. I didn’t do much prep or tweaking of signals selected. Ill try to get some more tomorrow as I thought about this as my western enhancement was going away well after my sunrise here.
A few condition reports to set things up. We are in the middle of local thunderstorms in my area. Not so close as to shut me down but close enough to hear. The antenna is a 50 foot long dipole up about 27 feet fed with homemade balanced feed line and a Palstar BT-1500A tuner. The receiver is a IC-7800 with the filter mods installed. In all cases recorded I was using 3KHz roofing filter set to sharp response curves with normal 250 Hz CW B/W CW filtering selected and APF broad (320 Hz) set to “On”. In my case all four transmit common mode chokes are in line in the feed line. In general I had the receiver “screwed down” pretty tightly today. Later I will look for a more diverse set of recordings. Varying B/W’s and with/without APF etc. etc. Recording length is limited to 15 seconds due to my using the Icom internal recorder. I think there is a way to concatenate 15 second segments together but I haven’t used that feature so that may require the manual.
First recording is from JA7DLE
Now from CF3XOV
I will try to find some more audio clips to upload. The SNR is what is important here. In spite of received QRN levels from the thunderstorm and many loud signals present I found gaping open spots in the band this morning. Amazing considering the amount of loud stations present. I would like to output the spectrum display in unison with the audio clips so one could better visualize the SNR and see activity levels. I haven’t found an inexpensive solution to capturing both vga video and mp3 audio yet but time should provide a solution.
Thanks for reading. Best, Chas W7MAP/5