From 99ce29175d5a7883adbd63383a3e6fe33cabfcca Mon Sep 17 00:00:00 2001 From: Arturs Artamonovs Date: Fri, 22 Nov 2024 03:02:32 +0000 Subject: sdr: update the cw with images --- md/notes/sdr/gnu_radio_receive_cw.md | 38 ++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) (limited to 'md/notes') diff --git a/md/notes/sdr/gnu_radio_receive_cw.md b/md/notes/sdr/gnu_radio_receive_cw.md index dd32c39..2c69a98 100644 --- a/md/notes/sdr/gnu_radio_receive_cw.md +++ b/md/notes/sdr/gnu_radio_receive_cw.md @@ -3,3 +3,41 @@ keywords:sdr,airspy,gnuradio # +Lets listen to CW/morse on HAM bands + +## Frequencies + +The easiest frequencies where CW tranmissions can be spotted are on +HAM bands. There is option to search for military related ones but those +are dependent on schedule. + +| Bands, KHz Lower Limit| Upper Limit | +| --- | --- | +| 3500 | 3560 | +| 5258.5 | 5264.0 | +| 7000 | 7040 | +| 10100 | 10130 | +| 28000 | 28070 | + +## GNU radio blocks + +Here is the blocks that monitors the CW on few HAM bands + +![AirSpyHF](/img/sdr/airspyhf_cw_receiver_part1.png) + +![AirSpyHF](/img/sdr/airspyhf_cw_receiver_part2.png) + +This creates tunes to central frequency as channel0 and channel1 +is offset from central frequency. To catch few CW transmissions if there is any +and allowe to switch between 2 of those with slider. + +## Links + +https://en.wikipedia.org/wiki/Morse_code +https://rsgb.org/main/operating/band-plans/hf/ +https://rsgb.org/main/operating/band-plans/hf/3-5mhz/ +https://rsgb.org/main/operating/band-plans/hf/5mhz/ +https://rsgb.org/main/operating/band-plans/hf/7mhz/ +https://rsgb.org/main/operating/band-plans/hf/10mhz/ +https://rsgb.org/main/operating/band-plans/hf/28mhz/ + -- cgit v1.2.3