Found the below (
https://www.radioenthusiast.co.uk/articles/milli-hertzing-with-carrier-sleuth ) via an email from "Radio Enthusiast"; publishers of Practical Wireless & Radio User magazines in the UK.
‘Milli-Hertzing’ with Carrier-Sleuth - Optimise your Medium Wave DXing
A Brilliant New Piece of Software
‘Millihertzing’ seems to become “le must” of this season. The most recent software stems from smart software author Chris Smolinski, W3HFU, who over many years offers inspiring software. His new offering is dubbed Carrier Sleuth. It analyses I/Q-WAV files from software-defined radios at high resolution. It is thus the perfect tool for measuring offset frequencies on medium wave. The screenshot on this page top shows such a spectrogram, covering 20Hz in width - and 24h in length - on 590kHz.
Why would you use Carrier Sleuth, when you can have SDRC V3 to hand? First, the program works with a multitude of WAV formats from many different varieties of SDR software (Chris’ list, which is still expanding). Second, it lets you ‘hop’ from one channel (9kHz or 10kHz) to the next – if a proper part of the spectrum has already been converted from WAV to FFT.
The software can also convert spectrograms to CSV to apply some statistics on each signal. There are many more smart features, and Chris will more soon, for example for the processing of I/Q files in real-time to save a lot of time.
My bread-and-butter SDR software is SDRC V3, and I record in WAV RF64 one-file format (which sometimes swells to nearly 10TB). Carrier Sleuth can even digest these recordings with a workaround: specify an interesting part of the medium wave, defined by upper and lower channel and time segment, and convert this into simple WAV. This is easily done with SDRC V3’s Data File Editor. It is also the way Carrier Sleuth produced the screenshot on this page.
Chris published this software first on 10th December 2020. He eagerly looks for bug reports, applications and further suggestions form the users. Take a free test drive. The full registration code costs US$ 19.99.
The other image on this page shows a timeframe of 24 hours on 590kHz, on 19th January 2021, in Northern Germany. This reveals a couple of North American signals with VOCM of St. John’s, Newfoundland the strongest and KQNT Spokane on 590.002kHz/Washington State the most interesting, also enabling reception in the afternoon.
Watch out for an extended news item on Carrier Sleuth in the March 2021 issue of RadioUser.
(Courtesy, and with thanks to RadioUser contributor Nils Schiffhauer)
https://dk8ok.org