An Innovative Use of a Great New Receiver 

Preparations are in full swing here at RadioUser, for the big review of the new ELAD FDM S-3 Software-Defined Radio in one of our next issues.

In the meantime, our good friend and RadioUser contributor Nils Schiffhauer has found an excellent new way of making the best of the facilities offered by this amazing new receiver. Here is an excerpt from his website:

With the new Elad FDM-S3 and its OCXO/GNSS-stabilized clock, I did a 24h recording of the whole medium wave band on 19^th January  2021, in Northern Germany.

The free software SDRC V3 enabled me to make up a spectrogram of each channel within a window of 50Hz width and at a frequency raster of 10kHz. You can easily see:

• sign-on/sign-off
• fade-in/fade-out
• accurate and stable frequency offset over full 24h down to a millihertz
• frequency control of the transmitter’s oscillator (stable, drift, sinus, sawtooth …)
• propagational effects (doppler, scatter …)

The format is PDF, DIN-A4, landscape, resolution 300dpi – see screenshot at the bottom. This allows you to zoom to a factor of about 400% to search for details and a better readout of the time/frequency scale.

The data amount to 559MB. You can download it here and open it with your PDF reader (you can also point your mouse cursor onto the link, right-click and choose 'Save under …'.

Leafing from one page to another will offer you an interesting overview.

Yes, a similar Atlas showing a raster of 9kHz is underway and will be published in due time. It is also planned to publish a general article about the background, about what to do with such a tool, and how to do this by yourself.

I am sure that it will open some new horizons on Medium Wave DXing, including accurate offsets over up to 24h.

The ELAD FDM S-3 is available in the UK from Martin Lynch and Sons Ltd.

https://www.hamradio.co.uk

Nils Schiffhauer – DK8OK:

https://dk8ok.org/2021/01/31/medium-wave-offset-atlas-all-10-khz-channels-24-hours