BBC 198 kHz temporary power reduction in February 2023

Pieter-Tjerk de Boer, PA3FWM pa3fwm@amsat.org

Below is a plot of the signal strength of the BBC's 198 kHz signal as received in Enschede, the Netherlands in February/March 2023. Vertical axis is relative power in dB; carrier power has been averaged over 1-minute intervals and plotted as dots. Horizontal axis is UTC date.

We can see the signal level dropping some 2 to 3 dB weaker on February 23, and returning to its previous level on March 2. (Note that the received signal strength is quite variable due to propagation effects, but in the middle of the day the propagation is stable enough to see this.)

Although one could speculate this was an (unannounced) test to see how much impact a power reduction (and associated energy cost savings) would have for the listeners, it wasn't. BBC Audience Services says:

Regarding transmission from Droitwich, a fault occurred at 18:41 on the 22nd of February and service was restored to full power at 16:38 on the 1st of March. Further checks were undertaken on the 2nd of February between 14:16 and 15:18 requiring the service to be in reduced power to confirm the issue had been fully resolved.

Indeed, the March 2 check can be seen if we zoom in on the data: It seems a similar check was done in the morning, though one never knows if it's not simply a propagation effect.

(This power reduction was brought to my attention via the fr.rec.radio newsgroup.)