Looks good to me Ian 👍
Like an ADF searching for a navigation beacon.
DG is correct, it wouldn't continuously rotate on a civilian ship using RDF for navigation purposes. I.e. looking for a specific NDB (Non Directional Beacon).
On a warship in the old days it might rotate if the set was being used as a Search receiver.
Nowadays the antenna for such purposes does not rotate. Instead a fixed multi-element antenna is used and the detector receiver plots the progress of the RF wavefronts across the elements. Thus deducing where the signal came from.
So I reckon your setup looks pretty convincing for an older model DF set
Cheers, Doug 😎