bought a Marconi Adret 4101A 15-200 kHz frequency standard receiver at a ham rally.
Essentially an OCXO dsciplined against a VLF time standard transmitter. Had to clean out the old NiCd batteries that had long ago dumped their electrolyte on the mainboard but for the rest it is very clean for a 1990 unit. I am using it with DCF77 at 77.5 kHz for now, as it came with a nice Meinberg DCF77 outdoor antenna,
*** Please PM me if you happen to have docs on this model, sofar I only found a spec sheet by Adret.
Wilko