I am restoring a Zenith AM-FM table radio that uses a selenium stack as a half-wave rectifier it has no power transformer). I would like to replace the selenium diode with a modern silicon diode. My question is - what was the voltage drop across the selenium diode (when it was new). I figure I'll need to add a dropping resistor in series with the (replacement) silicon diode in order to get the design voltages to the tubes. Otherwise, the tubes will see higher (possibly excessive/damaging) voltages. A search (selenium) of this forum did not turn up anything. Surely others have run into this same problem, as these devices were used extensively in the 40s and 50s.

TIA,

Bob