[MrFixr55]

Hi Mike,

Yeah, use 45V when using either 201 or 201A as a grid leak detector.  Same with WD11s, 30s, 199s, 27s, etc.  The only tube that uses 22.5V when used as a detector that I know of is the 00 (UX200) and the rare 200A. 

Therefore, I don't know why ARBE shows 22V for all those sets when they state that the connections are for sets where all tubes are 201s.  Both the 00 and 00A became unpopular by 1930 or so; pages for the 00 and 00A were dropped from the RCA Receiving Tube manual Version RC-10 published in 1932, while the 01A (UX201A) still received a full page.  I don't know when they stopped making 00As, I have never seen an ST version.