The link buttons are just below the solar data.
The "R" letter was used by a number of stations in Canada in second, third, or fourth digit of the call
You do not mention the frequency of KBT, it should be on that list, unless it was a class "C" station operating limited hours, or assigned one of the frequencies marked on the list "Stations variously located".
It is very probable too that the station call letters were added in the fifties, their usage was not limited to the thirties only.
: I am looking for any information related to three stations listed on my 1935 Detrola Dial. I
: have searched the WEB for these stations and I am about to give up on Detrola's accuracy.
: Station KBT (not KBTM or WKBT); Station WMOK (not the Metropolis IL station whish is not
: that old or the Indiana station of 1950-51); and what I believe is a mistaken call Station
: CRCW because I don't think Canada used an "R" though I have seen it on other Detrola sets.