The ATR1-A transmitter was made for the Canadian aviation market.
Modes: CW/MCW/ Phone
CW - 35 or 40 watts
MCW - 15 watts
Phone - 10 watts
Ciirca: Jamuary 1938
All that's available right now is the ATR1 sales brochure which can be viewed here.
Contributors and Credits:
1) ATR1-A sales brochure found on E-bay