[ABV]

Use the schematic for Model 84. Although, the only difference between a model 84 (also 37-84 Code 121) and model 37-84 Code 122 are the tubes used. The 37-84 Code 122 uses octals, while the older 84 used the equivalent standard base tubes.

77 = 6J7G
42 = 6F6G
80 = 5Y4G

And please note when I use the equal sign, I mean electrically identical. Of course the bases are different.

Only recently did I become aware of a 37-84 "Code 121," and I see I need to make some changes in my site's Gallery as a result.

Ron
A 84B type cabinet uses the old tubes 77,42,80 (code 121)  but I recently had two 84B type cabinets for epair using
chassis code 122 octal tubes. I checked your gallery and radiomusuem. It appears that 84B type cabinets used only
code 121 old tubes. Is that correct?
ABV