Dumont RA-109 tubes question

[kramden66]

ah ha riders tv trouble cures vol 1 says to improve sensitivity replace the first and second if 6au6 tubes with 6bc5 tubes , there are other changes but they were not done to this set , so apparently it will function with those two tubes , the other mod is replace 4th if with a 6bc5 and remove the ground connection from pin 2 of the 4th if , the 6au6 is still the 4th in this set , also replace the last if transformer with a different one , so either dumont or someone else decided to put the two 6bc5 tubes in and that was good enough.

mike