Just picked up a 1930s Battery operated Coronado

[vortalexfan]

OK, So I have a question about this radio:

Is it normal for a tube powered battery radio like this to drain the "B" Battery supply so that it goes from supplying 90VDC to the radio's B+ Circuit to a little over 50VDC to the B+ Circuit in the radio (which makes the radio barely operable) in less than 2 months?

I thought the "B" Battery supply was supposed to last almost two years with barely any use, and I'm using store brand 9V batteries like what was suggested by Radiotvphononut on one of his Youtube videos where repaired a similar radio to this and created a rigged up battery supply using modern 9V and "D" Cell Batteries.

Any Ideas as to what might cause this weird aforementioned issue?