Russian 4Aa Condenser ---1935 -42

No doubt this microphone is similiar in appearance (except
for its yoke) and working to that of the RCA-4Aa
microphone. It is also being called the 'Box Brownie' This
mic posses the inherent advantage frequency
characteristics as well as negligable background noise and
hiss. It is designed to convert electrical vibrations to sound
waves at a freq. of 30 to 10,000 cycles.

Graham McNamee was a great radio announcer. Legendary
for his sports casting of baseball, football and boxing.