(!!) (Best Single) UY-227 RCA Radiotron Balloon tests like new 1930 era (10.2ma)
(!!) UY-227 RCA Balloon NOS 1930 era (4.3ma)
(!!) UY-227 RCA Radiotron Balloon used/good 1930 era (3.5ma)
(!!) UY-227 RCA Radiotron Balloon used/good 1930 era (3.7ma)
(!!) UY-227 RCA Radiotron Balloon used/good 1930 era (3.8ma)
(!!) UY-227 RCA Radiotron Balloon used/good 1930 era (4.0ma)