RCA 6181 does not compute. I could not find it in my databooks. The 6166
does, but that's a tetrode rated for TV application, 10 KW dissipation,
about 11 inches long, 6 inches diameter, 15 lbs. The 6161 is a 900 MHz
triode that is 3 inches long, 1.7 inches diameter. Nothing listed in
between, in my old books.
The pink ceramic was made by Frenchtown. They are no longer making it. RCA
(now Burle) now uses white ceramic. And many of the old Cermelox tubes are
no longer made.
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