Category: Volume 16

A late-“20s RCA promo – a minstrel version of the “Radiotron Man” (see TC cover, Feb. 2009). This is from some dealer sales-support material discovered by Joe Knight.   In this issue

A family of early-’20s Magnavox triodes, as covered, along with the newly revealed “Kathion” rectifier, in the lead article.   In this issue

Well known colllecytor Udo Radtke with a Brown Boveri BTW150-2 power triode. The little package carries a dissapation rating of 220kW. Technical data and more photos are available at http://www.tubecollection.de/types/BTW150-2.htm. Note the spiral oxidation pattern on the anode, presumably the result of a cooler designed to give a helical flow of the cooling water.  ...

Inside a Western Electric ES-9709B oak-cabinet repeater “gain Element” of the type used at Brushton outside Pittsburgh on the 1914 transcontinental line. (For a front view, see inside this issue, or p. 93 of Tyne’s Saga of the Vacuum Tube.) The pair of Everready multicell dry batteries labeled “C Battery” may reflect the first commercial...

Two versions of the Eital-McCullough 4W20,000A power tetrode: at left., an early version (1952), cut open to reveal the “bombardment” cathode; at right, one from 1955. This tube is documented extensively in TC for oct. 2010. A very early bulbedd model, possibly the X486 protype, is illustrated on Norm Wilson’s n6jv.com web site.   In...

A group of Eitel-McCullough stacked-ceramic receiving tubes from the “CD” project of the mid-50’s. Details in the article inside.   In this issue