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<img style="max-width:100%;height:auto;" src="https://scontent.xx.fbcdn.net/v/t1.0-9/26907211_10156100234625127_5847315157477099673_n.jpg?oh=97f1e3383fed1b3b522cfe5edab76f81&oe=5AF5B61E"><br><br>And in what way is this "convenient"? Rewiring the radio? Hah?
"Here is an ad from Arcturus in the October 1927 issue of QST touting their AC radio tubes. No types are specified, but these are not the conventional GE/RCA AC types, since Arcturus claims "Four Prongs - Fits Present Sockets - For all D.C. Sets". Stokes, in his 70 Years of Radio Tubes and Valves has a good write-up on the Arcturus AC tubes (pp 167-169). These tubes used a 15V, 0.35A heater consisting of a carbon rod. The cathode was connected to one of the filament pins. So, these were not a "drop-in" replacement for battery types, but required some re-wiring and a 15V AC source. Sonora was one of the few radio companies to use these unique AC tubes. Arcturus originally only produced these, not making regular (i.e. RCA types) until after a reorganization in 1929. All of their tubes up to about 1934 used the signature blue glass bulbs."<br>(Posted on 2018-01-18 04:59:14 by <b>Metasonix</b>)
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