[AMRadio] 4-400 first made when?

Craig C. Heaton wd8kdg at worldnet.att.net
Fri Mar 23 21:19:35 EST 2007

To All,

Looking at an old 1958 ARRL handbook, the 4-400A is listed in the tube data
pages. Can't go back further. This is the oldest in the library, besides I
was but a mere lad at that date.


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