[K6BW] Meeting Tonight at Hamilton

[Bill Smith]

Jack, WA6JYU and Bill, AB6MT are replicating the National SW-3 shortwave
receiver.  The SW-3 is a three-tube regen set National made between 1931 and
1940.   It is a three-tuber, made in various configurations for battery
and/or AC use, and was manufactured through its lifetime with at least three
different generations of tubes.  So far, we have identified at least 5
versions of the circuit.

It is a very basic receiver derived from National's original AGX series
regen receiver.  The AGX was designed for aviation and cost a small fortune,
$300 in 1931 depression dollars.  The AGX was redesigned and released as the
SWL model SW-5, which was then followed by the 'economy' model, the SW-3.
As Millen describes in his 1931 QST article, most hams favored earphone
operation and didn't use a speaker or need the two extra audio tubes in the
SW-5.

We'll have a real SW-3 tonight, articles and schematics, and parts gathered
so far to make up a duplicate.  Jack will relate his surprising findings at
the last Foothill swap meet.

Hope to see you there!

73 de Bill, AB6MT
ab6mt at sonic.net