[ARC5] B&W 350 Phase Shift Network for W2EWL SSB rig

[Robert Nickels]

As a big fan of phasing type SSB,  I thought it might be of interest to 
some that the math and engineering work behind this type of audio phase 
shift network was done by Robert B. Dome of the General Electric 
Receiver Division.   No computers, just slide rules and brainpower back 
then, but his design provided a 90 degree phase shift with less error 
across the band of frequencies needed for transmitting speech.   It's 
described in his article "Phase Shift Networks" in Electronics magazine 
for Dec. 1946, which can be found at the World Radio History site.

Dome's design was the basis for the Barker and Williamson 350 / 2Q4 
network that was affordable enough for the countless hams who followed 
the example of Tony Vitale W2EWL to create their own SSB transmitters,  
both based on modifying plentiful and cheap ARC-5 transmitters  and in 
homebrew designs.  His design was also produced by Central Electronics 
and other comopanies in different form - even Millen made one!

Dome, aka W2WAM, is also credited for many technical innovations at GE, 
including frequency interlace color television modulation, which was 
compatible with existing black and white television sets but was not 
selected as the industry standard.

73, Bob W9RAN
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