[Central-Electronics] unerstanding the 20A

[Robert Nickels]

On 4/6/2011 12:48 PM, Jimmy Green wrote:
> books or information I might find that would help me to gain a good foundation.
>
Great question Jimmy.   I'll start with suggesting that you pick up the 
"New Sideband Handbook" by Don Stoner W6TNS that was initially published 
by CQ in 1958.  It's easy to read with lots of examples and has a full 
chapter devoted to the phasing method.   Secondly, copies of the ARRL 
"Single Sideband for the Radio Amateur", published from the mid-50s 
through the early 70s.  Various editions, but each has useful 
information.  And if you're an ARRL subscriber, there are plenty of 
articles on phasing SSB , starting with the initial patented design of 
Don Norgaard that appeared in June '48 can be downloaded from the ARRL 
website archive.

And online for free (courtesy N4TRB)  you can now find the very useful 
"GE Ham News" collection - or to cut to the chase for early SSB - the GE 
Ham News Sideband Handbook:  
http://n4trb.com/AmateurRadio/GE_HamNews/sideband_handbook.htm

Of particular interest is the "SSB Jr" article, which was written by 
Norgaard (W2KUJ) as a simple and reproducible version of his phasing 
exciter.  He worked as a research engineer at GE and his original 
patents were licensed to Central Electronics, Lakeshore, another early 
phasing SSB manufacturers who commercialized this design.  Once you 
understand the simple one-band SSB Jr.  you will have a good basis for 
understanding the more complex bandswitching 20A that's built on the 
same basic platform.

73 and have fun, this is all great stuff!

Bob W9RAN