Here is a collection of photos of my HB1939 transmitter. I built this with the assistance of Mike N8ECR, Brian W8KHZ and many others.
This transmitter design is from a 1939 "Radio" Handbook, and consists of a pair of Taylor T-200's in PP modulated by a pair of 203Z's. I did the machine work and the building, starting in 2002 and finishing in 2003..
Originally, I used a Collins 32V3 (as a Class C exciter and the 32V3 modulator as the speech amp). In 2010, after we moved, I sold the 32V3. After a couple of attempts, I eventually gave up trying to find the best new exciter to drive it.
Finally, in 2014, Orville, WB8TOT gave me a birthday present. My 1st AM transmitter: a Johnson Viking I. I have modified the speech amp and added necessary circuits to drive the HB1939 "Big Rig". It is back on line and hope to run the DX-60 net with it.
(Submitted by Steve, W8TOW, January 2019)