The Atlas 180 and 21x series
Here are Diagrams PC100-PC400.
See also the main chassis diagram.
To save any of these diagrams, right -mouse-click on it and choose "save picture as..".
The block diagram, click on it for a bigger view.
PC100 card circuit. First Mixer, first I.F.
PC200 card. 2nd IF, 2nd mixer, mic amp and s-meter amp.
PC300 card. Rx audio, oscillator and switch.
Note: The numbering is reversed from that on the chassis plan!