The popular WWII "Command Set" transmitters which have been
collectively known as "ARC-5" actually include transmitters
from three very different sets:
the Navy ATA, the Army SCR-274N and the Joint Army/Navy
(though almost exclusively used by the Navy) AN/ARC-5.
The ATA and SCR-274N transmitters are electrically identical,
but the later AN/ARC-5 is very different. Many of these fine
transmitters were destroyed because a ham had the wrong
diagram, having been told they were all "ARC-5s."
Many of our community are new to these differences,
so I've written this short "primer" to assist in correctly identify the sets.
Will make one for the receivers soon.
GL ES 73 DE Dave Stinson AB5S