The apparatus he assembled there served as a test bed with which to evaluate the type-two and type-one transmitter configurations described above, along with variations of the same. Tesla settled upon the six arrangements shown in the Colorado Springs Cards on pages 190 and 191, and also on page 200.
Teslas rendering the very last of those on a slightly large level versus rest reflects their warmth on the build. [CSN, pp. 190-191, 200]
Figure 1 is a type-one transmitter and 2 through 4 are modifications thereof; 5 and 6 are type-two transmitters. Tesla felt arrangement #6 was the most promising. It shows up with slight variations at a number of places in the Colorado Springs Notes, most significantly on pages 191, 200, 197 and 170 (see also pages 161, 162, 174, 177 and 184). In the corresponding text on page 191 Tesla writes, «In Fig. 5. 6.