FPS-90

 Long Range Height Finder Radar Set - A Long Range Height Finder Radar set developed at RADC and built by General Electric.

The FPS-90 was a long range, high power, air transportable, height finding radar used in conjunction with a long range search radar set. The basic components for the FPS-90 came from the FPS-6, FPS-6A and FPS-6B. The differences with the FPS-6 series were:
 * Removal of the variable nod functionality in the FPS-6B models.
 * Replacement of the magnetron with a higher power QK-338A magnetron.

The FPS-90s (and FPS-6s) were used in the SAGE System to provide height data for targets selected by the direction center. The direction center would preposition the height-finder through the FST-2 and an operator would verify the target and transmit the correct altitude back to the direction center. The Range Height Indicators (RHI) of the FPS-90 were used to find the target and a cursor would be positioned at the correct altitude.

FPS-90 Height Finder Radar
See Also:
 * FPS-6
 * FST-2
 * US Radar Sets

Sources:
 * MIL-HDBK-162A, 15 Dec 1965.
 * MIL-HDBK-162A, 15 Dec 1965.

Links:
 * Radomes - FPS-90