OVERVIEW: The AN/FPS-90 radar was a fixed, nodding height finding radar operating in the "E" band

DETAILS:  The AN/FPS-6 was noted for extreme accuracy at long range.  The radar consisted of an antenna group, a transmitter group, a receiver group, and an ancillary group. Most fixed sites had a remote group, which allowed the control of the radar from inside the operations center. Also located in operations, was the anti-jam receivers. These receivers were fed with raw video from the tower receiver, and output several types of processed video to enable operators to see through jamming.

Specifications:

Frequency: 		2.7-to-2.9 GHz (E Band)
Power output: 		3.6 kW(average);  3.5 MW (peak) 4.5 MW (peak prior to downgrade with FPS-6 magnetron)
PRF:			300-405 Hz	
Range Resolution:	300 m (range),  unknown degrees azimuth 					
On/Off time:		unknown
Deploy/Stow Time	N/A
Max Detection Ranges:   370 km 
	

NOTES: The AN/FPS-90 were identical to the AN/FPS-6 except for receiver modifications.  The AN/FPS-90 radar was designated a high-power model and rated at 4.5 MW peak power, versus the AN/FPS-6 at 3.5 MW peak power. Due to maintenance costs and high failure rates, these radars were all retrofitted to the same magnetron as the AN/FPS-6 by the late 1960s, and were no longer high power. The radar maintained its AN/FPS-90 designation due to the receiver modifications.  A mobile version, the AN/MPS-14 was also produced.

SOURCES: Wikipedia. "General Electric AN/FPS-6 Radar" Accessed December 2, 2013. http://en.wikipedia.org/wiki/General_Electric_AN/FPS-6_Radar ; "General ElectricElectric AN/FPS-6 Radar." Wikipedia, the Free Encyclopedia. Accessed March 22, 2015. http://en.wikipedia.org/wiki/General_Electric_AN/FPS-6_Radar ; http://fas.org/nuke/guide/usa/airdef/an-fps-6.htm ; http://www.radartutorial.eu/19.kartei/karte802.en.html