OVERVIEW:  The RP-21M Sapfir aka SPIN SCAN-B aka TsD-30TK radar is an airborne air-to-air fire-control radar operating in the NATO I band.

DETAILS: 
 The RP-21M  radar is a single conical scan antenna. The radar had jamming protection, a roll-stabilized antenna and a larger position display. Additionally, it had a fixed-beam target illumination function, which allowed use of K-5 AAMs. It lacks a LD/SD capability.  It was also limited against low level targets, with its ranged reduced to 2.7 nm for targets below 6,600 feet, and not capable of tracking targets below 3,300 feet. 		


Specifications:

	Frequency:	9 GHz (approx) (I-band (NATO))
	PRF:		??Khz
	Pulse width:	??
	Power: 		 60 kW (peak) 
	Scan Limits:	30 ° azimuth, ±12 ° elevation.
	Range:		11/8nm search (bomber/fighter aircraft)
			6.5/5 nm tracking (bomber/fighter aircraft)
			
NOTES:  IOC 1964.  Exported after 1966. Used vaccum tubes, resulting in a low mean time between failures, but high resistance to EMP effects 

SOURCES: Mladenov, Alexander. Soviet Cold War Fighters. Fonthill Media, 2017, location 3497 (Kindle ed.) ; Jane's Radar and Electronic Warfare Systems, "Sapfir Series Radars," 19 October 2000; "1.1.2 Capabilities - Soviet Aircraft Tech." Google Sites. Accessed April 26, 2022. https://sites.google.com/site/sovietaircrafttech/mig-21/rp-21-sapfir-manual/1-1-2-capabilities; Mladenov, Alexander. Mikoyan-Gurevich MiG-21 (Air Vanguard)(Kindle ed., pg. 44-45)




