OVERVIEW:  The RP-21M Sapfir aka SPIN SCAN-B aka TsD-30TK aka Izdeliyie 830M 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:		870-945 pps (search) 1785-1805 (track)
	Pulse width:	0.4-1.2 ms (search); 0.2-0.7 ms (track)
	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 vacuum 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); NATO "Current Soviet Bloc Electronic Equipment, Vol B: Airborne" dtd 12 Feb 1968, https://archives.nato.int/uploads/r/nato-archives-online/3/e/d/3edb1c40c2fa5a07ebce2f98f8260bff2d0cecdaae105c6b14c4c419fc036b1d/MC_0262_B_67_FINAL_ENG_PDP.pdf




