View source for P-3 radar

{{Short description|Radar station}}
{{Infobox Radar 
|name        = P-3 radar
|image       = Dumbo radar.png
|caption     = [[CIA]] illustration of a P-3
|country     = {{flagcountry|Soviet Union}} 
|introdate   = 1947
|number      =
|type        = Early Warning Ground Control
|frequency   = VHF
|range       = 120-150 km
|altitude    = 10 km
|diameter    = 
|azimuth     = 360 degrees
|elevation   = 4-18 degrees
|precision   = 1.5 km range, 4-degree azimuth and 1.5-degree elevation
|power       = 80-100 kW
}}

The '''"Pegmantit 3"''' or '''P-3''' (also referred to by the [[NATO reporting name]] '''"Dumbo"''' in the west) was an early [[VHF]] [[radar]] developed and operated by the former [[Soviet Union]].

==Development==
The "Pegmantit 3" which is abbreviated to P-3 was one of the first 2D early warning and ground control radars to be developed by the former [[Soviet Union]]. The development of the radar was initiated in 1943 as a replacement for the previous RUS stations used during the [[Second World War]]<ref name="PVO">{{cite web |url=http://pvo.guns.ru/rtv/nitel/p3.htm |title=РЛС П-3А (Dumbo) |language=ru |access-date=2008-12-24 |date=2004-02-24 |publisher=pvo.guns.ru }}</ref> and by the end of 1947 the radar was completed and in operational service.<ref name="NNIIRT"/> The P-3 was the first radar to be developed by the SKB Design Bureau, a division of State Plant No.197 named after [[Lenin|V. I. Lenin]], the predecessor of the current [[NNIIRT|Nizhniy Novgorod Research Institute of Radio Engineering]] (NNIIRT).<ref name="NNIIRT">{{cite web |url=http://www.nniirt.ru/ |title=Nizhniy novgorod research institute of radio engineering |access-date=2008-12-24 |date=2008 |publisher=NNIIRT }}</ref> The radar had to be able to detect an aircraft to a range of no less than 130 kilometers, cover 360 degrees in azimuth and 4-18 degrees in elevation. A response time of no more than 25 seconds was stipulated and the radar had to be accurate to within 650 meters in range and within 700 meters in altitude, as well as operate in the VHF band.<ref name="PVO"/> SKB managed to meet these performance requirements with the P-3 radar and this was confirmed during testing in 1945 before entry into service with the [[Soviet Air Defence Forces|PVO]].<ref name="PVO"/>

==Description==
The P-3 was produced in two variants the P-3A (fixed) and the P-3M (mobile) with a [[transmitter]] and [[Receiver (radio)|receiver]] mounted on separate trucks.<ref name="RB">{{cite web |url=http://www.radartutorial.eu/19.kartei/karte903.en.html |title=P-3 "Dumbo" |access-date=2008-12-24 |date=2008 |author=Christian Wolff }}</ref> Both variants operate in a similar fashion using two mast mounted [[Antenna (radio)|antenna]]s (transmitter and receiver) composed of [[Yagi antenna]]s mounted one above the other in the case of the receiver, the radar also used an [[Radar display#A-scope|A-scope]] display. Azimuth was scanned mechanically by the receiver antenna with elevation determined using a [[Goniometer]], the [[phase (waves)|phase]] difference between the upper and lower Yagi antenna was used to calculate the elevation angle which could then be used to determine the height of the target once the range was known.<ref name="RB"/> The P-3 had a maximum power output of up to 100&nbsp;kW and a pulse duration of 10-15 microseconds.<ref name="PVO"/>

==Operators==
The P-3 was operated by the Soviet Union from 1947<ref name="PVO"/> but has long since become obsolete and retired from service, replaced by more advanced models entering into service after the P-3 such as the [[P-8 radar]].

==See also==
*[[P-8 radar]]
*[[List of radars]]
*[[Russian air surveillance radars]]

==External links==

*[http://www.nniirt.ru/ NNIIRT]

==References==
{{reflist}}
{{Russian and Soviet military designation sequences}}{{Soviet and Russian radars|state=expanded}}{{DEFAULTSORT:P-03 Radar}}
[[Category:Soviet military radars]]
[[Category:Nizhny Novgorod Research Institute of Radio Engineering products]]
[[Category:Military equipment introduced from 1945 to 1949]]