May 022006

Radar Set AN/PPS-6 is a lightweight non-coherent pulse Doppler combat surveillance radar operating in the X band between 9.0-9.5 GHz. When set up on its tripod, it allows the operator to detect moving objects at ranges of up to 1,500 meters (people) or 3000 meters (vehicles). The operator can measure the target range with a resolution of 50 meters. Transmitted RF power is generated by a magnetron tube, and the receiver local oscillator uses a klystron tube. It transmits pulses at a rate of about 2,000 pulses per second with a peak power of at least 100W and a width of 0.22-0.30 microseconds. An azimuth motor allows automatic scanning, and the motor may be disengaged for manual aiming. There is no display screen; the operator listens for the returned Doppler-shifted tone in the headphones, and reads out range on a mechanical counter after dialing in the range gate with a hand crank. The antenna is a 12 inch diameter truncated parabolic dish. The set operates either from an internal 12V silver-zinc rechargeable battery or an external 12VDC source.



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Personnel Detection Range (0.5m2 target) 50 to 1500 meters
Vehicle Detection Range (10m2 target) 50 to 3000 meters
Range Accuracy ±25 meters
Range Resolution 50 meters
Range Gate Width 45 meters
Azimuth Coverage 0 to 6400 mils (clockwise and counterclockwise)
Azimuth Accuracy ±18 mils
Azimuth Resolution 155 mils
Automatic Area Search A 315m or 600m range depth is scanned in an azimuth range of 600, 900 or 1200 mils.
Elevation Coverage +400 mils to -600 mils
Elevation Accuracy ±18 mils


Transmitting System

Frequency Range 9.0 to 9.5 GHz
Pulse Rate 1800-2200 pulses per second
Peak Power 100W min.
Pulse Width 0.22 to 0.30μs
RF Power Source Magnetron, Varian BLM-003


Antenna System

Transmission Line Section of RG-52/U waveguide equipped with a choke-type input flange
Radiating Element Slotted waveguide
Reflector Truncated parabolic, 12″ diameter
Antenna Gain 24.5dB min.
E-plane Beamwidth (3dB point) approx. 7°
H-plane Beamwidth (3dB point) approx. 8°
Sidelobes Not less than 13dB attenuation


Receiving System

Type Superheterodyne
Operating Frequency 9.0 to 9.5GHz (tunable)
Local Oscillator Tube Type Klystron, Varian VA203B
Local Oscillator Frequency 30MHz below magnetron frequency
Crystal Protection Solid-state limiter
Intermediate Frequency 30MHz ±2MHz
Intermediate Frequency Bandwidth 6.3MHz ±0.6MHz at 3dB points
Intermediate Frequency Gain 80dB min.
Intermediate Frequency Manual Gain Control 40dB min.
Audio Bandwidth 26 to 1000Hz
Minimum Discernible Signal (MDS) -95dBm


Indicating System

Headset Aural detection and identification
Test Meter Visual indicator
Range Indicator (mechanical counter) Range readout in meters
Elevation Indicator (dial) Elevation angle readout in mils
Azimuth Indicator (dial) Direct azimuth reading in mils (0-6400)


Antenna Positioning System

Azimuth Drive System Sector scan motor, 2200RPM reduced through gearing to approx. 3RPM
Automatic Sector Scan Area 300, 450 or 600 mils left and right of a predetermined position set by the sector scan ring
Manual Sector Scan Area Manual scanning performed by operator from 0-6400 mils
Azimuth Scan Rate 58 mils/second nominal
Azimuth Scan Motor 12VDC permanent magnet gearhead motor
Elevation Manual tilt, +400 to -600 mils


Power Source

Type Self-contained 12V silver-zinc battery or external 12VDC source
Power 15.7W max. at 12VDC input


  7 Responses to “Radar Set AN/PPS-6”

  1. send me a picture of the wave guide output connector and I will see if I have an adapter to coax…Jay Simmons K6RIY

    • This picture above shows the wave guide connector. The wave guide itself is probably some common size, but the flange is a twist-lock fitting which is probably custom. The test adapter I’m looking for is intended to fit into the waveguide output at the center of the dish, in place of the normal feedhorn which is sitting on top of the unit in that picture. If and when I ever get around to playing with this radar again, I may just need to fabricate an adapter.

  2. Now that I know what it looks like, I can search through the channel 11 obsolete microwave stuff. Jay

  3. Just found this web page. Brings back memories. In 1969-1970 I repaired dozens of “Pippsy Sixes” when I was at 3rd FSR, Camp Foster, Okinawa. While I don’t have one, the test coupler your looking for is a closed waveguide section with a matching twist lock on one end, and an N connector with 1/4 wave stub inside the waveguide at the other. The N is mounted on the waveguide width, 90 degrees to the wide side. As I recall, the coupler is about 4-5 inches long.
    I used an X band radar test set, TS-147, for transmitter and receiver test and adjustment. Years ago I bought a TS-147 at a swap meet for a few bucks. It worked then and probably still does. If the mixer attenuator ever quits due to loss of the silver plating on the movable quartz plate, let me know. There is a cheap way I used to fix the missing silver that worked just fine. Anyway thanks for the memories.

  4. In 1953 the US Army had a portable ground surveillance or battlefield radar tested in Korea. They were tested in an ROK sector and almost lost due to combat. My guess it was an early version of the AN/PPS3,4,5 family line of radars.
    See basic story at:

    Any idea what this radar unit was called or designated? Or a picture?

    Any help appreciated. Thank you.