MPG-1

TM 11-1366
15 March 1945

Radar set MPG-1 is a mobile, medium range radar unit desinged for use with seacoast artillery. The functions of the radar are:

A. To supply exact present position data on targets within 28,000 yards to gun directors or other gun positioning apparatus.

B. To search for approaching suface craft and to supply data on the rang (distance) and azimuth (direction) of detected targets. The maximum operating range of the equipment is 80,000 yards

C. To supply "splash spltting" data for correcting artillery fire.

Characteristics

Very narrow beam
Uses true sourth as a reference direction
Measures in degrees

Searching:
Continious scan
Sector scan

The beam is swept back and forth automatically over a preselected sector of a circle. The width and position of the scanning sector may be adjusted to include any desired areas within 80,000 yards of the antenna.

Slew Scan

The antenna is made to rotate back and forth, so as to scan a desired sector, by holding a switch alternately in one position and then in another.

Tracking

In tracking a selected target, automatic rotation of the antenna is stopped. The antenna is then rotated only as much as necessary for it to follow the course of the target. However, at this time, the radar beam itself is made to automatically sweep or scan a sector appproximately 10 degrees wide and 2000 yards deep, located anywhere within the 28,000 yards tracking range of the equipment, is then kept under constant observation. By positioning the antenna (with operating handwheels and aided tracking mechanisms) so as to keep the target exactly and continiously in the center of this area, accurate tracking of the target is obtained. The exact range and azimuth of the target may then be read on the indicating dials. Range and azimuth data on the target is also transmitted electrically to a gun data computer wich controls artillery fire.

Indicators

PPI Scope
B-scope - Azimuth - horizontal distnce from the center of the screen. Range - vertical distance from the center of the screen.

Other

Radar - Trailer mounted, can be floated or towed through rough water. Trailer weight of 25,000 pounds which includes the antenna and tower
Remote B-scope in trailer for calling shot and correction of artiller fire.
Transmit, Receive and Rotating feed are housed in antenna assembly. The radiating antenna consists of a plywood shell with a reflector and a built-in horn. The shell houses the remaining components of the antenna. The reflector is hinged to the shell. Adjustable supporting rods at each end of the reflector allow it's angle of tilt to be changed slightly.