CESL                                                                                S E C R E T                                               August 1943

424A                                     RADIO SET SCR-548.

DESCRIPTION: A 600-mc mobile early-warning aircraft detector. Easily convertible
to SLC by the addition of a rotating dipole and another “A” type oscilloscope to
provide double tracking in azimuth and elevation. Normal display equipment:
combination 12-inch PPI and 5-inch “A” type oscilloscopes. Range 120 miles.

MILITARY CHARACTERISTICS: Proposed by Army Air Corps in letter to OCSigO,
1 Mar. 43, file AFTSC/MCG-1, subject: “SCR-548 Portable Ground Radar.”

Progress:

1. General.

a. The Breeze Corporation has begun the construction of
the mount for Radio Set SCR-548. It is expected that the
first model will have Westinghouse (AF-2) antenna drive
controls. A new single console type of antenna drive control.
unit is under development for this set by the manufacturer.

b. A console indicator containing a 12″ PPI and three
5″ “A” tubes is in the process of design for use with this set.

424B                                     PROTECTED SYSTEM (RADIO SET AN/CPS-2).

DESCRIPTION: An early-warning radio set employing a continuously variable
frequency in the 510 to 725-mc band to minimize enemy jamming. Provides PPI and
type “A” presentations. Maximum range approximately 100 miles.

MILITARY CHARACTERISTICS (Proposed): Incl. to 3rd Ind., from OCSigO, file SPSRB
418.44 AN/CPS-2, dated 8 Aug. 43, subject: “M/C for protected Radar.”

Progress:

1. General.

a. Under authority of Purchase plan 2239, Laboratory
Purchase Division has issued a Letter Contract W 3434 sc-730,
Order No. 424-CEGSS-44, to Federal Telephone & Radio Corporation,
67 Broad Street, New york City, for one model of Radio Set
AN/CPS-2, to be produced in accordance with joint Army-Navy
tentative specification. LPD has indicated that the ordering
of spare parts cannot be completed until 30 days prior to the
anticipated delivery of the set, which is expected to be on
or about 5 April 1944. OCSigO has submitted revised military
characteristics on subject equipment to this Laboratory,
requesting comments and recommendations. This Laboratory has
recommended that the original military characteristics be
used for the development procurement, and that the military
characteristics be completely rewritten for production sets.

b. Radio Set AN/CPS-2 will conform to the general IFF
plan for Radar equipment inasmuch as a radio equipment similar
to the Radio Equipment RC-184 will be used for this set. This
will eliminate any need for interconnection to the Radar and
will furnish both azimuth and range information.

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CESL                                                                                S E C R E T                                               August 1943

424C                                   ROAD MOBILE EARLY WARNING RADIO SET (AN/MPS-I)

                                           AUTHORIZATION: 2nd wrapper Ind., from OCSigO to CESL, dated 10 July 43, file
SPSRB 413.44 AN/MPS-1, on basic letter dated 14 June 43 from Army Air Forces
to OCSigO.

MILITARY CHARACTERISTICS (Tentative): Submitted by OCSigO in 2nd wrapper Ind.,
mentioned in above authorization.

DESCRIPTION: A mobile early-warning Radar to operate in the band 1280 – 1350 mc.

Progress:

i. General.

a. By direction of the Chief Signal Officer the project
for Radio Set AN/MPS-1 has been canceled.