Technical Characteristics

NAVSHIPS 0967-217-4010

TM 11-5895-490-20

frequency of operation is in the uhf band mak- 3948/APX-72 provide a frame for mounting

ing range dependent on altitude of aircraft.

the RT-859/APX-72 in the aircraft or surface

f. Mountings MT-3809/APX-72 and MT- vessel.

1-5. Technical Characteristics

a. Receiver-Transmitter, Radio RT859/APX72.

Number of modules ----------------- 26

Number of silicon diodes ------- 311

Number of transistors --------------196

Range-----------------------------------Line-of-sight.

Response--------------------------------------Limited by interrogation rate and internal limiting action.

Power requirements ------------- 28 vdc, 70 watts maximum or 28 vdc, 8.4 watts and 115

vac, 95 va maximum, 360-440 cps.

Power source --------------------------28 vdc source or 28 vdc and 115 vac source.

Operating temperature range --- 54 (--65F) to + 95C (203F).

Warmup time ------------------------- 1 minute maximum standard condition.

2 minute maximum extreme service conditions.

Pressurization ---------------------------5 psig at sea level (can operate unpressurized to 30,000

feet).

(1) Receiver:

Type of signal received ------ Pulsed radio frequency.

Frequency ----------------------1030 0.5mc.

Bandwidth -----------------------Minimum 7 mc at 6 db point.

Maximum 25 mc at 60 db point.

Frequency stability ---------- 1.5 mc maximum for a period of at least 500 hours.

Sensitivity:

Normal triggering level --- Between 69 and 77 db below 1 milliwatt.

Low triggering level ------ Between 52 and 67 db below 1 milliwatt.

Random triggering rate ------- Maximum of five replies per second averaged over a one-

minute period.

Triggering bandwidth ------ 2.5 mc at 3 db points.

(2) Transmitter:

Type of signal transmitted -- Pulsed radio frequency.

Frequency --------------------------- 1090 0.5mc.

Frequency stability ------------- 3 mc maximum drift.

Peak power output ---------------- 500w 3 db.

Duty cycle ---------------------------- 1.1 percent maximum.

Delay ----------------------------------- 3.5 5 sec between the leading edge of the second inter-

rogation pulse to the leading edge of the first reply

pulse.

Spurious responses --------------------- Maximum of 60 db down from the aplitude of trans-

mitted pulse.

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