Table 1-2. Capabilities and Limitations (Sheet 5 of 6)

TO 31R2-2GRC171-2

TM 11-5820-815-14

NAVELEX 0967-LP-544-5010

CHARACTERISTIC

SPECIFICATION

TRANSMITTER (Cont)

Output impedance

50 ohms.

Output vswr

1.3:1 or less normal; 3:1 maximum.

Automatic load control (ALC)

ALC maintains the carrier power level between -1 and +1 dB of the rated power

output level at all operating frequencies under normal operating conditions when

operating into load vswr of 3:1 or less.

Modulation

Amplitude modulation to the level of 90% from the following modulation inputs.

Modulation inputs

Main audio:. -15 to +10 dB mW (-35 to -15 dB mW optional), 600/150 ohms,

balanced, ungrounded.

Secure/data audio:

0 dB mW, 600 ohms, unbalanced, grounded.

Microphone:

Dynamic and carbon microphone, low impedance.

Modulation limiting and compression

Automatically limited to 90% maximum and maintained at 80 to 90% for above

modulation inputs; will not overmodulate for inputs above +10 dB mW.

Modulation response

SIGNAL

REFERENCE LEVEL CHANGE

(Hz)

(dB)

Main audio

100

-10 or greater

300

+1, -2

1,000 (ref)

6,000

+1, -2

10,000

-10 or greater

Secure/data audio

+1, -3

1,000 (ref)

25,000

+1, -3

Modulation distortion

10% or less under conditions of 0-dB mW compression; 15% or less under

conditions of maximum compression and limiting.

Sidetone

Detected rf applied to receiver main/headset audio circuits provides at least 100

milliwatts across 600 ohms when transmitter is modulated 90% with a 1000-Hz

tone; level adjustable by a recessed (screwdriver adjustable) control located on

the front panel of the RT-980/GRC-171.

Carrier hum and noise

Not less than 50 dB below a 1000-Hz test tone with transmitter operating at 20-

watt carrier power, 90% modulated.

Harmonic and spurious output

At least 80 dB below level of carrier fundamental.

1-8