CHAPTER 11. AMPLIFIER, RF AM-3979/FR-93

TM 11-5820-554-12

CHAPTER 11

AMPLIFIER, RF AM-3979/FR-93

Section I. INTRODUCTION

11-1. General

Type of service ..........................

Ssb-continuous voice modulation.

This chapter describes Amplifier, RF AM-3979/ FRC 93

Cw-50

percent

duty

(Collins 30L-1). This amplifier is used to increase the

cycle(continuous

keydown

conditions not to exceed 30

output of the AN/FRC-93 to 1,000 watts and allows

seconds duration).

communication over greater distances. It is portable,

Plate power input.......................

Cw-1,000 watts.

but can be used in a mobile station by mounting it on a

Ssb-nominal pep input of 1,000

Collins 351E-4 mounting plate.

Case, Electrical

watts with speech. Third order

distortion products at this level

Equipment CY-6197/ GRC-159 is used for carrying the

are at least 30 db down from

amplifier in port" able applications.

signal.

Drive power requirememts

70 watts.

230 volts a.c. 10%, 3 wire, single

Primary power requirements .....

11-2. Tabulated Data

phase,

7.5

amperes

maximum, or 115 volts a.c.

10%

amperes

Frequency range ........................

3.6 to 29.7 MHz covering all

maximum, 50 to 400 Hz.

amateur bands. By retuning

Operation

from

line

input coils as necessary, the

frequency other than 50 to 60

following

general-coverage

Hz requires an auxiliary 60-Hz

bands may be covered:

supply for a fan motor.

Input impedance ........................

52 ohms.

Frequency

Total coverage

Output impedance .....................

52 ohms unbalanced with vswr not

band

to exceed 20 to 1 on the

3.5 MHz

3.4 to 5.0 MHz

amateur bands.

7.0 MHz

6.5 to 9.5 MHz

Noise level

40 db down from output signal

14 MHz

9.5 to 16.0 MHz

with 1 kilowatt single-tone

21 MHz

16.0 to 22.0 MHz

input.

28 MHz

22.0 to 30.0 MHz

Harmonic output .......................

All harmonics at least 40 db down

Mode..........................................

Ssb or cw.

from output signal.

11-3. Items Comprising an Operable Amplifier, Radio Frequency AM 3979/FRC-93

NSN

Item

Dimensions

Weight

Height

Depth

Width

5820-00-082-4081

Amplifier, Radio Frequency, AM-3979/FRC-93 (Collins 30L-1)................

6 9/16

14 3/4

Section II. INSTALLATION

11-4. Unpacking

Carefully remove the packing material. Examine for

amplifier against table 11-1. Lift the amplifier

visible damage. If the amplifier has been damaged

cabinet lid. Loosen the 10 screws in the RF

in shipment, refer to paragraph 1-3. Check tuning

compartment cover, slide it forward, and lift it off

controls and switches for freedom of action. Check

Remove the packing material around the tubes.

the equipment included with the

Replace the cover and tighten the screws. Lower the

lid.

11-1