Amplifier-Frequency Multiplier 2A10 Circuit Functioning

TM 11-5820-695-35

Q4 is applied to the 600 to 3800 MHz octupler

frequency is in the range of 4.33 to 5.07 GHz;

stage via cable W1. Matching is accomplished by C17,

conversion loss does not exceed 12db relative to the

L12, C18, and C19.

220 MHz signal input level thereby producing an output

level of above 0 dbm nominal at connector J2 RF

OUTPUT.

c. 600 to 4800 MHz Frequency Octupler.

This stage multiplies (times 8) the amplified 568.750 to

c. Crystal Current Metering Circuit. The crystal

606.250 MHz signal up to 4.55 to 4.85 GHz. The

current metering circuit consists of L1, C1, R1, R2, C3,

frequency multiplying (times 8) action is achieved by

L2 and FL2 in one mixer diode metering branch and L3,

varactor diode CR3. The input circuit consists of

C5, R3, R4, C6, L4 and FL3 in the other mixer diode

capacitors C20, C21, C23, C28, and inductor plates L13

branch. Capacitors C2 and C4 provide coupling of the

and L14. Resistor R13 provides bias for varactor diode

220 MHz signal into crystal mixer 2A8Z1.

CR3. The input circuit is tuned to the 568.750 to

606.250 MHz input signal. The output circuit (C22, C29,

L15) is tuned to the eighth harmonic of the input

d Crystal Circulator 2A8HY1. Coaxial circulator

frequency. The 4.55 to 4.85 GHz. output signal (70

2A8HY1 has a bandpass of 4.33 to 5.07 GHz with a

milliwatts, nominal) is fed through circulator HY1 to the

maximum insertion loss of 0.8 db.

The 2A8HY1

HY1J2 OUTPUT connector. Circulator HY1 provides

provides 18db isolation from port J2 output to port J1

isolation between the 600 to 4800 MHz frequency

input. A resistive termination is incorporated at port 3 to

octupler circuit in 2A10 and the receiver frequency

dissipate the rejected sideband from local oscillator

mixer stage 2A8.

bandpass filter 2FL6.

2-74. AF-RF Amplifier 2A11 Circuit Functioning (fig.

2-73. Amplifier-Frequency Multiplier 2A10 Circuit

2-13)

Functioning (fig. 5-7)

Amplifier-frequency multiplier 2A10 amplifies and

Af-rf amplifier 2A11 is a wide band video amplifier and

multiplies (times 16) the 284.375 to 303.125 MHz (20

is identical to af-rf amplifier 1A4 used in the T-

milliwatts, nominal) input signal to a 4.55 to 4.85 GHz

1054/GRC-144. The circuit theory description provided

(70 milliwatts, nominal) output signal.

Amplifier-

in paragraph 2-31 for af-rf amplifier 1A4 also covers af-

frequency multiplier 2A10 is comprised of a 300 to 600

rf amplifier 2A11 with the following exceptions: (1) The

MHz frequency doubler, a 600 MHz amplifier, and a 600

composite pcm and orderwire signal from 1.0 MHz low

to 4800 MHz frequency octupler.

pass filter 2A3 is applied to J1 IN and is amplified; (2)

the orderwire input (P1-8) is not used; (3) the amplified

a. 300 to 600 MHz Frequent Doubler. The 284.375

output (composite pcm and orderwire signal) is applied

to 303.125 MHz signal from electrical frequency

to digital data (modem 1A12 via J2 OUT; and (4) the

synthesizer 2A14 is applied to the primary of

alarm output (P1-9) is used (the amplified pcm and

transformer T1 through connector designated J1 INPUT.

orderwire signal is routed to alarm monitor 2A12 via P1-

The secondary of T1 is connected to the anodes of

9).

diodes CR1 and CR2. This circuit is, in effect, a full-

wave rectifier, in which CR1 and CR2 alternately pass a

half cycle of the input signal. The fundamental output

2-75. Alarm-Monitor 2A12 Circuit Functioning (fig.

(568.750 to 606.250 MHz) is twice the input frequency

2-14)

and is coupled to the base of Q1 in the 600 MHz

a. Alarm monitor 2A12 is identical to alarm monitor

amplifier circuit through variable capacitor C1.

1A5 used in the T-1054/GRC-144; however, the jumper

connections on the associated plate assembly

b. 600 MHz Amplifier. The 600 MHz amplifier

connectors for each assembly are different. The circuit

consists of transistor stages Q1 and Q2 which operates

functions of alarm monitor 1A5 are described in

as low level class A amplifiers in the common emitter

paragraph 2-32. The following paragraphs describe the

configuration. Transistor stage Q3 is a power amplifier

circuit functions of alarm monitor 2A12.

and operates class C. Capacitors C3, C4, C10 and C11

b. The low level traffic monitor input signal is

are emitter bypass capacitors and adjustable resistor R7

amplified by integrated circuit operational amplifier AR1

in the emitter circuit of Q2 permits adjusting the gain.

(fig. 2-14, part 3). The inverting

The output of Q2 is coupled to the base of Q3 through

capacitors C13 and C14. The output of

2-116