Transmitter, Radio T-1054(P) /GRC-144(V) Local Oscillator and Mixer Circuits Functional Block Diagram Description

TM 11-5820-695-35

frequency multiplier in lA10. Coaxial circulator 1HY1

2-11.

Transmitter, Radio T-1054(P) /GRC-144(V)

also provides a detected sample of the 1137.5 to 1212.5

Local

Oscillator

and

Mixer

Circuits

MHz signal (1st multiplier) to the meter selector switch

Functional Block Diagram Description (fig.

on meter panel assembly lA15A8. Variable resistor

2-3)

1A15A8R4 on the back of meter panel assembly

1A15A8 is used to calibrate the 1st multiplier

The local oscillator circuits consist of electrical

(AMPLMULT) meter indication.

frequency synthesizer 1A14, transmitter amplifier-

(2) Transmitter frequency multiplier group

frequency multiplier 1A11, coaxial circulator 1HY1, and

lA10 is comprised of transmitter 2nd stage frequency

transmitter frequency multiplier group 1A10. The local

multiplier lAlOA1, coaxial circulator lA1OHYl, and

oscillator circuits produce a 4.55 to 4.85 GHz output

transmitter 3rd stage frequency multiplier 1AlA2. The

which is applied to transmitter frequency mixer stage

transmitter 2nd stage frequency multiplier 1A10A2

1A9 along with the frequency modulated 150 MHz

employs a tuned circuit, a varactor diode doubler and a

output from radio transmitter modulator 1A8. The mixer

tuned cavity to multiply the frequency up to 2275-2425

circuits consist of crystal mixer 1A9Al and coaxial

MHz at 4 watts (nominal). Coaxial circulator lAlOHY1

circulator LA9HY1 in frequency mixer 1A9 The mixer

isolates transmitter 2nd stage frequency multiplier

circuits hetrodyne the local oscillator frequency with the

1A10A1 from transmitter 3rd stage frequency multiplier

150-MHz signal to produce a 4.4 to 5.0 GHz output

1A10A2 and also provides a detected sample of the

which is applied to the antenna system through rf

2276 to 2426 MHz signal (2nd multiplier) to the meter

bandpass filter 1FL3, rf low-pass filter 1FL4, and

selector switch on meter panel assembly lA15AS.

directional coupler 1DCl.

Variable resistor 1A'15A8RS on the back of meter panel

a. Local Oscillator Circuits. The local oscillator

assembly 1A15A8 is used to calibrate the 2ND MULT

circuits produce an output frequency of 4.55 to 4.85

meter indication.

Transmitter 3rd stage frequency

GHz by multiplying the electrical frequency synthesizer's

multiplier 1A10A2 employs a low pass filter, varactor

output frequency by 16.

Electrical frequency

diode doubler, and a tuned cavity to multiply the

synthesizer 1A14 generates a highly stable radio

frequency up to 4.55-4.85 GHz at 1.7 watts (nominal).

frequency in the range of 284375 to 303.125 MHz,

The 4.55-4.85 GHz signal is applied to transmitter

adjustable in 6.250 kHz steps. Electrical frequency

frequency mixer stage 1A9 where it is mixed with the

synthesizer 1A14 circuits are described in detail in

frequency modulated 1150 MHz signal from radio

paragraph 212. The 284.375 to 303.125 MHz, 20

transmitter modulator LA8.

milliwatt output of electrical frequency synthesizer lA14

is applied to transmitter amplifier-frequency multiplier

b. Transmitter Frequency Mixer Stage 1A9.

1A11.

Transmitter frequency mixer stage 1A9 translates the

frequency modulated 150 MHz signal up to the 4.4 to

(1) Transmitter amplifier-frequency multiplier

5.0 GHz band. This is accomplished by heterodyning

1All is comprised of frequency doubler stage 1 CR1 and

the local oscillator frequency of 4.55 to 4.85 GHz with

CR2, 600 MHz amplifier stages Q1 Q4, and frequency

the 150 MHz signal in a tuned varactor cavity.

doubler stage 2 CR3. The 284.375 to 303.125 MHz

Frequency conversion is accomplished by the nonlinear

input is doubled to 568 750 to 606.250 MHz by

capacitance-voltage relationship of the varactor diode in

frequency doubler stage 1 and applied to the 600 MHz

the tuned cavity.

amplifier stages. The 600 MHz amplifier stages amplify

the 568.750 to 606.250 MHz signal to a level

(1) The frequency mixer circuits consist of

(approximately 18 watts) to drive frequency doubler

crystal mixer lA9Al and coaxial circulator 1A9HY1. The

stage 2. Frequency doubler stage 2 doubles the signal,

4.665 to 4.85 0Hz local oscillator signal enters port

1137.5 to 1212.5 MHz. The 1'187.5 to 1212.5 MHz

number 1 of the circulator and leaves at port number 2,

signal (approximately 8 watts power output) is applied to

entering tuned varactor cavity Z1 in crystal mixer

transmitter frequency multiplier lA10 through coaxial

1A9A1. The 150 MHz signal is applied at the opposite

circulator 1HY1.

The circulator isolates frequency

end of the tuned varactor cavity by the 150 MHz tuned

doubler stage 2 in 1All from the transmitter 2na stage

circuit.

Change 6 2-30