Functional Block Diagram Description of Receiver Radio R-1467/G-144 Local Oscillator Circuits

TM 11-5820-695-35

circulator 2A10HY1 has a passband frequency range of

bandpass response centered at 70 MHz by resonating

4.5 to 4.9 MHz and provides isolation between the 600-

with the sum of the crystal mixer output capacitance and

4800 MHz frequency octupler and receiver frequency

preamplifier stage Q1 input capacitance. Preamplifier

mixer stage 2A8.

stage Q1 is a fixed tuned, wide band low noise amplifier

stage which determines the noise figure of amplifier-

Bandpass Filter 2FL21. Bandpass filter

mixer 2A7. Preamplifier stage Q2 is also a fixed tuned,

wide band amplifier stage with adjustable gain, R12.

2FL21 passes the 4.55 to 4.85 GHz output from

Preamplifier stage Q3, also a fixed tuned wide band

amplifier-frequency multiplier 2LA10 to receiver

amplifier stage is capable of supplying large signal

frequency mixer stage 2A8. All other frequencies are

levels linearly at the output. Variable capacitor C22 sets

inhibited by bandpass filter 2FL21, thereby improving

the output impedance of amplifier-mixer 2A7 close to 75

the spurious responses of the R1467/GRC-144.

ohms with a minimum reactive component.

Bandpass filter 2FL21 has an impedance of 50 ohms

(nominal) and causes a loss of 0.8 db (maximum) in the

4.56 to 4.85 GHz frequency range.

2-21.

Functional Block Diagram Description of

Receiver

Radio

R-1467/G-144

Local

220 MHz Frequency Multiplier-Osc 2A13.

Oscillator Circuits (fig. 5-19)

220 MHz frequency multiplier-osc 2A13 generates a 220

MHz (70 milliwatts, nominal) output signal which is

Electrical Frequency Synthesizer 2A14.

applied to receiver frequency mixer stage 2A8. The 220

Electrical frequency synthesizer 2A14 is identical to

MHz frequency multiplier-osc 2A18 is comprised of 110

electrical frequency synthesizer 1A14 used in

MHz rf oscillator 2A13Y1 and amplifier-frequency

Transmitter, Radio T-14/GRC-144 (para 2-12 and 2-13).

multiplier 2A13A1. The 110 MHz rf oscillator is a crystal

The 284.375 to 303.125 MHz, 20 milliwatt output of

oscillator which produces a 110 MHz (1500 Hz) output

2A14 is applied to amplifier-frequency multiplier 2A10.

frequency at a power level of 15 milliwatts, nominal.

A detected sample of the output is applied to the

The 110 MHz output signal is applied to input amplifier

SYNTH position of the meter selector switch on meter

Q1 of 2A13A1 where it is amplified and applied to

panel assembly 2A15A2. The SYNTH OVEN indicator

frequency doubler Q2 and Q3. Input amplifier Q1 also

(press-to-test) on meter panel assembly 2A15A2 lights

provides isolation for frequency doubler Q2 and Q3.

white when the oven in 2A14 stabilizes at the correct

Frequency doubler Q2 and Q3 multiply the 110 MHz

temperature. In addition, a synthesizer monitor signal is

input by two producing an output signal of 220 MHz.

applied to alarm-monitor 2A12. This signal indicates if

The 220 MHz output signal is then applied to output

the radio frequency oscillator and the standard radio

amplifier Q4 which amplifies the low level 220 MHz

frequency oscillator both in 2A14, are phase locked.

signal for application to receiver frequency mixer stage

2A8. The 220 MHz output signal from output amplifier

Amplifier-Frequency

Multiplier

2A10.

Q4 is also applied to metering circuit CR3 where it is

Amplifier-frequency multiplier 2A10 receives the

detected for application to the MULT OSC position of

264.3715 to 303.125 MHz signal from 2A14 and

the meter selector switch on meter panel assembly

multiplies (times 16) it up to 4.56 to 4.85 GHz.

2A15A2. Variable resistor 2A15A2R6, mounted on the

Amplifier-frequency multiplier 2A10 is comprised of a

rear of meter panel assembly 2A15A2, is used to

300-600 MHz frequency doubler, 600 MHz amplifier,

calibrate the MULT OSC meter indication.

600-4800 MHz frequency octupler, and a coaxial

circulator. The 300-600 MHz frequency doubler T1,

Receiver Frequency Mixer Stage 2A8.

CR1 and CR2 doubles the 284.375 to 303.125 MHz

Receiver frequency mixer stage 2A8 produces the 4.38

input producing a 568.75 to 606.25 MHz signal. The

to 5.07 GHz local oscillator signal by mixing the 220

568.75 to 606.25 MHz signal is amplified by 600 MHz

MHz signal from 2A16 with the 4.556 to 4.85 GHz signal

amplifier Q1-Q3 sufficiently to drive the 600-4800 MHz

from 2FL21. Receiver frequency mixer stage 2A8

frequency octupler. The 600-4800 MHz frequency

consists of 220 MHz bandpass filter 2A8FL1, crystal

octupler utilizes varactor diode CR8 and octupler plates

mixer 2A8Z1, and coaxial circulator 2A8HY1. The 4.56

L13, L14 and L15 to accomplish a times 8 multiplication.

to 4.86 GHz

The 4.55 to 4.85 GHz (50 milliwatts, nominal) output of

the 600-4800 MHz frequency octupler is sent, through

coaxial circulator 2A10HY1 and bandpass filter 2FL21,

to receiver frequency mixer stage 2A8.

Coaxial

2-48