Frequency Control Circuits-continued

TM 11-5820-509-35

provide isolation that enhances overall frequency

KILOCYCLES indicator

Pulse amplifier Q19 output

stability. Locked oscillator Q4 divides the output of the

reading

frequency (MHz.)

3-MHz oscillator by six times to provide the 500-kHz

XX000 to XX099

1.8

standard signal. Part of this output is routed through

XX100 to XX199

1.7

follower Q7 to locked oscillator Q8 where it is further

XX200 to XX299

1.6

divided by five to obtain the 100-kHz output signal. This

XX300 to XX399

1.5

latter signal is amplified by 100-kHz amplifier Q9 before

XX400 to XX499

1.4

being applied to the 100-kHz pulse generator circuits of

XX500 to XX599

1.3

oscillator control A7. The remaining portion of the

XX600 to XX699

1.2

output from locked oscillator Q4 is amplified by 500-kI]z

XX700 to XX799

1.1

amplifiers Q5 and Q6 before being routed to the

XX800 to X X899

1.0

receiver-transmitter circuits as the 500-kHz standard

XX900 to XX999

0.9

signal. Part of the output of Q5 is converted to 1-M Hz

by frequency doubler Q4 in oscillator control A7. This

limiters Q17, Q18, and Q19. The spurious frequencies

sinousoidal signal is applied to pulse generator Q5-Q6

introduced in the output by this limiting are removed by a

where it is converted to a 1-MHz pulse-train that is

filter and the remaining signal is routed to follower Q24.

subsequently amplified by Q7 before application to

The 1.8- to 0.9 MHz output of Q24 is heterodyned with the

pulse amplifier A19 in signal data translator A3. The

5- to 14-MHz output from follower Q18 in signal data

output circuit of Q19 is a parallel-resonant tuned circuit

translator A6 in diode quad mixer CR10. The difference-

that is selectable in 1-MHz increments between 5- and

frequency that results from this mixing is a single 100-kHz

14-MHz as shown below. Depending upon the selection

frequency between 3.2 and 13.1 MHz as shown in the

made by the frequency control knobs on the front panel

following table. This signal frequency is routed through

of RT-671/PRC-47, one whore megahertz channel in

follower Q25 to diode quad mixer CR11 where it is mixed

this range is made available to the subsequent circuits.

with the hf oscillator output signal that was generated by

A constant amplitude signal is assured by passing this

selected frequency through limiters Q16 and Q17 before

KILOCYCLES

Mixer CR

KILOCYCLES

Mixer CR10

application to follow er Q18.

indicator

output

indicator

output

reading

(MHz.)

reading

(MHz.)

KILOCYCLES indicator

Pulse amplifier Q 19 output

2000 to 2099

3.2

5500 to 5599

6.7

reading

frequency (MHz.)

2100 to 2199

3.3

5600 to 5699

6.8

2000 to 2999

5.0

2200 to 2299

3.4

5700 to 5799

6.9

3000 to 3999

6.0

2300 to 2399

3.5

5800 to 5899

7.0

4000 to 4999

7.0

2400 to 2499

3.6

5900 to 5999

7.1

5000 to 5999

8.0

2500 to 2599

3.7

6000 to 6099

7.2

6000 to 6999

9.0

2600 to 2699

3.8

6100 to 6199

7.3

7000 to 7999

10.0

2700 to 2799

3.9

6200 to 6299

7.4

8000 to 8999

11.0

2800 to 2899

4.0

6300 to 6399

7.5

9000 to 9999

12.0

2900 to 2999

4.1

6400 to 6499

7.6

10000 to 10999

13.0

3000 to 3099

4.2

6500 to 6599

7.7

11000 to 11999

14.0

3100 to 3199

4.3

6600 to 6699

7.8

3200 to 3299

4.4

6700 to 6799

7.9

b. The 100-kHz output of Q9 in radio frequency

3300 to 3399

4.5

6800 to 6899

8.0

oscillator A6 is applied to pulse generator Q1-Q2 in

3400 to 3499

4.6

6900 to 6999

8.1

oscillator control A7. This pulse generator converts the

3500 to 3599

4.7

7000 to 7099

8.2

sinousoidal input into a 100-kHz pulse-train. The output

3600 to 3699

4.8

7100 to 7199

8.3

circuit of pulse amplifier Q3 is a parallel-resonant tuned

3700 to 3799

4.9

7200 to 7299

8.4

circuit that is selectable in 100-kHz increments between

3800 to 3899

5.0

7300 to 7399

8.5

1.8 and 0.9 MHz as shown in the following table.

3900 to 3999

5.1

7400 to 7499

8.6

Depending upon the selection made by the frequency

4000 to 4099

5.2

7500 to 7599

8.7

controls on the front panel of RT-671/PRG-47, one

4100 to 4199

5.3

7600 to 7699

8.8

single 100-kHz frequency is made available to the

4200 to 4299

5.4

7700 to 7799

8.9

subsequent circuits. A constant amplitude signal is

4300 to 4399

5.5

7800 to 7899

9.0

assured by passing this selected frequency through

4400 to 4499

5.6

7900 to 7999

9.1

4500 to 4599

5.7

8000 to 8099

9.2

4600 to 4699

5.8

8100 to 8199

9.3

4700 to 4799

5.9

3200 to 8299

9.4

4800 to 4899

6.0

8300 to 8399

9.5

4900 to 4999

6.1

3400 to 8499

9.6

5000 to 5099

6.2

8500 to 8599

9.7

5100 to 5199

6.3

3600 to 8699

9.8

5200 to 5299

6.4

3700 to 8799

9.9

5300 to 5399

6.5

3800 to 8899

10.0

5400 to 5499

6.6

3900 to 8999

10.1

2-10