Calibration of T-1054(P)A/GRC-144(V) Reflected RF Power Metering Circuit

TM 11-5820-695-35

Remove Dummy Load, Electrical DA-641/

Remove Dummy Load, Electrical DA-

41/ GRC from Adapter, Waveguide UG-1883/GRC and

GRC from Adapter, Waveguide UG-1883/GRC and

connect the test equipment in figure 3-29.

connect the test equipment as shown in figure 3-29.

Adjust the PUSH TO TURN control on

Adjust the PUSH TO TURN control on radio

frequency bandpass filter 1FL3 until a null is obtained on

radio frequency bandpass filter 1FL3 until a null is

AN/USM-161 NULL INDICATOR meter.

obtained on AN/USM-161 NULL INDICATOR meter.

Set Switch, Waveguide SA-1679/GRC to

Turn the meter selector switch

the TO ANT. (NORMAL) position.

1A15A8S4 on meter panel assembly 1A15A8 to RF

POWER.

Turn the AN/USM-161 off and disconnect

Remove the protective plate over the

cable assembly CG-2514/U from Adapter, Waveguide

UG-1883/GRC.

potentiometer bracket and adjust potentiometer

1A15A8R6, figure 34. If a meter indication-of 60 cannot

Connect the 3 db attenuator and type N

be obtained, refer to the troubleshooting chart (item No.

short (fig. 3-29) to Adapter, Waveguide UG-1883/GRC.

69, para 386b) for corrective action upon completion of

Set Switch, Waveguide SA-1679/GRC to

this procedure.

the TO LOAD (TEST) position.

Reset the controls on radio frequency

Turn meter selector switch 1A15A8S4 on

bandpass filter 1FL3 and electrical frequency

meter panel assembly 1A15A8 to REFL RF POWER.

synthesizer 1A14 to the original operating frequency

recorded in step f.

Remove the protective plate over the

potentiometer bracket and adjust potentiometer

Set

Switch,

Waveguide

SA-

1A15A8R5 (fig. 3-4) for a 1A15A8M1 meter indication

1679/GRC to the TO ANT. (NORM-AL) position.

of 20. If a meter indication of 20 cannot be obtained,

Connect Dummy Load, Electrical DA-

refer to the troubleshooting chart (item No. 40, para 3-

541/ GRC to Adapter, Waveguide UG-1883/GRC.

6b) for corrective action upon completion of this

procedure.

Turn off the

AN/USM-161

and

disconnect the test equipment.

Set the controls on electrical frequency

synthesizer 1A14 and radio frequency bandpass filter

3-58. Calibration

T-1054(P)A/GRC-144(V)

1FL3 to the original operating frequency recorded in

Reflected RF Power Metering Circuit

step f.

Turn on Test Set, Radio Frequency Power

Set Switch, Waveguide SA-1679/GRC to

AN/USM-161 and allow a 30-minute warmup period.

the TO ANT. (NORMAL) position.

Calculate the calibration plate correction

Disconnect the 3 db attenuator and type N

factors of the two CN-845/USM-161's and the CG-

short from Adapter, Waveguide UG-1883/GRC.

2514/U (fig. 3-29) for a 4800 MHz input. Algebraically

add the correction factors noting the plus or minus sign

Connect Dummy Load, Electrical DA-541/

and record.

GRC to Adapter, Waveguide UG-1883/GRC.

Calibrate the AN-/USM-161

using

the

3-59. Calibration of T-1054(P)/GRC-144(V) and T-

procedures given in TM 11-6625-498-12.

1054(P)A/GRC-144CV) Frequency Multiplier Metering

On the AN/USM-161, set the BIAS-READ

Circuits.

switch to READ, turn the POWER RANGE switch to 3.0

NOTE

MW +6 DPM, set the COMP ATTENUATOR dial to the

Do not calibrate any of the T-1054(P)/

value recorded in step b above, and set the POWER

GRC-144(V)

frequency

multiplier

indicator dial for a dial scale indication of 1.6 on the

metering circuits when the T-

center scale.

1054(P)/GRC-144(V) output power is

Set Switch, Waveguide SA-16789/GRC to

less than 150 milliwatts. If the output

the TO LOAD (TEST) position.

power level is not known, use the T-

Record the T-1054/GRC-144 operating

1054(P)/GRC-144(V) output power

frequency and then set the controls on electrical

test (para 3-72) to determine it.

frequency synthesizer 1A14 to 4800.0 MHz.

To calibrate any of the T-1054/GRC-144 frequency

If the RF POWER indicator on meter panel

multiplier metering circuits, turn meter selector switch

assembly 1A15A8 is not lighted red, adjust the PUSH

1A15A8S4 (fig. 3-4) to the circuit to be calibrated and

TO TURN knob on radio frequency bandpass filter 1FL3

observe the indication on meter 1A15A8M1. If meter

until it lights red.

indication is not 100, remove the protective plate over

the potentiometer

Change 6

3-77