TEST SET OPERATION. (CONT) - TM-11-6625-2975-120021

TM 11-6625-2975-12

1-13. TEST SET OPERATION. (CONT)

SIGNAL

OUTPUT PARAMETER

CHARACTERISTIC

VOR rf carrier frequency

Selected standard VOR ground station frequency.

30 Hz variable AM/9960 Hz FM (30 Hz reference)

Rf carrier modulation

composite audio signal.

30.0 percent.

Amplitude (%) modulation

000.00 degree.

VOR radial

TO or FROM status indicator

FROM.

-50 db mW. (If the output level is changed after

Output level

initial power on or after self-test, the level

remains at the selected level.)

The rf carrier frequency is variable to greater than 0.025 percent of selected frequency to check

receiver selectivity. The carrier frequency can be varied in either direction at a fast or slow rate

depending on test requirements.

The rf output level is adjustable from -6 to -120 db mW to allow operator selection of output level

required to meet test requirements for receiver response. The output level can be increased or

decreased in either 1 or 10 db steps as required by the operator.

Amplitude (%) modulation of simulated VOR signal is adjustable from 10.0 to 35.0 percent in

O.1-percent increments to check receiver response.

TO/FROM indication is determined by phase relationship of composite audio VOR signal and is always

a FROM signal on initial selection of VOR mode. Through keyboard entry, the FROM signal can be

changed to a TO signal, which phase shifts VOR bearing signal by 160 degrees.

A 1020 Hz audio tone to test the receiver audio circuits can be added to VOR rf output signal at 30-

percent modulation by keyboard entry. Individual control of identification signal allows operator to

add or remove the signal as required during receiver checks.

Either or both of the 30 Hz variable or 9960 Hz FM signals can be removed as required to perform

receiver flag checks.

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