Figure 2-15.Indicator assembly.

INDICATOR

working with transistors and that they follow the

instructions in the proper technical manual. The

manufacturer has specified the use of certain meters

The crosswind component signals are applied to

for analyzing the condition of the components of the

the crosswind indicator of the indicator assembly

unit, and, where possible, these should be used.

(shown in fig. 2-15). The headwind component signal

is applied to the other indicator in the assembly. The

SYNCHRO SIGNAL CONVERTER AND

indicators have microammeter movements. The

SYNCHRO SIGNAL ISOLATION

headwind indicator is calibrated for 50 microampere

AMPLIFIER

full-scale deflection, which corresponds to 60 knots.

The dial reads from 0 to 60 knots in 1-knot

Another of the recent developments in the use of

increments. The crosswind indicator is calibrated for

synchro signals is in the synchro signal converter and

25 microampere for full-scale deflection left and

synchro signal isolation amplifier shown in figure 2-

right. The crosswind scale reads from 30 knots port to

16.

30 knots starboard in 1-knot increments. The

rheostat on the assembly connects in series with the

The problem of retransmitting accurate wind

secondary of the line transformer and the

information devoid of error and unwanted feedback to

illuminating lamps, and is used to control their

the transmitter has existed for some time. The

intensity.

additional problem of conversion of a 60-Hz signal for

MAINTENANCE AND

use in computers is also not new. The synchro signal

TROUBLESHOOTING

isolation amplifier receives its signal from the wind

system and prepares it for the converter, allowing the

exact signal to be converted to 400 Hz.

The maintenance of this unit is outlined in the

appropriate PMS documents. The technical manual

ISOLATION AMPLIFIER

for

the

equipment

contains

adequate

troubleshooting chart. Therefore, there should be no

The amplifier contains two chassis that are the

difficulty in keeping the unit running. You should be

same, one for direction and one for speed. The

sure that personnel trying to repair the amplifier

principles of

units are familiar with the proper techniques for

40.135

Figure 2-15.Indicator assembly.

2-16