Chapter 3. DIRECT SUPPORT

TM 11-5820-873-34

CHAPTER 3

DIRECT SUPPORT

Section I. GENERAL

3-1. Scope

checkout/troubleshoot for the antenna coupler CU-

This chapter contains checkout, troubleshooting, repair,

2229/URC-92.

removal, replacement and other maintenance

authorized for direct support of Radio Set AN/URC-92.

3-2. Voltage Measurements

The checkout and troubleshooting procedures are

separated into a checkout/troubleshoot for the receiver

Applicable voltages and acceptable tolerances are listed

transmitter

RT-1277/URC-92

and

in Table 3-1

Section II. TOOLS AND EQUIPMENT

3-3. Test Equipment

Table3-1 Voltage Measurements

0VDC 0.2

12 VDC 0.8

Refer to TM 11-5820-873-12, Appendix D, TM

2VDC 0.5

22 VDC 1.5

11-5820-873-20P and TM 11-5820-873-34P Also,

3VDC 025

28 VDC 1.5

a BNC to clip lead cable is required (Fig 3 -1)

5 VDC 0.25

7.7VDC 08

9VDC 0.8

12VAC 0.8

9.56VDC 0.8

20VAC 1.5

10 VDC 0.8

115 VAC 15

Figure 3-1 BNC/Clip Lead Cable.

Section III. CHECKOUT/TROUBLESHOOT

The procedures correspond with the authorized

3-4. General

maintenance level at direct support. Following any

This section contains checkout and troubleshooting for

repair action, the test technician must return to step 1 of

both the receiver-transmitter and the antenna coupler.

the checkout unless directed differently by the

Completion of a checkout signifies a particular unit is

procedure.

The troubleshooting does not consider

operationally ready for use. Troubleshooting procedures

incorrect or missing supply voltages to subassemblies.

are designed to function from incorrect indications in the

Before any replace/repair action is accomplished on a

checkout.

subassembly, the test technician should verify all

3-5. Receiver-Transmitter RT-1277/

necessary supply voltages at the subassembly. Refer to

URC-92 Checkout/Troubleshoot

List of Illustrations for the appropriate schematic.

Incorrect or missing supply voltages are not authorized

The following procedures in Table 3-2 will establish the

for repair at this maintenance level. If supply voltage

operational readiness of RT-1277/URC-92 receiver-

malfunctions are noted, route the Receiver-Transmitter

transmitter. Successful completion of the checkout

RT-1277/URC-92 to the next higher maintenance level

portion indicates the receiver-transmitter Is operationally

for repair.

ready for use. Troubleshooting procedures are designed

to function from incorrect indications in the checkout.

3-1