Antenna Coupler CU-2229/URC-92 Checkout/Troubleshoot

TM 11-5820-873-34

Table 3-2 Checkout/Troubleshoot the Receiver-Transmitter RT-1277/URC-92-Continued

STEP

ACTION

INDICATION

NEXT STEP

137 Replace VHF Mixer CCA 1A3A1 Route original

---

VHF Mixer CCA to next higher maintenance lev-

el for repair

138 Replace Spectrum Generator CCA 1A4A1 Route

---

original Spectrum Generator CCA to next higher

maintenance level for repair

139 Replace Translator CCA 1A4A3 Route original

---

translator CCA to next higher maintenance level

for repair

140 Replace VHF VCO CCA 1A4A5 Route original

---

VHF VCO CCA to next higher maintenance level

for repair

141 Replace Low Digit Generator CCA 1A4A2 Route

---

original Low Digit Generator CCA to next higher

maintenance level for repair

142 Replace VHF Divider CCA 1A4A4 Route orig-

---

inal Low Digit Generator CCA to next higher

maintenance level for repair

143 Replace ANTENNA COUPLER CONTROL 1A2

---

Route original ANTENNA COUPLER CONTROL

to next higher maintenance level for repair

procedure The troubleshooting does not consider

3-6.

Antenna Coupler CU-2229/URC-92

incorrect or missing supply voltages to subassemblies

Checkout/Troubleshoot

Before any replace/repair action is accomplished on a

The following procedures in Table 3-3 will establish the

subassembly, the test technician should verify all

operational readiness of CU-2229/URC-92 antenna

necessary supply voltages at the subassembly Refer to

coupler. Successful completion of the checkout portion

List of Illustrations for appropriate schematics Incorrect or

indicates the antenna coupler is operationally ready for

missing supply voltages are not authorized for repair at

use. Troubleshooting procedures are designed to function

this maintenance level If supply voltage malfunctions are

from incorrect Indications in the checkout Following any

noted, route the Antenna Coupler CU-2229/URC-92 to the

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

next higher maintenance level for repair.

the checkout unless instructed differently by the

Table 3-3. Checkout/Troubleshoot the Antenna Coupler CU-2229/URC-92

STEP

ACTION

INDICATION

NEXT STEP

Remove case from Antenna Coupler

Step 2a

CU-22291URC-92 Connect RF and control

cables between the Antenna Coupler to be

checked and a known good RT-1277/URC-92

Receiver-Transmitter. Insure the receiver-trans-

mitter is correctly powered and grounded

Set mode switch to AM.

COUPLER STATUS FAULT indicator illumi-

Yes: step 2b

nates.

No: step 7

Disconnect RF cable at the receiver-transmitter

Connect a 50 ohm dummy load to the receiver-

transmitter.

NOTE

A means of timing, in seconds, is required for this

step.

Set mode switch to CPLR TUNE KW. Depress

COUPLER STATUS FAULT indicator goes out

Yes: step 3a

TUNE START. Begin timing and observe

COUPLER STATUS TUNING indicator is Illumi-

No: step 8

COUPLER STATUS indicators.

nated and transmitter keys on. After 35 to 45 se-

conds, transmitter unkeys and COUPLER

STATUS TUNING indicator goes out COUPLER

STATUS FAULT indicator illuminates

Disconnect dummy load from receiver-

COUPLER STATUS TUNING indicator il-

Yes: step 3b

transmitter. Reconnect rf cable from Antenna

luminates, transmitter keys and both drive

No: step14

Coupler. Connect 50 ohm dummy load to the

motors, 2M1 and 2M2, drive.

Antenna Coupler antenna post. Connect ground

3-12