Antenna Coupler CU-2229/URC-92 Adjustments

TM 11-5820-873-34

e. VHF Mixer CCA 1A3AI Adjustments.

Sideband Generator CCA 1A3A3. Rotate XMIT GAIN

(1) Remove receiver-transmitter top cover

control fully counterclockwise Set mode switch to USB.

Remove Receiver/Exciter protective cover. Place VHF

(d) Alternately adjust 1A3A3R34 and

Mixer CCA on card extender.

Connect RF signal

1A3A3C26 for minimum output reading on VTVM.

generator to ANT jack 1A8J1 Set RF signal generator to

(3) ALC Adjustment Set front panel frequency

16 MHz.

switches to 16 MHz. Set mode switch to CW. Key

(2) Set front panel frequency switches to 16 MHz.

transmitter and adjust 1A3A3R55 for 71 volts RMS output

Set mode switch to USB Adjust front panel RF GAIN

on VTVM.

control for an S9 reading on the ANTENNA COUPLER

(4) ACC Adjustment Set mode switch to AM.

CONTROL S meter 1A2M1.

Adjust 1A3A3R18 for 42 volts RMS output on VTVM.

(3) Set RF signal generator level to 10 mV and

(5) Remove card extender and reinstall Sideband

adjust signal generator frequency until a tone is heard

Generator CCA 1A3A3.

Reinstall Receiver/Exciter

from the receiver speaker.

protective cover. Reinstall receiver-transmitter top cover.

(4) Alternately adjust 1A3A1C41 and C44 for a

Remove dummy load.

maximum peak on S meter 1A2M1.

4-19. Antenna Coupler CU-2229/URC-92 Adjustments

(5) Alternately adjust 1A3AlT7 and T8 for a

maximum peak on S meter 1A2M1.

The following adjustments are not intended as a means of

(6) Readjust 1A3A1T7 and 1A3A1C44 for

checkout or troubleshooting. If an adjustment cannot be

maximum S meter, 1A2M1, peak.

performed,

troubleshoot

using

conventional

(7) Remove card extender and install VHF Mixer

troubleshooting methods. Refer to List of Illustrations for

CCA 1A3A1 Reinstall Receiver/Exciter protective cover.

required schematic figure numbers.

Reinstall receiver-transmitter top cover.

a. C MAX/C MIN Limit Switch Adjustments (Fig 4-18)

f. IF/Filter CCA 1A3A2Adjustment.

(1) Remove case from Antenna Coupler CU-

(1) Remove receiver-transmitter top cover

2229/URC-92. Remove Phase and Amplitude Control

Remove Receiver/Exciter protective cover.

Place

CCA 2A2. Remove 2M1/2C1 drive belt (2).

IF/Filter CCA on card extender Connect RF signal

(2) Connect multimeter between 2XA2-11 and

generator to ANT jack 1A8J1. Set RF signal generator to

chassis ground.

Rotate capacitor shaft (3)

16 MHz.

counterclockwise (viewed from pulley end) until shaft just

(2) Set front panel frequency switches to 16 MHz.

begins to leave capacitor end plate.

Set mode switch to USB. Adjust front panel RF GAIN

NOTE

control for an S9 reading on the ANTENNA COUPLER

Shaft will rotate more freely at the point

CONTROL S meter 1A2M1.

where it begins to leave the capacitor end

(3) Set RF signal generator level to 10 mV and

plate

adjust signal generator frequency until a tone is heard

Rotate shaft (3) clockwise (viewed from pulley end) two

from the receiver speaker.

complete turns

(4) Alternately adjust 1A3A2L3 and L4 for a

(3) Adjust C MAX plunger (1) to activate C MAX

maximum peak on S meter 1A2M1.

2S4 (meter indicates short) at this shaft position.

(5) Remove card extender and reinstall IF/Filter

(4) Connect multimeter between 2XA2-8 and

CCA 1A3A2. Reinstall Receiver/Exciter protective cover.

chassis ground. Rotate shaft (3) clockwise (viewed from

Reinstall receiver-transmitter top cover.

pulley end) 15 complete turns.

g. Sideband Generator CCA 1A3A3 Adjustment.

(5) Adjust C MIN plunger (4) to activate C MIN

(1) Remove receiver-transmitter top cover

2S3 (meter indicates short) at this shaft position.

Remove Receiver/Exciter protective cover. Place Side-

(6) Disconnect multimeter and reinstall 2M1/2C1

band Generator CCA 1A3A3 on card extender. Connect

drive belt. Reinstall Phase and Amplitude Control CCA

a 50 ohm dummy load to ANT jack 1A8J1. Connect

2A2. Reinstall antenna coupler in case.

VTVM (AC) across the dummy load.

b. L MAX and L MIN Limit Switch Adjustments.

(2) Balanced Modulator Tuning.

(Fig 4-19)

(a) Rotate 1A3A3R34 fully counterclockwise.

(1) Remove case from Antenna Coupler CU-

Then turn 1A3A3R34 approximately 8 turns clockwise Set

2229/URC-92.

front panel XMT GAIN fully counterclockwise. Set mode

(2) Connect multimeter between L MAX plunger.

switch to USB.

(3) and chassis ground Rotate inductor to move

(b) Using microphone, key transmitter and

roller (2) in contact with L MAX plunger. Stop when

observe VTVM. With transmitter keyed, adjust 1A3A3T1

roller/plunger contact causes meter to indicate a short.

for maximum output reading on VTVM.

(3) Check the distance from the roller to the end

4-44