ANTENNA TUNER A2A2 ALIGNMENT

TM 11-5820-919-40-2

ANTENNA TUNER A2A2 ALIGNMENT

The alignment procedure is to be used in either of these situations: (1) the performance test calls a potentiometer out of adjustment, or (2) one of the following is

replaced:

Comparator/Control Hybrid A1

RF Sensor Bridge

The procedure consists of a preliminary setup and adjustment procedure. The adjustment procedure can be shortened by adjusting R1, R2, B3 and R4 to the values

given in step 13 below. The complete procedure need only be run if work has been done on the rf Sensor Bridge.

PRELIMINARY SETUP

ADJUSTMENT

ADJUSTMENT (cont)

1. Connect test radio as in figure 10-5.

1. Close CW KEY and switch MODE to V-RCV and

10. Adjust B3 until the 1.5 vswr reference voltage,

back to V-TR. This generates a tune start pulse.

TP9, is the same as that noted in step 9.

2. Connect an rf signal generator to the input of the

power amplifier module at A1J1. Set the level to

2. Ground (continuously) E7 of ribbon cable.

11. Adjust B2 until the 1.6 vswr reference voltage at

-100dbm and the frequency to 2.000 MHz.

TP8 is +10.6v higher than that of TP9.

3. Increase level of rf signal generator until TP13 is

3. Remove the antenna tuner module from the test

+10v rms. This corresponds to 2 watts in a 50-ohm

12. Adjust B1 until the voltage at TP7 is +3.0v.

bed radio. Separate the two halves of the antenna

system.

tuner module which is to be aligned, except for the

13. The following are typical settings after alignment:

interconnecting ribbon cable.

4. Measure the dc output of the Z sensor at TP12.

Record voltage at TP12.

ALC REM

TP7

+3.0v

4. Plug the antenna tuner module to be aligned into

1.6 REP

TP8

+4.3v

the test bed radio.

5. Adjust R4 until the Z comparator reference

1.5 REP

TP9

+3.7v

voltage, TP10, is the same as that measured in step

ZREF

TP10

+3.3v

5. Connect the 100 ohm load (figure 3-11E, TM 11-

5820-919-40-1 to the radio set BNC connector.

14. Turn radio off and disconnect test equipment.

6. Replace the 100 load with the 130-ohm load (figure

Reassemble the two boards of the antenna tuner

6. Set the radio control to the following:

3-11-F, TM 11-5820-919-40-1).

module being very careful to avoid pinching the ribbon

cable.

FREQUENCY KHz to 02,000.0

7. Adjust the rf signal generator so that the voltage at

MODE to V-TR

TP13 varies between +7 ant +14v (+7v = 1 watt, +14v

SB to USB

= 4 watts) and measure the output of the vswr

VOLUME to on

detector at TP11. But, do not stay at the 4-watt level

ANT SEL to BNC

for any length of tine.

8. Adjust the level compensation resistor, R7, for

minimum variation in do output of TP11 as performed

in step 7.

9. Once R7 is adjusted, adjust the rf signal generator

so that TP13 is +10v rms, Note the voltage at TP11.