SYNTHESIZER A1A3 ALIGNMENT

TM 11-5820-919-40-2

The alignment procedure is to be used whenever TCXO U1, VCO U3, or 1lmlter

U7 is replaced or whenever the first LO, second LO, or TCXO output frequency

or power is out of alignment. The procedure consists of preliminary setup and

adjustment.

ADJUSTMENT

PRELIMINARY SETUP

1. Monitor TP15 filth DVM. If required, remove turns from T3 winding

1. Remove the synthesizer from the receiver /exciter and connect the

1-2 (red wire) until DVM reads +3.1 0.4v.

module as in figure 5-2.

2. Set dc power supply (7 amp) to +26.5v.

2. Adjust R21 so that A3J3 is at the frequency stenciled on TCXO U1

3. Connect the tracking generator (used as a counter) to A3J3 via rf coax

case 0 5 Hz.

cable.

3. Disconnect rf extender cable from A3J2. Disconnect rf coax cable.

4. Set VOLUME switch on control panel to on.

Connect the watt meter to A3J2 via rf coax cable.

5. Set SB switch on control panel to USB.

4. Adjust R4 of limiter U7 until wattmeter reads -4.0 0.1 dbm.

6. Set FREQUENCY KHZ switches on control panel to 29,990.0.

5. Set SB switch on control panel to LSB.

6. Adjust R10 of limiter U7 until wattmeter reads -4.0 0.1 dbm.

7. Disconnect of extender cable from A3J1. Disconnect rf coax cable

from A3J2 and connect to A3J1. Reconnect rf extender cable (step 3)

to A3J2.

8. Adjust R19 of VCO U3 until wattmeter reads +3.0 0.1 dbm.

Disconnect the test equipment.