SILICON VERSION IF DISCRIMINATOR A4200A ALINEMENT.

TM 11-5820-401-34-3/0967-LP-432-3060

5-19. IF DISCRIMINATOR A4200 ALINEMENT. (CONT)

1. Turn AN/URM-103 DEVIATION control clockwise until DEVIATION KHZ meter reads 8 kHz.

2. Set ME-26(*)/U to 1-vdc scale and turn ZERO ADJ for midscale reading.

3. Set ME-30(*)/U to 3-volt scale.

4. Lift A4000 tray (1). (See test set up diagram

5. Connect ME-26(*)/U positive lead to TP4003 (2), and negative lead to ground.

6. Connect ME-30(*)/U positive lead to TP4007 (3), and negative lead to ground.

7. Adjust T4206 (4) for zero-vdc reading (center of scale; no deflection) on ME-26(*)/U.

8. Adjust T4207 (5) for peak reading ME-30(*)/U.

9. Repeat steps 7 and 8 until maximum ME-30(*)/U reading and zero-vdc ME-26(*)/U reading

occur at the same time.

5-20. SILICON VERSION IF DISCRIMINATOR A4200A ALINEMENT.

PURPOSE. This procedure enables the integrated circuit discriminator to provide maximum separa-

tion of the audio signal from the rf carrier. Coil L4202 is adjusted to tune the fm detector portion of the

integrated circuit exactly to the 11.5-MHz center frequency.

TEST EQUIPMENT AND MATERIALS

Matching Unit CN-901/U

Signal Generator AN/URM-103

T-Connector UG-274/U

Frequency Counter AN/USM-207

Loudspeaker LS-454/U

Power Supply PP-1104(*)/G

Voltmeter ME-30(*)/U

Test Cable No. 1

TEST SETUP. Connect the equipment as shown in test setup diagram

442/VRC bottom cover. (See paragraph 2-7.)

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