SILICON VERSION IF DISCRIMINATOR A4200A ALINEMENT.

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

3-19. IF DISCRIMINATOR A4200 ALINEMENT. (CONT)

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

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

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

Lift A4000 tray (1). (See test setup diagram B.)

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

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

Adjust T4206 (4) for zero-vdc reading on ME-26(*)/U.

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

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

reading occur at the same time.

SILICON VERSION IF DISCRIMINATOR A4200A ALINEMENT.

3-20.

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

separation 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

Maintenance Kit MK-1978/VRC

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