Alignment and Calibration

Test Equipment required.

1.	Audio frequency generator, capaple of delivering at least +15dBm into 600 ohm load at 1000 Hz.
2.      A.F. Milivoltmeter, capable of measuring from, -20dBm to +20dBm at 1000 Hz. Accuracy within +/- 0.5dBm.
3	18 way extention connector, Neve partno. Z0200.

Procedure.

1.	The unit under test must be mounted free of it's rack or the console, using the 18 way extention lead, so as to
	enable access to the pre-set controls at the rear.

2.	'SET GAIN'.
	Conditions:	LIMIT			OFF
			COMPRESS		OFF
			BY=PASS			IN
			SIGNAL INPUT		0dBm, 1000Hz

	A 600 ohm termination should be used if this is the normal mode of operation, otherwise there should be no
 	termination.  Verify the input level with an appropriate range of the millivoltmeter as 0dBm indicated, then transfer
 	the millivoltmeter to the output and adjust 'SET GAIN' to achieve 0dBm indicated.

3.	'PPM IN and OUT'.

	Conditions as (2) above,

	Succesively select PPM 'IN' and 'OUT', in each case adjust the relevant pre-set potentiometer so as to achieve a
 	reading of 0dBm on the meter.

4.	'LIMIT LEVEL'.

	Conditions:	LIMIT			OFF
			COMPRESS		OFF
			BY=PASS			IN
			LIMIT RECOVERY		800mS
			LIMIT LEVEL		+8dBm
			SIGNAL INPUT		+15dBm

	Monitor the signal output with the millivoltmeter and adjust 'SET +8' to acheive a reading of +8dBm.

5.	COMPRESSION THRESHOLD.

	Conditions:	LIMIT			OFF
			COMPRESS		OFF
			BY=PASS			IN
			COMPRESSION THRESHOLD	0dBM
			RECOVERY		200mS
			PPM SWITCH		CONTROL
			GAIN MAKE UP		0

	Monitor the signal input with the millivoltmeter, and set the level to 0dBm
 	indicated.  Them adjust 'SET THRESHOLD' until just perseptable reading is seen on
 	the PPM.

	Note:  A just perceptible reading is defined as being halfway between the end stop and the first cardinal markand the meter scale.

	INTERNAL CONTROLS.

		There is only one internal pre-set control, which sets the standing collector current in the main line amplifier.
  This is set and sealed at the factory and requires no further adjustment.