JVC KV-V8 service manual Standard tracking preset, Tension pole position

[Perform adjustment steps (7) to (10) only for 2 Head models equipped with LP mode.]

(7)Then play back the alignment tape (A2).

(8)Set the VCR to the manual tracking mode.

(9)Perform the tracking operation and make sure that the V.PB FM waveform is at its maximum.

(10)If it is not at maximum, loosen the screws (4) and (5), and turn the A/C head positioning tool to bring the A/C head to a position, around where the waveform reaches its maximum for the first time. Then tighten the screws

(4) and (5).

Note:

•After adjusting, always perform the confirmation and re-adjustment of the item 2.5.4.

A/C head			(5)
positioning tool
	A/C head
	(5)		(4)
		To the capstan
		(4)
To the drum
		Fig. 2-5-3a
		Alignment tape	Alignment tape
		[SP, stairstep]	[EP(LP), stairstep]
		played with the	played with the
output		SP head	EP(LP) head
Waveform
		X-value adjustment point
Drum side	Control head position		Capstan side
			Maximum
		Fig. 2-5-3b
2.5.4 Standard tracking preset
		[KV-V8E]
Signal	(A)	• Alignment tape(LP, stairstep, PAL) [MHPE-L]
		- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
		[KV-V8J]
	(A)	• Alignment tape(EP, stairstep, NTSC) [MHP-L]
Mode	(B)	• PB ¥ Auto adjust
Equipment	(C)	• Oscilloscope
Measuring point	(D)	• TP106 (PB FM)
External trigger	(E)	• TP111 (D.FF)
Adjustment part	(F)	• Jig RCU: Code “50”
Specified value	(G)	• STOP mode
		(Maximum V.PB FM waveform)
Adjustment tool	(H)	• Jig RCU [PTU94023B]

(1)Play back the alignment tape (A).

(2)Apply the external trigger signal to D.FF (E), to observe the V.PB FM waveform at the measuring point (D).

(3)Confirm that the automatic tracking operation is com- pleted.

(4)Set the VCR to the Auto adjust mode by transmitting the code (F) twice from the Jig RCU. When the VCR enters the stop mode, the adjustment is completed.

(5)If the VCR enters the eject mode, perform adjustment for the A/C head phase (X-value) again.

2.5.5 Tension pole position

Signal	(A)	• Back tension cassette gauge
		[PUJ48076-2]
Mode	(B)	• PB
Adjustment part	(F)	• Adjust pin [Mechansim assembly]
Specified value	(G)	• 29 - 46 gf•cm (2.84 – 4.5 ⋅ 10-3Nm)

(1)Play back the back tension cassette gauge (A).

(2)Check that the indicated value on the left side gauge is within the specified value (G).

(3)If the indicated value is not within the specified value (G), perform the adjustment in a following procedure.

1)Set the VCR to the mechanism service mode. (See 1.5 Mechanism service mode.)

2)Set the VCR to the play back mode and turn the ad- just pin using the flat-blade screwdriver, etc. by pay- ing attention not to come into contact with the 2.5 mm dia. pole. (See Fig. 2-5-5a.)

2.5 pole Adjust pin

Tension arm assembly

Fig. 2-5-5a

2-14