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Figure 3 TP5 ACC (magnified picture near adjustment trimmer)
2.1.2. Measurement and adjustment
Carry out measurement and adjustment according to below sequence.
● assemble a measurement system according to block diagram (figure 1).
*CAUTION: There is no switch, and power is turned on when connect an
AC adaptor and the power JACK.
● Input sin wave (440Hz, -40dBm) to the INPUT JACK (J200).
● Measure a level of TP5 ACC, and adjust the VR700 for fitting into range
of provided level.
● Measure a level of the measure point on the jig, and adjust the VR702 for
fitting into range of provided level.
● Change a tube if that level doesn’t fit into range of provided level, and
adjust again.
Provided levels are
[1]. [TP5 ACC: -17.0 dBm ± 1.5dBm]
[2]. [Measure point on the jig: -20.5dBm ± 1.5dBm]
Both levels can be changed by adjusting VR700. Therefore, if only level of [2]
doesn’t fit into range of provided level, make this level fit into the range by adjusting
the VR700. As long as level of [1] isn’t in out of the range.
*CAUTION: Each tubes have different characteristics, and this adjustment necessary
to adjust for matching tube with PCB. Therefore adjusted tube and
PCB must be handled in a pair.
TP5 ACC
VR700 VR702
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