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Electronics => Repair => Topic started by: awesomechapro on November 26, 2024, 04:31:42 am

Title: 465B X-Y Horizontal Shift
Post by: awesomechapro on November 26, 2024, 04:31:42 am
Hi all,
I've recently been restoring an old Tektronix 465B oscilloscope. I've gotten it mostly working, but am having trouble with the X-Y mode. The normal sweep is positioned in the right spot horizontally. (in the center of the horizontal adjustment knob) But when I switch the oscilloscope into X-Y mode the dot is significantly shifted to the left. Is there an adjustment somewhere that can adjust the default horizontal position in the X-Y mode without interfering with the horizontal position of the sweep? I have already had a look throughout the service manual, the calibration procedure and the schematics to no avail.
Thanks in advance.
Title: Re: 465B X-Y Horizontal Shift
Post by: tggzzz on November 26, 2024, 09:27:22 am
What do you mean by "significantly"?

How does the issue change when you change the X-channel control settings?
Title: Re: 465B X-Y Horizontal Shift
Post by: awesomechapro on November 26, 2024, 10:26:35 am
as in when both channels a GND coupled, and the horizontal position control is at it's right most position, the dot is still to the left of the center line
Title: Re: 465B X-Y Horizontal Shift
Post by: ondraN on November 26, 2024, 01:21:47 pm
The X position can be affected by the correct setting of the trimmer R1126 "CH1 TRIG DC BALLANCE" on the CH1 preamp board. (1)