Re: 7603 weirdo inverted Z axis


I checked it again and the voltage was low because the sweep was set
to 50ns/div where the beam is blanked for a significant amount of
time. At most sweep speeds, the maximum voltage was about 75 volts
and at the slowest sweep speeds where the Intensity Limit is
activated, the voltage was about 50 volts.

On 25 Jan 2016 07:39:37 -0800, you wrote:

Hi David,

From 15 V to 28 V seems a rather small change compared to the data in the calibration section. Maybe you set the time base for a slow speed that activates the Intensity Limit?


With Q1107 (a slow 2N3904???) removed on my 7603, the output at point
B is 14.8 volts which closely agrees with our current calculation so I
wonder if Marian's <public@... mailto:public@...> measurement of 20 volts at the
output of the z-axis amplifier is significant and indicates a problem.
I get the same 14.8 volt output with Q1107 installed, the readout off,
and the intensity control turned to minimum.

I also measured the output at point B and as the intensity control is
turned fully clockwise, the output increases to about 28 volts

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