It does look like there is something wrong with the focus. Vertical
blurring could be caused by wide bandwidth noise since it is a 100 MHz
oscilloscope but the horizontal blurring matches it so something else
is going on.
Your measurement of TP4217 does not look correct at all. It needs to
be made with a x10 probe to preserve bandwidth and should look like a
clean square wave.
As far as noise from the vertical amplifier, turning on the 20 MHz
bandwidth limit will lower the noise level. You can also disconnect
the CRT leads from the vertical amplifier but be careful not to damage
the CRT.
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On 28 Mar 2016 07:03:31 -0700, you wrote:
Hello I was told this is the place to be for asking questions about Tektronix scopes.
I rescued a 465B from ebay that showed no trace. When it arrived I was able to get a trace to show just by adjusting the controls. The only issues I can see are a thick trace and a sensitive intensity knob. Although, Having messed with the scope for a few weeks I think the intensity works as it should. Being my first Tektronix scope I started a post on the EEV blog hoping to find more info on repairing it. The kind folks over on the EEV suggested I join the TekScopes group. I am very impressed with this group and how active it is!
Currently I'm starting to suspect the CRT is faulty on this scope.
I have tested the power supply for voltage and ripple. Found a beautiful triplett 630-na to test the high voltage. The tek manual recommended it and I thought it was a great excuse... I mean... a good idea to use the recommended equipment. ;) The HV tested spot on. Tested focus voltage and it seems ok. I also checked all the other lv connections to the CRT for voltage and noise. I also probed the horizontal and for noise.
How can I eliminate the vertical section as the fault? Is it safe to just disconnect the vertical connections?
Also I did read somewhere in the TekScopes group about shorting the vertical connections with a capacitor but I could not find anymore info on that.
I'm just a self taught hobbyist and I've been taking my time. ^-^
EEV post Tektronix 465B Focus Issue - Page 1
David Hess