---In TekScopes@..., <davidwhess@...> wrote :
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.
I was able to get a clean square wave on TP4217 with a new set of probes. I edited the post and labeled the clean waveform picture, ops. ^^ The old probe was one of those cheap twist for x1 or x10 and gave intermittent signals.
There's no difference when turning on the 20 MHz limit. I do see something that bothers me on one of the connections to the CRT. If I can capture a picture of it I'll post it.
