Re: 465B..Ripple in Trace

Paul Amaranth

I'd check the ripple in the LV power supplies if you have another scope.
The test points are very easy to get at once it's out of the case.

The filter caps mostly fail open and you may have one on its way.

On Tue, Jan 18, 2011 at 05:39:14PM -0000, drbabe54 wrote:
I recently acquired a Tek 465B scope that is clean and seems to work very well except for one annoying problem.

I can see ripple (amplitude about the same as trace thickness) in both traces with vertical inputs grounded. It happens intermittently,and can be made more noticeable by fiddling with the intensity control, seems worse at mid level intensity setting. I notice it most easily with timebase set to .1 msec. I can sometimes see the same ripple when using the scope to take measurements, it is unaffected by vertical gain settings.

It doesn't appear to affect the measurements in any way but it is annoying to see it.

Should I assume it is in the HV section? Bad cap or loose ground?

I'm reluctant to tear the scope apart because it does work so well.

Any advice would be appreciated.

Paul Amaranth, GCIH | Rochester MI, USA
Aurora Group, Inc. | Security, Systems & Software
paul@... | Unix & Windows

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