The traces on my 465B scope are bright but a bit out of focus...I have
heard of resistor problems in the focus control voltage divider in
other models that have caused this same problem. I checked the CRT
schematic and noticed the resistors in question are in a resistor
network of 4 resistors.

Any thoughts on this would be helpful.
Thanks
Mike Miller
Kansas City

wrote:
The traces on my 465B scope are bright but a bit out of focus...I have
heard of resistor problems in the focus control voltage divider in
other models that have caused this same problem. I checked the CRT
schematic and noticed the resistors in question are in a resistor
network of 4 resistors.

Any thoughts on this would be helpful.
Thanks
Mike Miller
Kansas City



What's the focus control do when you adjust it?

The focus control seems to function correctly, but you can't quite get
the trace clear and sharp.

wrote in
ups.com:

The traces on my 465B scope are bright but a bit out of focus...I have
heard of resistor problems in the focus control voltage divider in
other models that have caused this same problem. I checked the CRT
schematic and noticed the resistors in question are in a resistor
network of 4 resistors.

Any thoughts on this would be helpful.
Thanks
Mike Miller
Kansas City


The thick-film resistor could be out of spec,or you could also have
astigmatism problem,or noise in the power supplies.
First,check the cathode V (-2960,IIRC)to see that it's in spec.Part of the
thickfilm network is the HV divider that sets the right voltage,part is the
focus network.(doublesided thickfilm)

465B was not known for a really sharp trace-it has a mesh lens at the end
of the electron gun structure.

--
Jim Yanik
jyanik
at
kua.net