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WTB Tektronix 564

In "Oscilloscopes Selecting and Restoring a Classic" (1992) by Stan Griffiths, W7NI, the 564 is not recommended due to the short life span of the special "storage" CRT:

Quote:

Buy a storage oscilloscope only if you really need the storage feature. They cost more to maintain and replacement cathode ray tubes can be impossible to find

The same book shows the 561A, which is the same size and takes the same plug-ins:

Quote:

the 561A is a good general purpose mainframe. You will need two plug-ins to make it a complete oscilloscope.

Of course, you could get lucky and find a 564 with a good tube.

jr

Quote:

Originally Posted by andy (Post 3034498)

I agree that mesh storage isn't a very useful feature anymore, but if I'm going to make room for a vintage scope, I might as well get one with everything.

The 564 is not a mesh storage scope... the storage takes place on the P-1 phosphor surface itself, and the stored information is "illuminated" by low voltage electrons. In order to get usable brightness of the stored traces, at these low voltages, a fairly high current density is used. This will cause "aging" (loss of efficiency) of the phosphor areas most used for storage of traces.
This is similar to the aging observed in a 6E5 indicator "eye" for many of the same reasons... P-1 phosphor bombarded with high current (low voltage) electrons yields loss of phosphor efficiency in the most used areas. I have seen several used 564s with ugly dark areas/traces "burned" into the phosphor, seen in "store" mode...."non-store" operation is usually not degraded by these "burned" areas.

IMHO, the 564 is a lot more fun than a 561... if you get one with a good CRT, and don't use the storage function too much, it can last for many years.

jr