[R-390] HP 8640B Question

[2002tii]

Jerry wrote:

>True--as long as they're still working. Hard to believe they are 
>that beloved worldwide, though, since those things have been 
>dropping like flies from the same ailment for years now and nobody 
>has bothered (or paid the $) to come up with a fix for them--like a 
>new set of replacement gears. You can bet your bippy that Agilent 
>isn't the least bit interested in providing a cheap, sensible fix 
>for dying 8640B's--they'd be tickled silly if they ALL ended up in a landfill.

If they are treated carefully (proper mechanical maintenance and no 
manhandling of the controls) and not subject to temperature extremes, 
they are not so failure prone.  I assume that some nylon gears were 
made better than others (better and worse days at the gear factory), 
so some are inherently less failure prone.  Plus, HP made an enormous 
number of 8640Bs, so even large attrition leaves lots of them in service.

The problem with a fix is that since there are so many of them, 
professional/industrial users can just get a working unit from a 
reputable equipment vendor.  The broken ones go to hobbyists, who 
won't pay $200 for parts to fix them.

>I doubt spectral purity is all that critical to running an alignment 
>signal through a 50-year-old vacuum tube receiver anyway, which is 
>95% of what I do with my generators. Heck, I'm happy to just FIND a 
>signal at the other end of an RF deck or an IF strip sometimes, 
>spectrally pure or not! :)

No argument there.  For those of us who use a generator to aid in 
designing low-noise, low-distortion amplifiers and mixers, it can 
make quite a difference.

Best regards,

Don