[R-390] HP-410B Question

[Randy and Sherry Guttery]

On 2/19/2011 7:42 PM, Barry wrote:
> I have an HP-410B that I'm restoring.  It has a small value cap (5000pf or so) across the meter but it also has a 50uF cap across the meter as well.  I've been advised to just remove that 50uF cap as it isn't really needed (it's not on some of the newer models).
Disclaimer - *I* don't know - just passing on what someone 
else told me (who happened to be a design engineer at HP at 
the time) -

When I asked why two caps - he noted that the smaller cap was to bypass any RF that might leak into the meter movement from the front - since the shielding wasn't all that good there... and the larger one was to slow down the response so the pointer and the rest of the works didn't "slam" off the stops so hard on an overload...

He too noted that the larger caps had been left out of later 
production units.

best regards...

-- 
randy guttery

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