[Test-Equipment] HP 8640B Fuse Question

[Richard Knoppow]

On 2/4/2015 11:21 AM, Barry wrote:
> Update:
>
> I placed a 2A fuse in series with my ammeter across the fuse test points and the regulator board came alive.  The fan started working and the generator is putting out a signal (modulation works, attenuator works, controls are a bit sensitive, etc.).
>
> Ammeter reads about 1.55A so it it made sense why the 1.5A fuse blew.  I wonder if it coasted along at something just under 1.5A and as various components aged and the line voltage went up in general, it finally blew.
>
> Someone put a sticker on the inside that reads "KAPUT".  Sure was a pretty easy fix for someone to give up on it.  Probably was not someone's personal generator and they had no big reason to fix it.  Don't know.
>
> The counter isn't reflecting the generated frequency ("000100" or something like that) so I have some work to do there, but at least most parts are proven to work.
>
> Thanks for listening,
> Barry - N4BUQ
>
>        Doesn't the handbook state the correct fuse size?  Usually line fuses are set to be about 1.5X to double the normal current to prevent blowing from inrush.  If a fuse of specified size blows there is a problem.  The counter not working properly may be a clue.  Check the power supplies carefully, it might point to a bad capacitor somewhere.

-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL