[ARC5] manual for a hp 428

[Dennis Monticelli]

The magnetometer accessory probe is extremely rare.  They sold very few.
They sold lots of regular probe 428's.

I forgot that HP added the scope output in going from the A to the B.  The
feedback loop (with 400Hz BW) was already there so all they had to do was
bring the signal out.  Incidentally, the feedback loop in the FW Bell solid
state version is good to 2KHz so it can be used for audio current readings.

Dennis AE6C

On Mon, Aug 23, 2010 at 9:10 PM, Roy Morgan <k1lky at earthlink.net> wrote:

>
> On Aug 23, 2010, at 7:06 PM, james aschenbach wrote:
>
> >
> > can any one tell me where I can get a down load manual for a HP 428
> > current meter
>
> The issue of the HP Journal that describes the 428B is at:
> www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1961-11.pdf
> This article tells the differences between the A and B model (A: 3ma
> to 1 amp, B: 1 ma to 10 amps. and the B has low frequency AC scope
> output ).
>
> a later article on a new probe for sensing magnetic fields with the
> instrument can be found at:
> www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1963-03.pdf
>
> Roy
>
> Roy Morgan
> k1lky at earthlink.net
> K1LKY Since 1958 - Keep 'em Glowing!
>
>
>
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