[volt-nuts] What made a HP3458A so expensive

Dr. David Kirkby drkirkby at gmail.com
Sat Jan 18 18:05:36 EST 2014

On 18 January 2014 21:15, Bill Gold <wpgold3637 at att.net> wrote:
> I did have a display that was going dim on one digit so I ordered a new VFD
> display from Agilent, not the whole board just the actual display.  When I
> compared it to the original I found that the top to bottom distance between
> the pins was larger than the original display.  So I had to carefully bend

HP / Agilent seem to have a habbit of changing parts, without changing
the part numbers. This is quite a recent experience of this for me.

1) I have a couple of HP verification kits for vector network
analyzers (85055A type-N and 85051B APC7). These consists of a couple
of airlines, a couple of attenuators, in a wooden box, with foam to
hold pieces in place. The foam degrades over time, so I ordered new
foam for two kits. While the foam fitted in the bottom of the boxes,
it was too small to fit the lid. So I had to make up my own.

2) I contact Agilent and ask if they can selll me the foam to fit the
a third verification kit I have - HP 85053B 3.5 mm. The part numbers
for the foam are still available, but I think they concluded they
would not fit my box.

3) Agilent said I could buy a new box, with the foam that fits. The
cost of this was around £350 (GBP) which seemed a bit excessive for a
small wooden box with a bit of foam inside. There was nothing wrong
with my box, so I declined.

4) Much to my delight, Agilent offer me a box free of charge to keep
good customer relations.

5) Box arrives, but the airlines from my verification kit don't fit,
as they are too long.

So basically Agilent have changed

* Size of airlines
* Design of box
* Size of foam to fit in lid of box

all without any change in part numbers!!

I've also got a 18 GHz type-N 85054B calibration kit for a VNA. The
manual on the Agilent web site, is supposed to cover the serial number
of the kit I have, yet the parts list printed on the bottom of the kit
is different to the Agilent manual. In this instance they have changed

* Part numbers of the sliding loads, although physically they look to
be similar or identical.
* Part number of the connector gages, which have changed the layout of
these a bit, so they don't fit new foam perfectly.

It does seem they can make significant changes to parts, without
giving them a new part number.


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