[volt-nuts] 3458A reference boards on ebay

[Dr. David Kirkby (Kirkby Microwave Ltd)]

On 27 Jan 2015 09:47, "Orin Eman" <orin.eman at gmail.com> wrote:
>
> There is a seller letting a slow trickle of them out there... they seem to
> be going for about $165.  The current batch of two is around $100, but
will
> probably be bid up.

I am puzzled why there are so many reference boards that are supposed to
come from 3458As on the used market. It makes me wonder if they are
genuine.

One seller,  with the two high stability reference boards at $750, claims
that they come from working and recently calibrated 3458As. Why would
anyone wreck a working and recently calibrated 3458A?

It is not beyond the bounds of possibility that a 3458A might be worth more
in parts than as a complete unit. I know this is true for some HP items,
but I doubt that is the case with a 3458A.

Another seller,  who has them at $395 "or offer", has sold 17 and has 11
left.

Although expensive,  having two and monitoring the difference between them
would probably allow their stability to be measured with a DVM of modest
specification.

There are lots of counterfeit components around,  and I fear that it could
be some of these boards could fall into that category.  This makes the
building a board from new components more attractive.  In the short term it
is likely to be less stable than an old reference,  but at least one would
know the history of it. If the components were sourced from reliable
sources, it would get around the  potential counterfeit problem.

Dave.