For anyone interested, the problem was indeed the jig. There is a "50
Ohm Follower" board that is built into the mainframe, and that is the
primary difference between the 067-0655-00 and the 067-0589-00. We
bypassed the jig by purchasing a used mainframe and pulling the coax
signal lines to the outside of the scope body. It's sad to scrap a
scope like that, but the jig cost ~$3000.00, and a used mainframe is
$300 and has two voltage follower boards. Hope this helps someone,
but I have a feeling there's not a whole lot of 7000 series mainframe
calibration going on anymore.

Steve

On Aug 30, 7:56*am, sck0006 wrote:
We're running through the calibration on our 067-0587-10 Standardizers
and they're failing frequency response. *All points lead to the
067-0655-00 fixture going bad, which we only have one of. *We tried to
substitute the 067-0589-00 fixture in place of it and pull the + & -
signals off of it, but the frequency response was even worse, on the
order of -12% at points. *What is the main difference between the
067-0655-00 and the 067-0589-00? *The 0655 looks like they've spent
significant effort shielding the pickoff points, and the 0589 has a
little more unshielded coax showing. *However, the flexible extender
board has a similar amount of unshielded coax to the 0589 and seems to
pass the signals just fine. *Is it just the rolloff of the coax used
in the 0589?

Are there any engineers out there that worked on the 7000's still
around?

Thanks for any help,

Steve