[Test-Equipment] HP-410B VTVM probe cables question

[Robert Myers]

I have an HP-410B VTVM.  

1.  Can someone tell me why the DC voltage probe connection to the HP-410B
consists of a shielded cable while the Ohms probe connection is a just an
insulated wire - or at least on mine the Ohms probe cable is that way (is
that correct for the Ohms probe?).  

So, is the shield really needed on the DC Volts probe?

2.  Also, can someone tell me the original specification for the triax cable
that connects the RF probe (i.e. AC Volts) to the HP-410B?  It shows an HP
part number, but I think it was probably a Belden triax cable.

I am wondering if any newer more flexible triax cable capable of handling
the voltages work?  If so, what should its characteristic impedance be (or
does it matter, as it should be carrying only DC volts created from the
rectified AC/RF)?

Thanks,
--- Rob Myers, VE3JQL