Tag: keithley

Fake National Instruments GPIB-USB-HS converter (and NI not caring about it) (WHL #87)

Niche hardware again for today, a USB to GPIB/IEEE-488 converter from National Instruments. Or at least what the Chinese have deemed necessary for a functional copy…but first things first.

This adapter was bought at work for connecting an ancient beast of a scope (a LeCroy LC334 – 4 channel, 500MHz/2GSa/s, 400W, 20kg spread across 50 liters of chassis volume, 9″ 640×480 color CRT) to a modern computer. While that sounds crazy (well, it is), that old hulk was purchased with a current probe, which is actually very useful for a current (ha!) […]

7 decade thumbwheel resistor box (project #P1)

A while ago, I wrote articles about a bargain SMD resistor set (WHL #10 ) as well as some thumbwheel switches (WHL #11). Let’s start fresh in 2017 and present the final box :)

As already shown in the thumbwheel post, the initial resistor placement wasn’t perfect. I fiddled some more and I got a case and nice 4mm banana plugs for it. First, let’s see the final measurement results, done with a calibrated Keithley 2700 6 1/2 digit DMM in 4-Wire (Kelvin) mode.

Original performance:

Final performance:

Yep, the 1Ω data point still violates the 1%/10000ppm spec (1,9%). […]