0006 - Build a Precision Substitution Resistor for under $20. 

I had the exact same idea for a substitution box, though I have yet to build it. I did build a bench pot from the same 10K pot. I gave it a heavy, non-skid base and a 3" round circle, for a knob. I added a wide rubber band to the side of the knob. This gives traction, so that I can dial in a setting with just one finger. I used rather small alligator clips on the wires. It is one of my best bench tools. Kudos!

I like it. Thanks. I have a couple of old lab grade decade boxes from a physics lab that modernized. But they take up a big chunk of my bench work space. I have a handful of .01% and .005% resistors of various values, but they are seldom the values I need. I also have a box of precision wire-wound pots that I didn't have any special use for. So I have everything I need for this project, and I can compare it against the big resistor reference boxes. In fact, I think I'll build 2, since there is often a need for a pair of matched values. Again, thanks. I use grounding strips from home circuit-breaker boxes as bus bars on my bench since they have all of the screws on them for that purpose, and junk ones from old breaker boxes are essentially free.

I forgot to mention a DIY bus bar... Very handy for making multiple connections. I have one, but I want to improve it. Presently, I have just one, narrow, solid-core wire, on a block of wood, with attachment wires, which have alligator clips. I intended it as a ground bar (hence the alligator clip to attach it to GND/chassis) and it has been very handy for that purpose. The solid-core wire is bent in a "U" shape and the ends are glued into the block. I will improve this by 1) having multiple separate bar blocks 2) have each bar on a jumper - this will allow a DMM to be inserted to take current readings [my brother's idea = kudos to him] 3) add an output switch to each rail to be able to take that rail out of the circuit... I guess the switch could be on the input-side of the rail. Which would you suggest and why? Well, you could just turn the bar 180* to make the switch on the input, or output. But, still, the question remains as to the better side. I am sure it is contingent upon the rig's configuration. Please and thank you. Sorry that this is written poorly; I am in pain. But, you get the idea. Art Linkletter said getting old ain't for sissies.

I have single ten turn pots in individual boxes. This is a very good idea to get any value, 0 to 100k, precisely.

I like DIY projects

Good idea !

This assumes that your DMM is correct. You're basically turning knobs until you see the number you want if it was a precision resistor box you could set it to precision from the numbers on the POT's

You get less smoke by omitting the 100R pot & fit a 2w 100R resistor . But it messes up the precision a bit …...

are those knob markings accurate when paired with those pots?

Very nice Channel! Good Content u produce!

I do not understand the point of the dials??? You have 10/5 turn pots and a DMM, the dials mean nothing.