a homage to ohmage

That is a true masterpiece. Beautiful.

A selector switch of that many poles can be quite expensive

Thats NICE! You put your finger on it when you said "art work".

Based on where you're located, the knobs, binding posts, and workmanship, I'd say this is an internal HP test jig from the 1960s made either for the lab or production engineering. The parts look like they're all from parts bins in lab stock at HP but that sort of soldering and free-flying wiring would never pass muster for a production product. Another clue: that missing name plate from the upper left corner of the panel looks like it once held an HP instrument badge.

@IMSAIGuy

9 ай бұрын

It does look very HP. Was confused when I first saw it

@sleibson

9 ай бұрын

We built a lot of internal-only tools at HP and this looks like one @@IMSAIGuy

Nice project for a restoration.

It looks very much like student DIY equipment from the 1960ies. Relatively much effort is spent on the outer design, the markings, and the complex switch. The resistors are mostly 10% carbon resistors, mixed with a few 5% types and at least one 1% type. Today one can get a 7-decades 1% resistor array for about 10$ and connect it to 7 cheap thumb-wheel switches for easy setting and reading. Unfortunately the wiring of the thumb-wheel switches is made in a way so that one has to solder 70 connections.

"There ya go, good as new!" - Classic!

Carbon comp there some drift there. 20% on a good day with those. Fun video.

@davebleamwa2bxy799

9 ай бұрын

I threw out all my carbon comp resistors: even the ones in sealed packages aged to +20%.

That's so awesome. Beautiful yet janky as hell lol. I just ordered a new resistor box from China I'm tempted to review when it comes.

After a lifetime of electronics I honestly don't remember a single occasion where I needed one of these. Same goes for caps, inductors , or any of their ilk. 😄

@stephentrier5569

9 ай бұрын

I have a couple. They have been useful for working out what resistor gives a desired LED brightness and to help a kid get a hands-on understanding of RC circuits. But honestly I haven't had a lot of use for them.

@Graeme_Lastname

9 ай бұрын

@stephentrier5569 They seem like such a good idea. 😜

If nothing else you have an interesting project box ...

Good video. Possibly you could buy a 5% 1W resistor kit to get most of the values. The kits are not perfect by any means but also aren’t very expensive.

I didn't expect to see that inside 😂 It's huge!

Please restore, it would be a great video on restoring old equipment.

Beautifuly made, nightmare to work on.

The rotary knobs and sockets look like they are from HP, but I don't know that they would make something like that. Nice day 🙂 Tom

One idea for working on it if you decide to do so, is to note the position, but cut the vertical bus wires, which would be easy to replace, then disassemble the switch. That would free each individual wafer, and ring. Just a thought.

Oh wow that really is a work of art

@lmamakos

9 ай бұрын

"art"

@airmann90

9 ай бұрын

@@lmamakos exactly. Lol

@danishnative9555

9 ай бұрын

Lol. A masterpiece at that.

@IMSAIGuy

9 ай бұрын

definitely 'post modern'

That construction style is almost identical to a capacitor and inductor box I'm making for myself. Though mine are only E6 across 4 ranges, rather than your E12 and 6.

A good video.

Rather that try to get 1 of every value, another method would be to use 1W SMD resistors, and use 1R and 2R values for each decade so 5x 1ohm and 20 x 2ohm would make up the first decade, i.e. 7ohm is 3 x 2R and 1x 1R in series. That way you can buy cut tape in 10's and the cost is a lot better plus you get 1% resistors. Andy

I'd rebuild it with 1/4 watt 1% metal films and change the marking to 1/4 watt max

An E12 sub-box, send to me. I'll fix it, clean it up, and get a label for it. Leave the dings and signs of use because they add a je ne sais quoi. Love fixing older stuff, just mo longer have the room for the ship anchors. 😂 BTW, who dafuk is that fif, a bot?

If they made the outer rings separate you could take the switch apart wafer by wafer to get access to everything. I guess you could still do that by snipping the outer ring and making it into separate rings.

Pre-PCB electronics keep amazing me

Are the color wires of the gain selector related to the order of magnitude by which the desired "impedance" is multiplied? because they are ordered 1, brown, 2 red, 3 orange...

Now that's one for the Bone Yard. Not much to salvage either.

@simontay4851

9 ай бұрын

The rotary switches and the box are salvageable.

Really nice layout with value * exponent, unfortunately probably needs a complete rebuild. Maybe you can find some hobbiest to gift to that would like to do that

I built my own resistance substitution box... out of cussedness mainly. It... ... didn't look as good as this one. 😅 If it's really home made that's impressive!

I think someone used a dead HP instrument module and modified it

Obviously a DIY project from many moons ago. All the labels are off, along with the resistor values. Time for the circular bin 😮

@EssArrB

9 ай бұрын

or a trainee / apprentice project?

I hope he wasn't invisible! impe-dance....dancing in our socks! always moving forward! -->---->---->---->---->---->---->-->

How did you clean the rotary switches?

@IMSAIGuy

9 ай бұрын

sprayed them with contact cleaner

Faradage & Henrage?

Definitely looks "homemade." Doubt it was something mass produced.

Voltage👍Wattage👍Amperage👍Ohmage😒???😮

May not be the latest and greatest design but the battery will last forever.

@IMSAIGuy

9 ай бұрын

that's good since I could not find a replacement.

Are you sure that's not the main computer out of a Tesla? It looks about as high tech as Elon Musk and his asskisser's would use.