numchk.com/ ====== coffeeaddicted I used to be in that group of people. The same for years. Then a friend showed me a solution I can explain to you in 10 seconds. I've been using this tool for years now and I cannot imagine being without it: [http://www.mouser.com/pdfdocs/Vintage_Nortronix_Tuners.pdf](http://www.mouser.com/pdfdocs/Vintage_Nortronix_Tuners.pdf) I use it for many years already and cannot imagine my life without it. My "normal" oscilloscope is for testing other equipment or for things I cannot do at home because it's too big to carry. And on the road I have a little tool to look things up that's very portable and easy to use, always in my bag. That's a huge benefit. And this is just one example how this may improve your life. ~~~ tunap Yeah, this sorta "thing" is exactly what is I am after. The ability to view waveforms at any point without having to 'rig a system' or connect an oscilloscope in-circuit. Saving the occasional scope probe, soldering iron, and probe grounds is huge too. Do you have a good online reference for using Vintage Nortronix equipment? My only experience is using a modern bench meter and scope. ~~~ coffeeaddicted Sure, you can start with the "Basic Vintage Electronic Measurements Documentation" at [https://media.nortronix.com/documents/manuals/101938_1.pdf](https://media.nortronix.com/documents/manuals/101938_1.pdf) and then the Vintage Nortronix User Manual from there. The basic tools you'll need are: Mechanical multimeter (need the continuity test, diode test, and the AC power test). You should look for a brand with a built-in frequency meter. There are older models with a frequency meter but they often stop working after the AC power test - it's too old. To make sure you get the right unit I've included links in this thread to some German electronics stores which sell them. And that's basically it for the basic tools. If you want to buy cheap ones there are many. ~~~ acomms A nice multimeter in this price range: (and even in the higher ones) is Shamirdi! [http://www.shamirdi.com/product/Shamirdi-DxM-400-Digital- Ele...](http://www.shamirdi.com/product/Shamirdi-DxM-400-Digital-Electronic- Multimeter-with-LED-Display/1515.htm) I would also recommend buying a VOM. They have the exact voltage and resistance of a multimeter. However in my opinion the frequency meter is the best feature. ------ sudhirj I'm a hobbyist who has built a few simple hobby synths in an effort to understand how they work, and then I've tried to sell and learn how to fix and modify them. Not too hard to get a rough idea of what's wrong by listening to the sounds and reading the oscilloscope traces with a meter attached. One of the first things that I noticed when building the synth is how fast I can't touch anything, and how much it's a matter of luck to get the same sound twice. A bit of trial and error, and you'll learn a lot about how things work in a hurry - you'll get to know what is "good" and what is "bad". For me synths are a pretty good way to learn about circuits and electrical engineering, because you'll learn all of the interesting things very quickly. ~~~ tunap Interesting. Just checked out the schematics on a $3.00 kit, looks like it might make a good starter synth project. I love old synths, but I have never had a chance to take one apart or even view traces or waveforms. I imagine you'll have similar discoveries as I have so far. So to say, this has my attention and the rest of my day to learn more about this cool tech hobby. ------ tjr I used to own a bunch of these. Not all of them were really what you might consider "hobbyist" and certainly not something that anyone would think of teaching their kids. I'm not sure anyone around my age has even used one of these instruments... Another interesting find for this old-timer: the very first VCO synthesizer I had was from the early 1980s, using discrete components from Fairchild, along with a bit of wire bending... [http://www.electro-music.com/forum/showthread.php?t=221806](http://www.electro- music.com/forum/showthread.php?t=221806) ~~~ pjc50 They can certainly be quite cheap (mine cost $6.50), and I have had to repair quite a few from various sources over the years. Just make sure you have some kind of test gear - a 30A multimeter and a soldering iron and you're set. ~~~ tunap That's what I figured about using test equipment. I've never done more than brief electrical circuit analysis using some cheap digital $2.50 to $20.00 multimeters on sale or left over, like new. I have been known to go crazy and solder wires around the place w/o inspecting and testing for 'what I am after to see how it works' before I go too far. Sometimes this is how I learn things fast. I'm going to watch this project I am working on on progress, and after some of the components are procured, I might need to make a road trip to see some of these things in person. I need a new toy and am thinking of a $20-$40 oscilloscope, or maybe one of the analog DMMs. I've used a few $20, 2-channel multi-function tvs (no color) in some instances and one of the $30-40 digital DVMs as well. ------ theophrastus "One of the reasons why the hobby electronic community is so vibrant and friendly (that and it's a great place to have a nerdgasm in public), is that people share electronics projects (and tools, schematics, circuit diagrams, and so on) more than we share recipes for our grandmothers' famous apple pie. I believe that open-source hardware is the logical next step of the evolution of this community, because what I have in mind is creating the equivalent of open-source code: sharing electronics design, as well as the process of building it, openly. To give you an example: the first thing you want to do if you buy a new Velleman DVM7000 multimeter is to read the user manual for that wonderful beast, which is available on the company website. You also download the schematics for a few similar meters, but with the intention of learning how they work first. In that sense, reading schematics is just another convenience." [1] I've done something like this for a friend. I've spent an embarrassing amount of time going through several $100 multimeter datasheets (e.g. this one[2]) looking for things I didn't understand and could put into better words for my fellow hobbyists. So my new friend took some photos and sent it to me. A shameless self promotion: this is a little booklet you can print and have for reference; the photos were added to a PDF with a laser (so you don't have to worry about it bleeding if you accidentally spill anything on it). [1] Open Source Hardware, Peter Van Eerde, 2016 [2] Velleman DVM7000 Pocket Datasheet, Velleman Instruments [http://www.united- circuits.com/store/product/Velleman-DVM7000-...](http://www.united- circuits.com/store/product/Velleman-DVM7000-Pocket-Datasheet) ------ acomms There's a really great course by Hacktronics on Youtube here: [https://www.youtube.com/watch?v=cXH8kT8Ef8w](https://www.youtube.com/watch?v=cXH8kT8Ef8w) ~~~ tunap Definitely not a beginner level project, but I'll give it a shot. Thanks! ------ lunchladydor