Make up a laboratory from scratch.

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I'm with EC. The only thing I would add are a couple more cheap, (5$) DMMs, not so much for precision measurement but for watching things like PSU rails, things you don't need total accuracy for, but need to see if any gross changes occur under fault conditions or initial testing.
 

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pinkmouse said:
I'm with EC. The only thing I would add are a couple more cheap, (5$) DMMs, not so much for precision measurement but for watching things like PSU rails, things you don't need total accuracy for, but need to see if any gross changes occur under fault conditions or initial testing.


I am with EC too, and I agree with pinkmouse about the DMMs, with a small twist: a couple of those analog multimeters you can buy at the supermarket for $5 can come in handy, instead of the DMMs.

Somebody mentionned lots of cables, crocodile clips, etc. I agree with that too.

6 1/2 digit DMMs and Rhode-Schwarz distortion analyzer? Yeah, sure, I think they have these at Harman-Kardon and NAD, Carver must have a few too, plus a few more R&D facilities, but I never even came near one...

I guess it will be a long time before I need 6 1/2 digits resolution for my PS voltage measurements. ;)

A good used scope is around 100 pounds, as EC wrote. Start with that and a good workbench (I assume you already have the multimeter).
 
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Hi Stefanoo,

I am with EC too as I did misunderstand your question. I use many plastic boxes containing smaller one, and I label all what I put inside, else I would never find again what I need when needed. I group the boxes in a desk as categories of items : transistors, capacitors, resistors, metallic stuff ...

Look at the workbench of pinkmouse : you want that kind of workbench. Mine is not so beautiful, but it is partly metallic, a diy one. As I did it, I find it very very OK.

Best regards

rephil
 
pinkmouse said:
I'm with EC. The only thing I would add are a couple more cheap, (5$) DMMs, not so much for precision measurement but for watching things like PSU rails, things you don't need total accuracy for, but need to see if any gross changes occur under fault conditions or initial testing.




Thats like 5 dmm's LOL..
 
integrated test software

i use Audio Test Bench for a lot of different things, including EQ'ing rooms.
http://www.higherfi.com/softwar5.htm

i also find this spectrum analyzer software to be quite useful:
http://www.qsl.net/dl4yhf/
it's intended use is for ham radio DSP, but if you browse the various setup menus, you will find that it can do a whole lot more (it seems like it's an audio engineering lab in a sound card). it has a flow-chart based setup as well, that is simple to use, but very flexible.

also, for design work, i found that the limitations of various SPICE demo programs were too restrictive(even the TI "Tina" SPICE software has low node number limitations, but i use it for small subcircuit design). the SPICE program from Linear Technology, however, has no restrictions, but it does not have a THD calculation (a little math with the spectrum graph is close enough, however). you also might want to use low pass filtering with their simulated sine wave source, since it's odd harmonic content is about -50db. their software is available here:
http://www.linear.com/company/software.jsp


all of these programs are freeware, and very useful to me.

i'm also designing a "front end" to use my sound card as an o-scope and function generator with Audio Test Bench. it will have voltage dividers, so i can use it with signals up to about 300V p-p, and will have an output buffer for the function generator. i will post schematics, layouts, and test results when it's finished.
 
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jleaman said:
Thats like 5 dmm's LOL..

You really can't have too many meters. You need one (or perhaps two) good ones, and some cheap ones. Moving coil meters react faster than digital and can be useful for warning of impending smoke release.

I've added a picture of my bench. The inverted black guttering (lined with kitchen foil) shields the direct light from the 1.5m fluorescent and gives plenty of diffuse light on the bench surface.
 

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I've added a picture of my bench.
EC, thats a nice lab, indeed:)
Thats like 5 dmm's LOL..
Yeah, 5 would be nice.
Being in the proces of adjusting an A-X right now, I could easily use 2 more than the 2 I have. Some cheapo's will surely do.
What do you guy's think of the PC based "all in one" systems offered these days? (scope, distortion analyser, sound generator...) Sure would save a lot of space.

Steen:)
 
pinkmouse said:
Very nice bench EC. Is that an Alpha 10 I see up there? I have one too, but mine is off the road at the moment with a damaged DAVE module.

Jason, I have two more out of shot. ;)


Yup always good to have. I bought my Fluke 87 for 35$ fixed it and then sent it off to calibration and its perfect. 35$ for a mint meter works for me :d

the next thing on my bench i want is a dual mode psu with pos neg & gnd so i can work on small low current projects instead of building the psu for it.
 
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PC oscilloscopes? Not with a sterilized barge pole.

steenoe said:
What spec's are important to look for regarding a scope, for DIY hifi use?

Probably the most important specification for an oscilloscope is one that isn't specified - the triggering. Lots of older oscilloscopes had very poor triggering. Tektronix have traditionally had very good triggering and other manufacturers have had to catch up. For DIY Hi-Fi use though, almost anything will do. Most 20MHz oscilloscopes are sold for teaching use in universities etc and will do fine. Professional electronics engineers generally prefer a Tek, and if they've ever had anything to do with video they want dual timebase.

Digital: You don't want it. Cheap digital oscilloscopes spend most of their time housekeeping rather than capturing information. Further, unless they have plenty of record length combined with high sample rate, they alias. Digital is only worth it if you can afford to pay the money for digital done properly.

Finally, remember that an oscilloscope is a tool. Analogue oscilloscopes have had years of being honed so that the controls are in logical places and make the tool intuitive to use. You can forget all that when using a PC-based oscilloscope.

A coal shovel might have a blade and a handle but if you need to dig a hole in the ground you need a proper spade...
 
I have been thinking of buying one of the picoscopes for a long time, but I think they are too expensive and the general opinion appears to be in favor of analog scopes, so I have found this:

Tektronix 464 - 100MHz scope from 1980 with two 10:1 probes.

The price is approx USD270 - is that expensive?
 
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cviller said:
Tektronix 464 - 100MHz scope from 1980 with two 10:1 probes.

The price is approx USD270 - is that expensive?

Are you sure it's a 464? I'm familiar with the 465 (100MHz two channel from that era).

There's something I ought to warn you about with old 100MHz Tek 'scopes. The vertical amplifiers are 100MHz and have to swing quite a healthy voltage. Getting decent bandwidth simultaneously needs fragile transistors (to get the required low capacitances) and high currents (to charge those capacitances quickly). The common solution is to fabricate the vertical amplifiers as a hybrid circuit (which is part way between a true IC and a small PCB) as this further reduces stray capacitances. Trouble is, the company that made the hybrids for Tek went out of business and Tek no longer have any stock. Further, those hybrids run hot and can fail. The upshot is that if you buy an old >100MHz oscilloscope and one of the output transistors fails in the vertical deflection hybrid, you're sunk.

Bearing that in mind, I wouldn't really want to spend more than US$200 on an oscilloscope that might fail suddenly and be unrepairable. Conversely, an old 20MHz Gould uses readily available discrete transistors and is maintainable for ever. Alternatively, you might want to consider a new analogue oscilloscope...
 
EC8010 said:
... Trouble is, the company that made the hybrids for Tek went out of business and Tek no longer have any stock. Further, those hybrids run hot and can fail. The upshot is that if you buy an old >100MHz oscilloscope and one of the output transistors fails in the vertical deflection hybrid, you're sunk.
...
EC is right, Tektronix oscilloscopes use special hybrids that are no longer available, that makes servicing these units a pain.
I am not sure if this problem affects all the Tek scopes or just some models.
I use to have a 2215A (sold a long time ago) and now have a 2225 (bought used a month ago). Tek rotary switches are fantastic quality and I believe even though these scopes were built in the early 90's, they'll last a few more years.
I would recommend any one of the 22xx scopes, they are not too old, built to last and well though out.
 
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