Recommendations for Beginner Test Equipment - Page 1
Forum section: electronics / testgear

author: DM
author_rank: Newbie
timestamp: March 23, 2019, 02:49:05 am
content: Hi, I am a Computer Engineering student looking for beginner test equipment for personal and school use. I am in labs at school that I thoroughly enjoy and find quite interesting, however it would be nice to have some equipment at home for personal projects and so I have a set of my own equipment. I don't really have a set budget in mind but would prefer to find older equipment off of Ebay to keep costs down. For my major I will be taking classes such as Advanced Digital System Design, Electronic Circuits I and II, Microcontrollers, Signals and Systems, etc. I do plan on continuing my education afterwards to specialize in some form of Electrical Engineering. The equipment that we use in lab are the following:Agilent E3631Agilent 33120AAgilent 34401AMSOX2012ABasically I am looking for older oscilloscopes (DSO), function generators, multimeters, and power supplies. If possible can you link similar threads and/or give advise on what I should look for?Thank you very much-DM

author: 0culus
author_rank: Super Contributor
timestamp: March 23, 2019, 03:00:14 am
content: Here's a list of the things I have in my lab. My interests veer towards RF and higher, so I've been buying equipment with that in mind.Tek 2465B oscilloscope (I need a DSO too at some point, but not crucial at the moment)Keithley 2231 triple output power supply (it's a rebadge, but it's solid and works great)HP 3325B synthesizer/function generatorHP 8657A signal generatorHP 8644A signal generatorHP 5335A universal counterHP 5350B microwave counterHP 8569B spectrum analyzerHP 8568B spectrum analyzerHP 8566A spectrum analyzerHP 3455A voltmeterAnd last, but not least, Tek TLA715 logic analyzer.I still have a good list of things I need to buy, especially in the department of test equipment needed for adjusting and calibrating all the test equipment listed above. But I've been able to have a lot of fun experimenting, and I've found pretty good deals on all of it. The goal is a state of the art RF lab, circa 1985. Counters are definitely a bit underrated, but you should have them. The 5335A is very capable and they can be had for reasonable prices. The fellow I bought mine from refurbishes them and periodically lists them on ebay. Let me know if you're interested and I can put you in contact directly.

author: DM
author_rank: Newbie
timestamp: March 23, 2019, 03:21:42 am
content: Thanks for the response but may I ask what a counter does exactly. From researching it looks like it mainly is used to view the frequency, period, and ratio between signals. What are some uses for it in a practical sense? I have never used one before so I'm just curious?

author: 0culus
author_rank: Super Contributor
timestamp: March 23, 2019, 03:33:24 am
content: Quote from: DM on March 23, 2019, 03:21:42 amIt does all those things, but more importantly, it is a lot more precise than an oscilloscope for measuring frequencies. I often use the 5335A in situations where I don't need to see the waveform but want to know it's there. It also does statistics and other math functions, which can be handy as well. The 5350B (20 GHz) only measures down to 1 Hz resolution, but the 5335A has enough digits to get into tiny fractions of a Hz if you need it to.

author: DM
author_rank: Newbie
timestamp: March 23, 2019, 03:45:09 am
content: Ah, I see. Also, would you recommend analog or digital test equipment? I understand that each have their pros and cons but for starting out does it really matter?

author: 0culus
author_rank: Super Contributor
timestamp: March 23, 2019, 03:51:49 am
content: Quote from: DM on March 23, 2019, 03:45:09 amOpinions on that will range I'm sure, but I think it's best to line up the pros and cons of each. Using oscilloscopes as an example, I feel that using an analog scope with all the knobs and controls on the front panel will teach you a lot more about running a scope than a new digital one with menus and soft keys and automatic measurements will. However, analog scopes are getting older. You either need to get one refurbished (this is what I did when I got the 2465B, because I knew I wanted an analog scope but also didn't want a project right away) or be prepared to do some repairs. On the bright side, this forum has lots of resources for doing this and older stuff will have service manuals. For me, there's nothing like ensuring that old high quality US made test equipment gets to live on.However...if you want to do things like single shot captures, decode bus protocols, etc., the advantages of a DSO are immediately obvious. While analog storage scopes do exist, that's probably not a can of worms a beginner wants to open.

author: DM
author_rank: Newbie
timestamp: March 23, 2019, 04:05:07 am
content: Yeah, unfortunately for my schooling a lot of the professors want screen captures of our waveforms and signals. I was personally looking into the Tektronix 2230 and 2232 Oscilloscope for personal use. Seems like it would have the best of both worlds.

author: 0culus
author_rank: Super Contributor
timestamp: March 23, 2019, 04:11:56 am
content: Quote from: DM on March 23, 2019, 04:05:07 amMakes sense. All hope is not lost for all older equipment, though. KE5FX (who I believe is a member here) (http://www.ke5fx.com/) has a nice GPIB toolkit that allows you to do a lot of things with GPIB equipped test equipment, including an emulator for the HP plotter that everyone used back in the day. Once I save up a bit for a GPIB adapter, I'm going to try it out for my spectrum analyzers.

author: David Hess
author_rank: Super Contributor
timestamp: March 23, 2019, 03:09:55 pm
content: Quote from: DM on March 23, 2019, 03:21:42 amBesides having two inputs, universal counters also generally have lower frequency high impedance inputs like an oscilloscope with more flexible triggering and coupling options. So they can also make rise/fall time measurements, inline measurements, measurements with a standard oscilloscope probe, delay measurements, gated measurements, etc. DSOs have largely replaced universal counters but with lower resolution and accuracy.Measuring the ratio between two signals used to be more important when this was a common analog to digital converter output form. It is possible to make a high resolution ADC to drive a universal counter with just a few parts.Quote from: DM on March 23, 2019, 04:05:07 amThe Tektronix 2230 and 2232 are the oldest DSOs that I would recommend simply because they were the first DSOs which supported peak detection and second to the last DSOs with full documentation. These oscilloscopes are old however and the advantages of analog operation (1) are marginal; it may be better to get a modern DSO and separate analog oscilloscope.While you can get digital screen captures out of a 2230 or 2232, I think it is actually better to use a good point-and-shoot camera because it will work equally well in analog or digital mode and can provide excellent results as shown below where I took the photographs freehand under less than ideal conditions. My camera is a Canon PowerShot SX150 IS selected because it operates on 2xAA cells, has optical image stabilization, and manual operation if needed. I try to avoid portable electronics which cannot use standard batteries. (2)(1) Like being able to measure RMS noise accurately unlike say a Rigol DSO but you could also get a modern inexpensive DSO which can if they exist.(2) Transferring photographs off of a camera is annoying. I am always afraid of breaking the USB port so now use a card reader but wireless in some form, especially optical, would be nice. Unfortunately most camera WiFi cards have to operate through the internet? Forget that!

author: 0culus
author_rank: Super Contributor
timestamp: March 23, 2019, 03:41:58 pm
content: David, those are very nice photography results. Keep in mind OP that oscilloscope cameras were a thing back in the old days.In fact, I've seen some rackmount Tek 485s that are equipped with a bizarre tiny CRT that I believe was optimized for photography and not for bench use.

author: Howardlong
author_rank: Super Contributor
timestamp: March 23, 2019, 04:35:45 pm
content: Bearing in mind you're a student and old school test equipment is bulky and heavy, would you consider an Analog Discovery (1 or 2) with the BNC adapter and probes? I'm not a USB scope fan by any stretch, but I do use the Analog Discovery quite a lot, mostly when I'm out and about, but also on the bench sometimes too. I'd have killed for something like it when I was an EE student 35 years ago!I don't use analogue scopes very much at all now, and although I like them, the last time I had one permanently on the bench was about four years ago: modern DSOs are so good nowadays, and can be purchased for a reasonable price. All the analogue scopes sit under the bench now :-(

author: DM
author_rank: Newbie
timestamp: March 23, 2019, 04:42:47 pm
content: Yeah our professor has talked about using analog scopes and how they would attach a camera to the display of the scope in order to capture the signal. One reason I was looking into the Tek 2230 and 2232 was because they are older scopes. I think that having a physical switch or knob would be more beneficial to learning what that option does rather than scrolling through menus.

author: DM
author_rank: Newbie
timestamp: March 23, 2019, 04:52:46 pm
content: Quote from: Howardlong on March 23, 2019, 04:35:45 pmI have briefly looked into them before but I would have to do some more research. I kind of like the big and bulky but I'm not opposed to something small like that. I will definitely read up on them!

author: David Hess
author_rank: Super Contributor
timestamp: March 23, 2019, 05:11:37 pm
content: Quote from: 0culus on March 23, 2019, 03:41:58 pmThose examples are just by hand and represent the lower bound of what is possible. The 2230 and 2232 include mounting points on the CRT bezel for a camera and several people have made them to use with modern cameras. Here is an example made for 7000 mainframe but the requirements are similar:http://www.amplifier.cd/Technische_Berichte/Photographie_Oszilloskop/Foto_Halterung.htmlQuoteThe 485 had a smaller than normal CRT anyway. The ones optimized for photography used a headache inducing blue phosphor.

author: HalFET
author_rank: Frequent Contributor
timestamp: March 23, 2019, 05:33:56 pm
content: Might be worth it to dumpster dive around campus (assuming that's considered ok over there), old analog scopes are often the first things people throw out when cleaning up a lab. But in terms of educational value I'd say the earlier analog/DSO hybrids were quite nice. You really had to know what you were doing when you tried to sample something with one of those.

author: tggzzz
author_rank: Super Contributor
timestamp: March 23, 2019, 05:53:15 pm
content: I'd advise the OP to:decide on a project, because that will indicate what is needed, as opposed desiredbuy the minimum necessary equipment, because every piece of equipment takes time to learn how to use itlearn to use each piece of equipment via simple experiments, to see what it does and how it lies to you (they all do, one way or another!)use them, and work out what you need for the next project - you will be in a better place to know what you don't need