Sale on Oscilloscopes

Hey folks, this post will probably age poorly, but for any of you who like tinkering with radio electronics, a decent oscilloscope is a must. Rigol is my brand of choice - a good blend between value, engineering quality, usability, and reliability. If you don't get lucky scoring vintage HP or Tektronix gear, a new Rigol is a pretty decent use of your cash I think. And occasionally they go on sale, which they are right now, and that's why I'm posting. They're offering a 2-channel 100MHz digital storage oscilloscope for $250 USD, and that's less expensive than a bunch of the cheaply made garbage you find on the bargain sites, considering the quality. If you just need a solid, basic oscilloscope to do repair work or learn how to work with circuits, or to teach signals, etc., this is a really excellent deal in a time of things being hard to get your hands on and prices skyrocketing. Jump on this, if that's you.

To keep this post from aging badly, though, we can also use it as a jumping off point for oscilloscope discussion and technique, if you all want to!

Sweet Tatorman's picture

I am happy to see that there is another forum member with some technical background. Based upon what I can ascertain from those that post enough to make a judgement, I have concluded we are few in number. Several times I have considered starting a technical topic but refrained as the audience appears to be limited. I am a test equipment junkie whose personnal lab would be over $50K worth if adjusted to original new retail and current $USD. Most of the really high dollar stuff was purchased used at pennies on the dollar and over half of that $50K would be accounted for by a couple of HP spectrum analyzers. The highest priced item purchased new would be a dual channel Tektronics 2211 digital scope that in current dollars would be ~$4K. It was one of the very earliest digital scopes. I have had it for about 30 years and it has been a real workhorse for me. It will be a sad day if it ever goes belly up. I have often been tempted to buy a used one to hold in reserve. A feature that I really like and would require on any future scope is on screen cursors that permit measurement in both the voltage domain and time domain. I like that all controls are analog which is something that would be hard to find in a modern scope. As an old guy that still misses the rotary dial phones I despise the on screen menu style of user interface.

I am very much looking for that balance of "appropriate technology" in this day and age, and tracking that balance as it shifts during our global trends towards lower energy lifestyles, so it's a pleasure to see other people treading the same path.

Like you, I prefer hands-on controls for my 'scopes. I own a mixed-signal DSO with a touchscreen (Rigol MSO5000 series), but fortunately the majority of the controls are still real knobs and buttons and it feels overall very much like the Tek and HP scopes I used in university - in fact, better than the new ones and is equally usable as the vintage ones in the audio signals lab (which were mostly of the 1970's and 1980's vintage), although not as tactilely pleasant. I like me some clicky switches, what can I say.

Mostly I use my scope for small microcontroller development (STM32 series ARM Cortex-M4 and M7, sometimes dual-core work), since I do both the hardware and software development for various projects. I haven't gotten into RF yet but I'm hoping to soon enough, as I'm getting back into amateur radio more seriously.

Sounds like you've got a very nice lab. I'm still needing to be highly mobile and low-footprint so I've only got the 'scope and an SMD solder station/hot air rework unit as my "lab", but with 4 analogue channels and 16 digital (simultaneously1) I can manage all the projects I've had to tackle so far, at least.

As an aside, I find Apollo 11 technology to be deeply fascinating - it's a little higher than my line for "appropriate tech", but they had to do a lot of clever and quite often surprisingly simple things to solve some of their problems - the relay switchers in the DSKY module (an early 300V electroluminescent display module, couldn't use FETs to switch that voltage then!) are a great example. And of course there are some folks in Russia who are starting to make Nixie tubes from raw materials (glass tubes, a bottle of neon, metal plate, etc) again. These are all fancy processes that require a lot of high tech lab materials, but they're well within the range of "human comprehensible" and doable, if they're needed. As we scale down, I'm quite curious in seeing what level of electronics we end up keeping (aside from the small subsets of increasingly disconnected high-tech bubbles, which I exclude) in the main.

Another thing I find interesting to think about is the "simple" tech: wires, basic semiconductors, resistors and capacitors, tubes. Even making these basic fundamentals is not trivial without industrial equipment -- at least, at any useful precision - how would you be able to make even a simple d'arsonval mechanism without some way to calibrate full-scale current accurately, some way to make copper wire, some way to find and shape an appropriate magnet, etc? This is clearly at least a few steps beyond even fairly advanced blacksmithing, so it's unlikely to be available even in every large town.

But that level of "downslope" is much further away than my lifetime, most likely - there will be reclaimation of scrap long before that, and the remnants of industry and warehouse stock and various repurposed bits and bobs in the nearer term, so it's more hypothetical.

Still, the question of "what tech is even appropriate today" is not an easy one to answer and I think there isn't one single answer to be given. I'm reminded of Wendell Berry's beautiful set of requirements for any new technology:

1. The new tool should be cheaper than the one it replaces.
2. It should be at least as small in scale as the one it replaces.
3. It should do work that is clearly and demonstrably better than the one it replaces.
4. It should use less energy than the one it replaces.
5. If possible, it should use some form of solar energy, such as that of the body.
6. It should be repairable by a person of ordinary intelligence, provided that he or she has the necessary tools.
7. It should be purchasable and repairable as near to home as possible.
8. It should come from a small, privately owned shop or store that will take it back for maintenance and repair.
9. It should not replace or disrupt anything good that already exists, and this includes family and community relationships.

lathechuck's picture

... include a Philips PM2232 0-10 MHz dual-beam model, purchased probably within a year of my first professional paycheck. A few years ago, I won a student-grade Tek dual-trace scope at an on-line auction, with the caveat that one of the input channels was flaky. I may have paid $5-10 for it. I eventually discovered that the problem with the flaky channel was a total lack of solder between the BNC jack and the first component "connected" to the center pin. Somebody just forgot to hit it during manufacturing, and the dry pressure contact was enough that it mostly sort of worked for a while. Eventually, I sold it for (probably) $40 to an audiophile /synth enthusiast who thought he needed to "see his music".

Sweet Tatorman's picture

As mentioned elsewhere in this thread I am a bit of a test equipment junkie. I can endorse a very capable bench power supply which I just now purchased my second one off of Ebay from a seller that has 8 of them. BIN price is $160 but seller accepted my offer of $125 which is a very good price for this item. I will provide Ebay link below. My first one suffered a mishap when an item under test that I was powering had a failure that sent a high energy pulse of several kV back into the power supply. It has been in a state of partial disassembly next to my dinning table for a month and I troubleshoot a bit as the mood strikes me. Past experience suggests that I will eventually repair it but I thought I would check Ebay to hedge my bets and found this good deal. The power supply in question is an Instek GPD-3303S. It has extremely accurate readouts of voltage and current and is capable of 6A up to 30V or 3A up to 60 volts. It has dual main outputs as well as a 3rd channel of fixed voltages of 2.5/3.3/5V. It is the best bench power supply (of many) that I have owned. Link below: