What’s your favorite test instrument?

January 20, 2012 By 11 Comments
Simpson Model 60 VOM

The venerable Simpson Model 60 VOM has been in production for more than 60 years.

In the Test&Measurement World group on LinkedIn, editor Martin Rowe asks, “What’s your favorite test instrument”? He gets some interesting answers, but the two top vote-getters are the Bird Model 43 Wattmeter and the Simpson Electric Model 60 VOM (see right).

About the Bird wattmeter, one engineer said, “That’s easy – The Bird Model 43 Wattmeter. No other instrument has been in production, in its original design, for so long. Since 1952, which makes next year 2012 its 60th anniversary. Also, it must be the simplest, most rugged instrument ever produced. We regularly see Model 43 Wattmeters returned to us for calibration that are 30-40 years old, still working and, when they leave our facility, as accurate as the day they first came of the production line in Solon, Ohio.”

About the Simpson VOM, another replied, “My favorite test instrument of all time is the Simpson 260. I used it back in the 1970s while serving in the US Navy. It is rugged, easy to use, and does the job!”

Those are really two classics, and either is a great choice. But, what do  you think? What’s your favorite test instrument?

Filed Under: Test Equipment

From the Twittersphere

January 14, 2012 By Leave a Comment

The Twittersphere is kind of like the ionosphere. It helps you make contact with other hams and brings you news from far and wide. Here are a few interesting links that I found on Twitter in the last day or so:

Global Pirate HF Weekend 14-15.1.2012.  This station lists pirate SW radio stations that it expects to be on the air this weekend. They include one using the callsign WEMP. Look for it between 15.005 – 15.095 MHz. They’ll be broadcasting with 100 W to Europe: 12.00 – 16.00 UTC – (check 15.010 or 15.040 or 15.090 MHz).

The Evil Mad Scientist Laboratories Zener Diode Tutorial. Confused about zener diodes and how they work? Read this.

Monitor your Ham Radio transmitter with an oscilloscope. In this video, Alan, W2AEW builds a little adapter that lets you connect your transmitter output to a scope input so that you can see how clean its output is.

Filed Under: Electronic Components, SWLing, Test Equipment

Hack a Day: Use an Arduino to Measure Inductance

July 26, 2011 By Leave a Comment

It’s been over a year since I built an Arduino microcontroller at our club’s annual construction night, and I still haven’t done anything with it. I’ve had a couple of ideas, including a keyer that would actuate accept paddle inputs and actuate a solenoid that would open and close a straight key, but just haven’t had the time or inclination to actually put something together.

Well, here’s a cool idea as to how to use an Arduino to measure inductance.

Measure inductance with an ArduinoA signal in from the Arduino excites an LC circuit. The L in the LC circuit is our unknown inductor. The output of the LM339 is a square wave whose frequency is proportional to the L of the LC circuit. Measure that frequency with the Arduino and you know the unknown inductance. Of course, calibrating this thing could be a bit tricky, but it might be fun to play with.

Filed Under: Building/Homebrew, Microcontrollers, Test Equipment

Device Tests PowerPole Outlets

June 16, 2011 By 1 Comment

PowerPole Voltage and Polarity CheckerI just found a link to this unique little device and had to blog about it right away.  The PowerPole Polarity and Voltage Tester is similar to one of those little devices that you plug into an AC outlet that tells you if the outlet is wired correctly. Except that you plug this device into an unknown PowerPole outlet.

What  surprised me is that this little device actually uses a microcontroller to measure the voltage. I guess that I really shouldn’t be surprised, though. Microcontrollers come in very small packages now, and programming them is very simple to do .

Because microcontroller are programmable, you could extend the functionality of this device. For example, you could add a small alpha-numeric display or more LEDs to indicate different voltage ranges.

While the circuit is very simple, and is easily fabricated on some perfboard, the author of this Instructables project, has indicated that he intends to make a PC board and kit available. I’ve e-mailed him about this, and will report on what he has to say about price and availability.

Another thought that occurs to me is that I could make one of these with the Arduino that’s been languishing beneath my workbench for the last year or so. Basically, I’d just take the front end circuitry from this project and connect it up to my Arduino. I’d have to do some programming, but I think I can handle that. :)

 

Filed Under: Building/Homebrew, Test Equipment

Multimeter Links to iPhone or iPad

May 18, 2011 By Leave a Comment

Redfish iDVMHere’s an interesting new product—the iDVM Multimeter—a product the company claims is the first digital phone-enabled multimeter. As you can see, the instrument itself has no display or controls. All display and control is done through an iPhone or iPad app.

The connection to the iPhone or iPad is a Bluetooth link. The app allows users to acquire, visualize, and share electrical measurement data on their Apple devices. Data can also be exported and e-mailed for further analysis.

The kicker is that the instrument won’t ship until June, and it will cost $220! A Fluke 177 multimeter costs only $240, and undoubtedly has much better analog specs. (The “Technical Specs” page on the Redfish website is currently not available.) It does do some things that the Fluke doesn’t do, such as speak the measurements and use a rechargeable battery, but I’m not sure those features are worth the price.

I like the iDVM concept a lot, but I’m afraid that they’re going to have to reduce the cost of this thing by at least 50% to be successful.

Filed Under: Test Equipment

Is Now the Time to Buy a Tek Scope?

May 6, 2011 By Leave a Comment

Having your own scope is a real pleasure. I’ve had one myself for the last 20 years or more. When you really need to look at a signal, you just hook up the scope and you can see the waveform. It’s beautiful.

There are many places that you can be a used oscilloscope for a reasonable price. Ham radio operators have been getting by with industry castoffs for years. Now, however, it might be time to think about buying your first, new oscilloscope. Tektronix is holding what they’re calling their 2011 Scope Sales Event. The sale runs through July 1, 2011.

New scopes, like this TDS2000C, are amazingly versatile when compared to scopes that amateurs typically use.

You can save 10% on TDS2000C series scopes (see right), 25% on MSO/DPO2000 Series scopes, and 10% on the MSO/DPO3000 Series scopes. For example, you can get a 200-MHz TDS2022C with two analog inputs for only $1,854. A two-input 100-MHz TD2012C is only $1,308.

Not only are these scopes (relatively) inexpensive, they’re much easier to use and fully-featured than older models. For example, the TDS2000C series uses an LCD display, meaning the scope is more like a small, flat-panel TV, and it takes up a lot less bench space than the older scopes. They also have a whole range of analysis features that the older scopes don’t have.

A scope is one of those things that you never knew you needed until you have one. And, once you have one, you wonder how you ever did without it. Now, with the cost of a new scope about the same price as a mid-level transceiver, perhaps it’s time that you got one of your own.

Filed Under: Gear/Gadgets, Test Equipment

NIST Conducting Time and Frequency Survey

March 25, 2011 By Leave a Comment

NISTDo you use NIST radio station WWV or WWVH? Do you have a radio-controlled clock or set your computer clock using NIST? Do you get NIST time via telephone or Internet?

Please take a moment to complete the NIST Time and Frequency Services survey. Your input will be greatly appreciated.

By the way, you might also want to visit the NIST Time and Frequency Division website. It has a bunch of interesting info for time and frequency geeks.

For example, currently there’s a piece on the world’s most precise clock. It says:

NIST scientists have built a second “quantum logic clock,” using quantum information processing techniques on a single ion of aluminum to make a clock that would not gain or lose more than one second in about 3.7 billion years.

Filed Under: Test Equipment Tagged With: ,

From the Trade Mags

December 15, 2010 By Leave a Comment

I’m on the distribution list for many different electronics trade magazines. Quite often, there are articles of interest to amateur radio operators. Here are four of them—two from electronic design and two from EE Times—that I hope you’ll find interesting.

Radiated efficiency: A true measure of antenna performance
Many engineers tend to think of antennas in terms of gain, but the author argues that we’d be better off if instead we evaluated antennas in terms of efficiency, that is how well it turns the power supplied to the feedpoint into radiated energy.

And You Thought The 555 Timer Was Dead?
Recently, both Advanced Linear Devices and Semtech have redesigned the 555 timer chip, improving it in many ways and extending its usefulness—most likely—for years to come.

Melville Eastham: Workplace Innovator Crafts Early Electronic Products
Eastham was the founder of General Radio. The article points out that Eastham founded the company in 1915 to “serve the rapidly growing ham radio market.” By the late 1920s, that “boom” had subsided, and the company turned its attention to precision measurement instruments. It was very successful doing this for many, many years.

10 Technologies to Watch in 2011
This article predicts that “wireless connects for health care” will be one of the technologies to watch in 2011. Makers of medical electronics equipment, apparently, are planning to integrate their gear using Bluetooth.

Filed Under: antennas, Electronic Components, Test Equipment Tagged With: , ,

Random Links

September 10, 2010 By 5 Comments

Here are a bunch of random links to interesting and useful websites:

  • 1×1 Callsign Search. It’s often difficult to know who’s using a 1×1 special-event callsign. Looking them up on QRZ.Com doesn’t work because they’re only issued for short-term use, and they are re-used over and over. To help you identify that 1×1 callsign, the W5YI VEC has set up this searchable database. Type in a call, and it tells you who’s used the call recently and who will be using it in the near future. Very cool.
  • Arcane Radio Trivia. True to its name, this blog has all sorts of radio trivia. For example, a couple of the latest posts cover a 1920s radio show called Midnight Frolic that ran on WMC in Memphis, TN and the February 1930 issue of Radio News magazine. The latter is available as a PDF for download.
  • This item is from the 9/1/10 ARRL Contest Update: Why is 10.7 used to determine the solar flux index? Spaceweather published this interesting article that explains why.
  • Radio Sky Publishing: Resources for Amateur Radio Astronomers, Students, and Teachers. If you have any interest at all in radio astronomy, check out this website. It’s been very slow for me, though, so be prepared to wait. I’m waiting right now for the “Beginner Tips” page to load.
Filed Under: Online Resources, Special Events, Test Equipment

You Get What You Pay For

June 9, 2010 By 9 Comments

At the Maker Faire on Saturday, I pulled out my $2 Harbor Freight DMM to check the continuity of the light bulb in my “visualize RF” demo. Bad news. The “low battery” indicator was on, and apparently it couldn’t supply enough current to make the measurement. On top of that, as I was fooling around with it, the wire came off one of the probes.

Well, yesterday, I tried to fix things. I re-soldered the probe wire and replaced the 9 V battery, but the meter’s still non-functional. The display comes on, but I’m not able to make any measurements.

I guess the moral of the story is that you get what you pay for. I now have another cheap $2 Harbor Freight DMM in my tool chest. We’ll see how long this one lasts.

Filed Under: Test Equipment Tagged With:
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