Opting for an Optical Tme Domain Reflectometer (OTDR)

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Choosing an Optical Time Domain Reflectometer (OTDR) is very similar to the process used in selecting a new vehicle. The more options that are included – or added – the more it will cost. Some OTDRs are built with rugged utilities for heavy field use, others are delicate precision instruments suitable for laboratory use. Any high-quality OTDR is a significant expense; most cost as much – or more – than the majority of new motor vehicles. The same amount of thoughtful consideration used to buy a car should be used in selecting and buying an OTDR.

An OTDR is a complex instrument incorporating optical frequency pulse generators, a spectrum analyzer, and supporting user interface to determine the location of faults, relative impedance, signal degradation due to attenuation or deformity in the fiber, and often has a computer interface or plug-in modules to allow a separate computer access to the test and measurement device and data for more sophisticated online or offline analysis than may be available from the instrument alone.

Operating Environment

The first and most important consideration is where and how the OTDR is deployed when it is in use. Exposure to extreme weather, limited availability of electric power, and the required degree of portability eliminate any OTDR that isn’t ruggedized, battery powered, and reasonably sized, such as a hand-held. A rigid bench, wheeled carriage or rack mount unit used in a power- and climate-controlled clean room or engineering laboratory environment dictates a completely different set of options. It may be required that the OTDR is dual use, and trade-offs must be considered to determine the best value balanced against the risk of potential damage when in transport or in active use.

Operational Capabilities

Acquiring an OTDR should not be solely based on financial or budgetary considerations. Cost does not necessarily translate to effectiveness; a very expensive unit can be totally unsuited to measure the cable under test. If a unit is simply to be used to determine the location of a break in the cable and not more esoteric measurements, such as impedance mismatch, kinks or sharp bends, attenuation or signal losses, then it can be much less expensive than a full-feature instrument of otherwise similar size and utility.

New, Discontinued, Factory Refurbished or Used: Which is the best choice?

The only reasons to buy a new, bleeding side of the cutting edge technology are that the company is a manufacturer or the application is mission-critical. Often, a discontinued instrument offers substantial savings and superior value – often 30% or more – especially if it is a brand-new unit, simply no longer manufactured. A factory refurbished instrument meets or possibly exceeds the original specifications. These units are typically factory warranty returns, leased instruments, trade-ins for upgrade to newer models and similar light-use applications reconditioned by the OEM for resale. Savings of 30% to 50% are not unreasonable expectations. Used instruments can offer very high value, however, due diligence is required to ensure ample time – typically 30-90 days – for inspection and return privileges if the unit fails to perform. Cosmetic exterior wear and tear consistent with its operating environment are not uncommon. Used units that perform to specification can realize values from 60% to 90% below the original MSRP.

Brand name or OEM?

Some people are comforted by particular makes and models of test equipment. In many cases, the difference between a name-brand device and its OEM equivalent are cosmetic – the internal circuitry is identical. The wise buyer will consider the specifications before the name brand, the reliability and integrity of the source of the equipment and the particular requirements of the technician or engineer that will use the equipment. The length and scope of any warranty or guarantee must also be considered, especially with used instruments. Is the warranty a factory warranty or outsourced to an unspecified third-party?

Relative value

An OTDR can easily cost 20 to 50 thousand dollars or more. Used OTDRs can also cost 40 thousand dollars or more. A capital expense item of the magnitude of an OTDR can have significant tax implications. The ROI of a used unit often is much faster than a similar new instrument and it can have a steeper depreciation. Before purchasing an OTDR, it is suggested that the engineering staff that will be using the device, the accounting staff that will handle the budgeting and payments, and the executive officers that will have to justify the expense, be in agreement. This can be difficult; however, the use of an independent third-party systems consultant can often provide assistance in coordinating the various aspects of an acquisition with minimal impact on limited corporate resources. Before opting for a low-cost solution, consider the functionality, specifications, and usability requirements of the tasks that the instrument will be used for.

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Hearing is Seeing – with the OrCam

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Imagine yourself walking to the refrigerator of your local supermarket, with a quest for 1% strawberry flavored yogurt and not being able to distinguish between the 0%, 1%, 3%, and full fat containers, not to mention the chocolate, coffee, vanilla, strawberry, peach, and natural flavors. Why not? Because you are visually impaired.

Or.

Entering a library to check out Volume Three of War and Peace, and not being able to distinguish between the titles of the four volumes (plus epilogue) of this huge literary masterpiece.

At this point, you should be asking how people who are visually impaired are able to read non-Braille books anyway.

So, read on – and listen up!

OrCam, a young (2010) Israeli company has designed an audio device that uses visual sensors to light up the world for the visually-impaired. The device, consisting of a “seeing” sensor and an audio output that externally uses the little bones of the ear to conduct the signals coming from the sensor, is attached to a pair of glasses – yours or theirs – creating what OrCam cites as Artificial Vision. Just point to the object you want to read or see, then the OrCam sees it for you, and reads it to you.

Watch the video to see how the OrCam works and what it can do.

Here are some fascinating features of the OrCam:

  • Easy to learn and easy to use.
  • Reads to you from books, newspapers, and product descriptions.
  • Lets you distinguish between similar looking objects, for example different brands of cereal.
  • Is pre-programmed with a number of commonly known objects.
  • Can learn or edit objects based on your own familiar surroundings.
  • Can learn to recognize people you know and to remember their names.
  • Works with your own prescription glasses or frames from the company. Can even work with sunglasses.
  • Can operate with a hearing aid.
  • Intended for the visually-impaired but also a powerful aid for people with dyslexia or for sufferers of memory loss.
  • Currently priced at $2500, which seems like a small investment for such a huge quality-of-life improvement.

And here are some musings about the product:

  • Amazing how the sensor can distinguish between red and green traffic lights. But how about black and blue socks in a drawers? Does it have the sensitivity to read (and learn) duller colors or less distinguishable colors?
  • Can the sensor read script or handwriting?
  • Does the device use OCR, that is, Optical Character Recognition? Or is it really Object Character Recognition? In other words, is the same technology used to sense characters (such as letters and numbers) as well as objects, such as people, food products, and vehicles?
  • What powers the Orcam? How many hours of use are provided?
  • Although currently programmed to work with common, everyday objects, can it potentially be used in specialized areas of research; designing it to work in areas where more than 20/20 vision is required? Or where unusual, uncommon objects can be programmed to be recognized?

My late Father was visually-impaired, and then legally blind for most of his adult life. How he could have benefited from an aid such as this!

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Six Top Reasons for Listing your Inventory on Used-Line.com

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Here’s the windup...

BaseBall Windup

Baseball Windup (Microsoft Office Image)

You mean you need a reason? Ok, so fine, we’ll give you six reasons. All six reasons are based on points that Used-Line customers have already made about Used-Line’s portal for used test, lab, and semiconductor equipment.

Used-Line appreciates customer feedback, both positive and negative. Well, mostly positive! But we are always ready to learn from our customers.

Let’s make one thing clear. There aren’t only six reasons for listing your equipment on Used-Line.com. We’re simply listing the TOP six reasons here. Our blog post would become a lengthy dissertation if we were to list them all. And you would probably get the point by the time you read Reason #73.

The six reasons we chose are those that we garnered from our customers’ feedback. You can read what our customers have said in their own words in our customer testimonials. Thank you, Used-Line customers!

…And here’s the pitch.
Baseball Pitch

Baseball Pitch (Microsoft Office Image) 

1. EXPOSURE

Used-Line exposes you to a large potential customer base. Used-Line visitors, whether dealers in the market for buying or selling equipment, or private buyers and sellers, learn to trust those users they conduct transactions with on Used-Line. It is easy on Used-Line to build your own network of long-term trustworthy dealers and customers because of the solid framework for conducting your business and because of the vast selection of equipment listings.

2. ADVERTISING RESOURCES

Billboards. Banners. Listings. Your own promotions.

Plane Banner

Plane Banner (Edited Microsoft Office Image)

The advertising packages available on Used-Line are both numerous and flexible. You can be up and running in a few minutes. A first-time visitor to the site can advertise his equipment in a listing right away, simply by completing an online form. For our more sophisticated brand boosting options or for a custom-designed strategy, you can contact a Used-Line Sales Rep directly. Used-Line understands that its users have many different requirements and budgets and, as a result, Used-Line offers many flexible options.

3. EXPANDING BORDERS
There is no need to restrict your customer base to a couple of city blocks.
Of course, borders in our world have fallen away with the globalization of markets via the Internet. However, Used-Line’s international Dealer Directory provides instant contact with a vast listing of registered dealers from all over the world. This both broadens your customer base, and gives you access to hard-to-find equipment that may be available in locales at a distance from your physical location.

4. TRIAL PERIOD
The one-month free trial of Used-Line advertising lets you test the system and examine your results. You should be able to gauge the potential ROI during this first month, as well as view your results with the Used-Line Statistics feature.

5. PRICE
Price means different things to different people. Price can mean the cost of your expenses for selling equipment via Used-Line. Price can mean the selling price of your equipment. Whatever it means to you, on Used-Line, you can find the price that works for you. If your equipment is on the lower end of the pricing scale, you will be able to find a pricing scheme for selling your equipment that may cost you nothing or next-to-nothing, but which will get you top dollar for your equipment. On the other hand, you can choose a budget-friendly package with the best results for selling your high-end equipment.

6. CUSTOMER SERVICE
A smile. A fast response time. Friendly advice. Flexibility. Full attention to your specific requirements. Professional. Goes the “extra mile”.

Need we say more?


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Three Test & Measurement Instruments You Can Create with a Smartphone

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Should I be embarrassed to even admit that I don’t own any kind of smartphone? I own a Kindle. Does that count? Somehow, I don’t think so.

But despite not being able to try this out for myself unless I borrow my brother-in-law’s iPhone or my  niece’s Android phone, this is the first thing that has really tickled my fancy about smartphones (aside from Waze).
3 Test & Measurement Instruments You Can Create with a Smartphone Signal Generator, mixed signal… Click To Tweet

Test & Measurement Instruments

Test & Measurement Instruments

Anyway, back to the topic. I’m talking about turning your smartphone into a test & measurement instrument. Not a surprising development. And not that new, either. For some time now, we’ve been watching T&M instruments approach the size of smartphones. Handheld T&M instruments, while not necessarily offering the type of specs you’d find on a benchtop, have been finding their niche in the market as engineers are called upon more and more to leave their benches and go out into the field without the inconvenience of a heavy bag.

I don’t think smartphones are ruggedized enough yet to withstand the conditions that handheld T&M instruments are built for, although according to an article in the National Instruments Developer Zone, smartphones do have the potential to at the very least take over handheld  meters in the field.

Anyway, let’s take a look at just a few sample products (there are many more out there), and see what we can measure with a smartphone.

 The ‘Scope on a Phone

This should be a cinch, right? Simply show voltage over time? Yes, but what scope leads do you use? Do you need some sort of external hardware module? If you short two pins on your Device Under Test – will you fry your smartphone? What happens if your phone rings while you’re checking the output on pin 3 of your 7400? (I did not invent this question!)

In 2010, Onyx Apps introduced Oscilloscope 1.0 for iOS. The write-up on DailyAppShow describes the features and capabilities of this app, which can also generate sine, square, triangle, and sawtooth waveforms up to 22 kHz. Instead of using the  audio input, which is somewhat limiting in terms of sampling and frequency, the Onyx scope app uses the microphone or a device plugged into the microphone input. Today, Version 1.9 is available. This app offers many of the typical features you would find on a desktop oscilloscope, such as triggering modes (Normal, Single, and Auto), screen capturing ability, reference signal calibration, and more.

The Mixed Signal ‘Scope on a Phone

Believe it or not!

How did they do that? We can thank Oscium for its Model iMSO-104 mixed signal oscilloscope (MSO) for iPad and iPhone, which consists of a module that includes one 8-bit analog channel and a four-input digital harness.
3 Test & Measurement Instruments You Can Create with a Smartphone Signal Generator, mixed signal… Click To Tweet
You might need something a little more serious for devices in the GHz range, but with a 5 MHz analog bandwidth, a sample rate of 12 MS, and the ability to instantly probe a circuit from a tiny device powered by an iPhone or iPad, who’s complaining? The software app is super user-friendly, replacing knobs and buttons easily with those adept key strokes and finger swipes.

Here are some interesting pointers I learned from the FAQ on the Oscium site:

  • The analog channel can be used for measuring AC or DC. Maximum voltage range is -40 V to +40 V (10x mode).
  • Digital threshold is 1.7 V (fixed).
  • Triggering is available up to 100 ms. What’s really cool is that if your timescale goes higher, the triggering menu disappears. Although this can be scary when you first encounter this phenomenon, it’s a user-friendly tip once you’ve learned why or when this occurs.
  • The IMSO-104 is supported by iOS version 5.0 or higher.

 A Do-It-Yourself Signal Generator

Test & Measurement Instruments

Test & Measurement Instruments

An article that appeared this month in an EDN Network newsletter does not consider the 20 Hz to 20 kHz frequency range of a smartphone’s audio plug to be a limitation. There’s a lot you can do in this range. The article suggests that many of the components in medical devices fit into the lower end of the range. Here are some examples found on the National Instruments site:

  • ECG (or EKG): 0.01 – 300 Hz
  • EEG (electroencephalogram): 0.1 – 100 Hz
  • EOG (electrooculograph): 0.1 – 10 Hz
  • EMG (electromyograph): 50 Hz – 3 kHz

With the availability of hardware and software for less than $20 (not counting the cost of the smartphone!), and some light labor (get out your soldering iron) you can be up and running in no time with two channels (your left and right stereo connections) generating sine, square, and sawtooth signals.


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On Views, ClickThroughs, and RFQs: Tracking your Listings on Used-Line

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If you’re wondering why your listings on Used-Line.com generate many VIEWS, but a very low CTR (Clickthrough Rate) with a decided lack in RFQs, then you are asking the right questions.

How do you check if your ad (listing) is getting the views but not the clickthroughs?

Used-Line now offers a Statistics service that can show you all the activity taking place on your listings – both individual and overall listings. We previously discussed how to write a good sell ad for Used-Line. Now let’s find out if you really do need to work on your ads – or if, in fact, you are doing OK.

The new Used-Line Statistics service can tell you how your listings are doing by providing you with:

  • Instant views of the effectiveness of your listings overall
  • The ability to drill down into the specific statistics of individual ads

Okay. So how do we retrieve all this important information?

To view overall Statistics of all your Used-Line listings for each month

  1. Log in to your Used-Line account.
  2. To view overall statistics of all your listings, click Statistics under My Used-Line on the left side of the page. View statistics for your total listings for each month in the following four graphs:
    • RFQs received: Indicates how many Used-Line buyers sent you a Request for Quote (RFQ) for items you advertised.

      RFQs received

      RFQs received

    • Views – product pages: Indicates how many potential buyers saw your postings.

      How many users viewed listings

      How many users viewed your postings

    • Click-throughs to site: Indicates how many Used-Line visitors visited your company website.

      Number of click-throughs to your site

      Click-throughs to your site

    • Click – view phone: Indicates how many Used-Line visitors clicked the Seller phone number button in your ads.

      Number of users that clicked your Phone button.

      Number of users that clicked the Phone button.

To view statistics for your individual listings

  1. If you have not already done so, log in to your Used-Line account.
  2. To view individual listing statistics, click My Ads under My Used-Line on the left side of the page. Each ad is in the ItemID column in the My Ads tab. You can view the specific statistics for each of your ads in the four columns to the right of the ItemId column:
    • Views: The number of potential buyers that viewed the ad since it was first posted
    • Site: The number of Used-Line visitors that visited your company website by clicking the Visit Website button in the ad
    • RFQ: The number of RFQs that have been sent for the item you described in the ad
    • Phone: The number of Used-Line visitors that have clicked the Seller phone number button in the ad

Note: At times, you may want to update a listing because of new or changed information. This is fine, as long as you realize that your listing will be reset. When a listing is reset, the statistics for that listing are reset. As a result, only the statistics for the most recent version of your ad will be shown.

So, let’s get tracking!


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Wearing the Internet, or, Do I Need an Eye Exam for Google Glass?

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Yes, I know everyone has already written about it. Google Glass is old news (not really, it’s new news -but it’s old in that everyone knows about it already). It’s passé (writing about it, that is). But I just can not pass up on anything that looks so Borglike. So, resistance is futile. You’ll have to read this umpteenth blog on Google Glass.

When the term, “wearing” Google Glass, was first coined, I must admit I expected some sort of shirt made out of opaque glass with your choice of colors. Well, at least, I did get one thing right – the color choices. Right now, you can get Glass in Charcoal, Tangerine, Shale, Cotton, and Sky. It wouldn’t surprise me if you can find matching colors at the Gap.

Right, so it’s not a shirt. It actually looks like goggles. Strictly speaking, one-eyed goggles. Even more strictly speaking – right-eyed goggles. I don’t believe there is a lefty version yet. I guess they couldn’t call it Google Goggles, because Google Goggles already exists as a mobile application that sends images to do your searching for you. Which I’m guessing (I’m not that sure) Google Glass can do for you, or if not now, will do so in the near future.

I’m not here to review Google Glass. I couldn’t possibly do that without trying it out. Just google Google Glass and you’ll find all the reviews you want. I’m hear to express my fascination with the concept of actually wearing something that you can chat to, ask directions of, send commands to, sent text messages with, photograph with, share stuff through, check stuff with, get information from, search with. Look, Ma, no-hands Internet! I’m sure Ma is thrilled.

l just have one kvetch. Why is everyone calling it Glass? As in, with Glass you can can send videos in real-time. Glass lets you send text messages. Get your flight arrival information from Glass. Why is Glass personified? Glass isn’t my next-door neighbor. Glass isn’t even a Borg. It’s just a piece of equipment.To me, glass is that ubiquitous substance that you make out of sand and it’s only capitalized when it’s the first word in a sentence. Google Glass is not (yet) ubiquitous and I’m sure it will take a while before I can pour my soda into it.

But I look forward to the day when Google Glass will get sold on Used-Line!

And, no, I doubt you need an eye exam to wear Glass. But what do you do with your prescription glasses while wearing Google Glass? Seems it could be a little awkward wearing Glass together with your eyeglasses. Do you need to wear contact lenses? Have laser eye surgery? Well, I shall have to go and google Glass and find out!


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Why not rent? (Part two of two)

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In the last blog, I introduced a  February 2013 Scope Junction article that delivers the results of a survey on scope rentals. Readers were asked how often they had rented an oscilloscope. Of the 152 users who responded, more than 53% answered in the negative – they had never rented a scope.

Part One of this blog discussed a couple of points to consider if you are thinking about renting or leasing equipment instead of purchasing. Affordability was weighed against cost-effectiveness and the number of variables that can impact the ultimate cost of an instrument . As well, predicting the future of the industry was considered a factor in rental decisions.

Here are a couple more considerations.

Flexibility. You can rent state-of-the-art equipment that your budget does not allow you to purchase. For specific projects with stringent high-end specification requirements, a short-term rental lets you perform specialized tasks that you normally would not be able to run without the unique instrumentation features or specifications required for them. And – without breaking the bank. Although the flexibility of this type of short-term rental is attractive, it does demand more than a comfort level with the specs in order to match those required by the project with the capabilities of the instrument you intend to rent.

Test-drive an instrument. While renting, you can gauge an instrument’s performance strengths and weaknesses in your lab. Many instrument dealerships offer both rental and leasing terms. After leasing for a particular time period, you may be offered purchasing options at reduced terms. At this point, you should be able to clearly assess the suitability of the instrument as a permanent fixture in your lab.

And now for a little bonus tidbit. Or should I call that tipbit?

How to Find Dealers that Rent Out Equipment on Used-Line.com

The Used-Line Dealer Directory lists more than 900 dealers. How do you locate those that do offer rental equipment as one of their services?

  1. On the Used-Line.com home page, click DEALER DIRECTORY in the column on the right side of the page.
  2. In the Dealer Directory, use the filter on the left side of the page to choose the type of equipment you need: T&M, Lab, or Semi.
  3. Narrow your search further by Location and by product Specialization.
  4. Open the Services list, then select Rentals to view all the companies that offer rentals in the type of equipment you need.

    DD Services with Rentals

    DD services with rentals

 


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Why not rent? (Part one of two)

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In a February 2013 Scope Junction article, Michael Dunn delivers the results of a survey on scope rentals. Readers were asked how often they had rented an oscilloscope. Of the 152 users who responded, more than 53% answered in the negative – they had never rented a scope.

I’m wondering – why not?

Well, I know that there is that warm, fuzzy feeling one gets from owning one’s own stuff. There’s also the Guiltfree Factor. If you own something, you don’t get that oh-no-it’s-not-mine reaction when you spill your morning coffee on the bezel.
But, emotional issues aside, what’s on the plus side for renting a scope – or any piece of test or laboratory equipment? Here are just a few well-known, but worth repeating, advantages of renting equipment.

Affordability. Rental can be more affordable than purchasing, particularly for short-term periods and if support and maintenance are included in the terms. However, the cost of both renting or purchasing equipment needs to be carefully calculated. There are many variables, including natural depreciation of the instrument, usage, the condition of the instrument (new, used, refurbished, calibrated), specifications, configurations, need for support and repair, and yes, even size. The cost of a portable spectrum analyzer, for example, cannot be calculated using the same formula as one would use to cost a roto-molding independent-arm machine. Every company must, of course, use its own formulae for calculating the cost-effectiveness of renting or purchasing equipment.

No need to be an industry prophet. When you purchase, you need to factor in the future. When you rent, you can, well, not ignore, but somewhat downplay the effects of depreciation, usage, repairs, growth and changes in the industry, and internal turbulence within your company. You need not spend too much time wondering how much dust your instrument may be gathering at the end of the warranty period, or whether it will still be happily chugging along. A child’s “I need it now” philosophy very much suits the rental option. A year down the line is not really significant because you can swap the unit, or simply not renew the rental contract.

Stay tuned for part two, in which I’ll talk about a couple more rental considerations, and more.


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It’s All in the Tool

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TRAVELLING BACK IN TIME

So there I was in front of the kitchen sink, scrubbing this pot that had at least eight years of grime stuck to it, having realized that I don’t want to keep serving Chicken Cacciatore left over from January 2013 to my family. Nor that delicious pot roast in wine sauce that I concocted in March 2012. I mean, both beef and wine do age well, but we’re talking health hazards here – not epicurean tastes.
So, sighing with muscle fatigue, regretting that I had stopped popping in to the neighborhood gym park some time ago, and realizing that the only iron I was pumping these days was beneath the enamel of the above-mentioned pot, I opted for a coffee break, using my left hand to pour (my right arm having ceased to function normally after its scrubbing aerobics), and decided to rest for a few minutes and ponder the tackling of this task.

coffeeCoffee always inspires! I remembered! The green baize scrubby thingy works wonders! Well, not exactly baize – more like a rough green plasticy sheet that feels gentler than sandpaper but works in the same way. After a thorough search for a piece of the green wonder (the coffee gave me the energy to do this), I found some of this treasure in the drawer at the bottom of a kitchen closet that only opens if all the other doors in the room are closed (Don’t even ask!). A few minutes inside my pot, after taking another rest to recover from the drawer/closet battle, and I could view my own reflection inside my suddenly-like-new pot!

DON’T LET THE EQUIPMENT BEAT YOU! YOU CAN DO THIS!

This ultimately successful experience reminded me that winning battles with equipment is all in the tool! It threw me back to my technician days at Bull HN Information Systems. H = Honeywell, and N = NEC. If you are too young to have heard of Groupe Bull (pronounced Bee-yool in France, home of the company’s corporate headquarters) in their Honeywell days, here’s a link to a little history about Honeywell and it’s relationship with Bull.

Don’t Let The Equipment Beat You! You Can Do This! Click To Tweet

A BRAND NEW & PROUD ELECTRONICS ENGINEERING TECHNICIAN

Proud to have graduated as an electronics engineering technician from Seneca College, Toronto, I arrived at my first job in 1991 – at Bull’s Component Repair shop in Scarborough, Ontario, eager to try out my new troubleshooting skills with a DMM and scope. My analytical skills knew no bounds. Really, all you need to know to succeed in this work are a few logic gate specs and some sort of expectations about what should be showing up on those pins: 5 V, maybe 3.3 V, 0 V. Some interesting waveforms on the screen. Right?

Wrong!

INFORMATIVE REPAIR REQUISITION SLIPS

So, first things first. Read the complaint written on the Repair Requisition slip. These can be very informative.
Like this one:
“Dead”.

A DEAD DUMB TERMINAL?!

That’s quite useful information. Usually it produces the avoidance response. Avoid powering up the instrument. Avoid calling up the customer to enquire, “So what’s actually wrong with the instrument?” Why not just avoid trying to repair it?

Not an option.

LET’S CLIMB INSIDE A MONOCHROME HONEYWELL DPS

Okay, then, let’s take a look INSIDE! My job was to repair monochrome monitors and Honeywell DPS “dumb” terminals. The terminals weren’t really dumb – but after a while, the technician (yours truly) got to feel like not such a bright spark.

In order to view the inside of the instrument, you need to open it up. How I struggled to open those boxes. On my first day on the job, I was presented with a set of tools including a power screwdriver, all shiny and red.

It had a forward/reverse button and I had two bits for it, a Phillips and a flathead. As soon as I saw it, I thought, “This is it!” This tool will take me anywhere I need to go.
As it turned out – not everywhere.

Well, after ruining the threads of almost every screw on the terminal, I bashfully, in a rather subdued voice, approached my co-workers for advice. “Help me, help me, help!”, she cried. After ensuring that there were no hunters chasing after little rabbits, (Scarborough, Ontario not really being a cottage-in-the-woods kinda place) three technicians called out in unison: “It’s All in The Tool”!

I dropped my powered screwdriver like a hot cake, and trying to be brave, dared to ask, “What tool?!”

Screwdriver in toolbox

THE POWER OF PHILLIPS SCREWDRIVERS

And out they came – the powerful, yes, but not powered – the wonderful Phillips screwdrivers in all shapes, sizes, and lengths. Why did I not have one of these in my default tool set? Because they all came from Dad’s toolbox in his shed in the backyard. Note that ISO 9002 came later – we were still basking in the days of unrestricted shop conditions. They went on to explain that the power screwdrivers are fine for many tasks but not for those stubborn screws that have become embedded in plastic after years of heating. It’s guaranteed that they will want to remain right where they are. But, wait, there’s more.

THEY DID NOT TEACH ME ABOUT TORQUE IN SCHOOL

It’s not only in the tool, my new instructors cried – it’s also in the torque. Torque? And then my new-found instructors taught me how to use the tool. Choose the correct size screwdriver, position the tool correctly in the screw, apply pressure. and only then, turn. Fortunately, those were the days preceding my need to take coffee breaks each time I applied a little torque, else I would probably have been responsible for breaking some sort of Union law relating to multiple coffee breaks.

THANK YOU, BULL HN COMPONENT REPAIR IN SCARBOROUGH, ONTARIO

After that, opening equipment became a breeze. I couldn’t wait to pass on my new-found knowledge to the new wet-behind-the-ears recruits, who, like me, thought they knew it all. Now, so many years later, I would like to thank my co-workers in Bull HN Component Repair for their patience, excellent skills, and teaching abilities. I really appreciated all your assistance. Thank you!


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Basic BERT

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Not that a BERT is a basic instrument by any means. But I thought (while still in a techie mode – or would that be mood?) that I would bring you a pretty basic article on quite a complex test and measurement instrument. So grab a cup of coffee, curl up in front of your screen, and enjoy!

The Bit Error Rate Tester (BERT) is the test and measurement (T&M) device of choice when checking transmission and reception quality over telecommunications lines. These lines can be copper-to-copper, twisted pairs – such as Ethernet – coaxial cable, cellular phone (as 4GLTE) or fiber optics. Typically, all of these methods are used and they are often run through radio frequency repeaters, microwave, or satellite links. The BERT is also used to troubleshoot for problem areas, check repairs to circuits, and used to test alternate or secondary (fallback) transmission paths.

The BERT’s function is to stress test transmission lines to isolate sources of noise, jitter, intermittent connections and impedance mismatching. There are several types of stress testing. These can include maximum voltage throughput, as when sending all ones (1s), minimum voltages tests as all zeros (0s), forward error correction (ECC) and error detection and correction overhead. Alternating or pseudorandom bit streams are used to simulate typical traffic over the lines. There are far too many mathematical models and engineered algorithms to list in detail, but they are critical in the selection of the equipment.

BERTs can use a variety of multiplex and modulation modes, the more common commercial systems using some form of Phase Shift Keying (PSK) and other forms of signal concatenation. The major components of a BERT include a modulator/demodulator (“modem”) to connect the BERT to the transmission lines, a pattern generator, a clock to synchronize BERTs and establish baseline timing, an error detector, often some sort of digital analyzer to visually observe or record the devices under test, and a computer interface.

The complexity of digital transmission necessitates the use of equally complex – and generally expensive – specialized test equipment. The cost can easily be doubled when end-to-end testing from both termination points is required. As a practical rule, most tests can be run using farside or nearside loopbacks, which allow a single BERT to generate the patterns and detect errors sent back to itself via the loopback.

HP/Agilent and Tektronix BERTs dominate the field in this particular technology; however, Anritsu  has a long history of manufacturing leading edge telecommunications test and measurement equipment. More than 95% of the BERTS costing $10K and up are made by these manufacturers. Features, flexibility, and suitability to a purpose have resulted in some very expensive — $100K BERT test systems. Systems designed to a single purpose, such as DS line testing, can be much more affordable. For the field technician, companies such as Fluke and GAO handheld BERTs provide techs with rugged, durable, and portable solutions. Options such as pass-through of the original traffic can be a valuable asset when making live tests or in mission-critical applications, where the transmission line cannot be taken completely out of service.

Necessity for super-high frequency (SHF) and extremely high output (EHF) and input frequencies, USB 3.0, the most recent Windows O/S, and similar hardware and software user interfaces are all desirable features that can add significant cost to a unit. What used to be considered frills and gimmicks are now required features.

HP/Agilent and Tektronix have different approaches to the same issues, yet in the end, the results are the same. Without putting too fine a point on it, Tektronix instruments are more conducive to the laboratory/engineering set, while HP/Agilent is more focused on the field/maintenance group. This is a purely subjective opinion, generally based on an individual’s tastes rather than specific features. What is far more valuable is the capabilities of whichever BERT is preferred. Does it operate at the frequencies required? Can it generate the patterns necessary for test and evaluation? Is the instrument modular or easily upgradable without factory intervention? Which BERT has the best ROI potential?

Handheld portable units are much easier to compare, since they are more likely to be designed for a specific communications protocol, as T1/DS1, E1, or OC1. Desirable features in all handhelds, regardless of protocol or interface, are durability under extreme field conditions, the ability to bridge or pass-through communication modes that are transparent to the traffic, and enough flexibility to meet any reasonable situation likely to be encountered. Often the answer is defined by the question: Would you rather drop an $8000 HP or an $800 Fluke, given that both are testing an identical circuit?

As the telecommunications network is continuously evolving, it is necessary to keep your T&M as close to the leading edge as possible. Competition is too intense and customer demands are too critical to try to short-cut on quality control and rapid response to a call for repair. Top of the line, stable, and trustworthy T&M can save many times its cost by ensuring high uptime and low mean time to repair networks and transmission lines.

Ready to compare some Berts – both new and discontinued? Check them out in Used-LIne T&M Specifications.


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