21 Things to Do: Buy a DMM

21 Things to Do After Getting Your Amateur Radio LicenseA digital multimeter, or DMM for short, is the most basic piece of test equipment you can own, and every ham should have one. With a digital multimeter (DMM), you can make voltage, current, and resistance measurements. Some multimeters do even more, but that’s a topic for another book.

Why do you need a multimeter? Well, the multimeter is the first thing you’ll reach for when you have problems with your equipment. For example, let’s say you go down to your shack, switch on your radio, and nothing. It doesn’t turn on. The first thing you should check in this case is that the power supply is supplying the proper input voltage. To do this, you pull out your DMM, set it to measure voltage, place the probes on the + and – outputs, and verify that the power supply is working.

Klein DMM

This multimeter costs about $50 and features a rugged case that helps prevent damage should you accidentally drop it.

OK, now we’re sure that the power supply is working OK, but the radio still doesn’t power up. The next thing to check is the power cable from the supply to the radio. It’s possible that the cable has an open connection. To check that, you first disconnect the cable from the power supply and from the radio.

This multimeter costs about $50 and features a rugged case that helps prevent damage should you accidentally drop it.Then, set your DMM to measure resistance. Set it on the lowest resistance scale. Connect one test probe to one end of the cable and the other test probe to the other end. The resistance you measure should be very low—less than 2 or 3 ohms. An open connection will register an infinite resistance.

I think you get the picture. Without a DMM, you’re dead in the water. With a DMM, you can figure out what’s wrong and fix it.

There are a wide range of DMMs available. On the low end, you’ll find DMMs at Harbor Freight for $5 or less. On the high end, you could spend $300 or more for a Fluke multimeter. I would advise against both. The $5 multimeters are not very well-made and can be inaccurate. They tend to quit working just when you need them.

The $300 DMMs are great, but you needn’t spend that much. A DMM costing between $30 and $100 will do pretty much all you need to do at this point in your amateur radio adventure, and you can use the money you have left over for other things. You can buy them at any Lowe’s or Home Depot. Ask your friends or Elmer what kind of meter they own and whether or not they would recommend that you buy something similar.

From the trade mags: modern transceiver design, twisted pairs

Here are a couple more articles from the engineering trade magazines.

High-performance HF transceiver design. This article describes some of the decisions that an engineer must make when designing a modern amateur radio transceiver. It also sheds some light on the test methods used to test today’s receivers.

Use a twist (and other popular wires) to reduce EMI/RFI. Alexander Graham Bell patented twisted pair wires in 1881. We still use them today because they work so well.

 

 

21 Things to Do: Buying your first radio

Baofeng UV-5R

This Baofeng UV-5R is made in China and costs less than $75 here in the U.S.

We all remember our first radio. I got my license back in the day when separate transmitters and receivers were more common than transceivers are today. So, my first radio was a combination of a Hammarlund HQ-101 receiver and a Heathkit DX-60B transmitter. With this combination, I was able to operate CW and AM on the 80m, 40m, 20m, 15m, and 10m bands. Of course, because I was only a Novice, I wasn’t allowed on 20m at all, and could only operate CW on the other bands.

Today, it’s more common for one’s first radio to be a VHF or VHF/UHF FM transceiver. Now that some Chinese companies have entered the amateur radio market, you can buy a handheld VHF/UHF transceiver, like the Baofeng UV-5R, shown at right, for less than $75 in the U.S. A handheld transceiver makes a good first radio, but remember that it is just your first radio. If you never buy a second (or a third or a fourth), you won’t be able to take advantage of what our great hobby offers.

The ARRL has actually done a much better job of advising new hams about buying a first radio than I can do here. So, let me point you to the ARRL Web page, “Buying Your First Radio.” On this page, there are links to several PDF files that will help you choose your first radio.

The first publication you’ll see there is the 24-page brochure, Choosing a Ham Radio. Reading this publication will get you thinking about what kind of operating you want to do, which is really the first step in choosing the right radio for you. Next, it describes features found in modern radios, and you’ll gain a good understanding of how that affects your choice of radio.

Choosing a Ham Radio also contains a lot of information about HF, or shortwave, radios. While you may start out on the VHF and UHF bands, I would encourage you to think about getting on HF, even before you upgrade to General. For me, anyway, the magic of radio is on the shortwave bands, and at the very least, you owe it to yourself to try it.

Buying Used Gear
One approach to getting your first radio is to buy used gear. In general, I would advise against doing this for your first radio. One reason not to buy a used radio is that you’re often just buying someone else’s problems, especially if you’re not in a position to evaluate the condition of a radio. Another reason is that an older radio will not have all the features and could be more difficult to operate than a newer radio.

Having said that, used equipment is not always a bad deal. You might, for example, be able to purchase an older radio from someone you trust, like your Elmer (see Chapter 1) or a fellow club member. When you purchase a radio from someone you trust, not only are you more certain that it will work properly, but you’ll have someone to go to with questions or to consult with if there are problems.

Not only that, if you ask nicely, the ham might even let you use the radio for a while before actually purchasing it. I know that I’ve lent equipment to new hams in the past. Sometimes they decide to buy the radio. Other times, they’ve decided to purchase a new radio. In either case, they were able to make their decision based on experiences they had with an actual radio.

Finally, don’t worry about making the perfect choice. First off, there’s no perfect choice, and second, you can always sell the radio and buy something else. Chances are you’ll be able to sell it for not too much less than what you paid for it, and you’ll have gained a whole lot of experience.

21 Things to Do: Set up a shack

21 Things to Do After Getting Your Amateur Radio LicenseSetting up a “shack” is an essential part of the ham radio experience. For most amateurs, their shack is a combination workshop and operating position. Another way to think about it is the place where you can go to get away from the hustle and bustle of every day life and immerse yourself in your ham radio hobby.

How did we come to use the term “radio shack”? Well, according to Rod, AC6V, the first radio shacks were found aboard ships in the early 1900s. He says, “At the time, wireless equipment aboard ships was generally housed above the bridge in a wooden structure that was called the ‘radio shack’”. For many commercial stations, the radio equipment was housed in a shack at the base of the antennas.

An early radio shack can be seen below. This is the shack of amateur radio station 8BNY circa 1922. As you can see, there’s not much in the way of amenities.

Early Radio Shack

This 1922 photo shows the "shack" of amateur radio station 8BNY.

Setting up your own shack
When you set up your own shack, there’s no need to be as ascetic as our forefathers shown above. In fact, I’d advise you to make your shack as comfortable and as convenient as possible. The reason for this is that the more comfortable and convenient it is for you, the more you’ll enjoy it, and the more you’ll want to use it.

The first thing to think about is where in your house, condo, or apartment you will be setting up your shack. Lucky hams have a spare room that they can use for their shacks. Unfortunately, most of us aren’t so lucky. Mine, for example is in my basement. The good thing about that location is that I have plenty of space. The bad thing is that it can get quite cold down there in the winter. All locations are going to have plusses and minuses, so weigh them carefully before getting started.

Richards, K8JHR, is a recently-licensed ham who has given a lot of thought to how to set up a shack. He recently wrote about his experiences and posted the article to the HamRadioHelpGroup, a Yahoo Group for hams looking for help and willing to help. I thought so much of the article, that I published it here on my blog. Here are some of the more important points:

  • Have plenty of AC outlets.
  • Buy a big desk that can accommodate lots of radios and station accessories.
  • Plan ahead for routing LOTS of wires, cables, and connectors. Think about how you’re going to run these cables into and out of your house.
  • Buy a really good, substantial, large swivel desk chair.
  • Locate your shack as close to the ground as possible.
  • Build shelf-risers that give you more vertical space.
  • Include space for bookshelves and maybe a filing cabinet.
  • Make sure your shack is well-lit.
  • Buy a big clock that shows Zulu or UTC time.
  • Get a bulletin board for displaying cool QSL cards, certificates, and for posting the odd note.

Another thing to consider when setting up your shack is how to ground your station. Ben, N2IHK, suggests reading W8JI’s Web page on ground systems (http://www.w8ji.com/ground_systems.htm). Remember, a good RF ground is not the same as the AC power ground!

Another good reference on setting up an amateur radio station is The ARRL Handbook for Radio Communications. This book includes a chapter on station layout and accessories. I’ve found that the earlier handbooks are better in this regard than the latest editions. For example, my 1986 edition of the Handbook includes diagrams on how to build an operating desk, including vertical risers. The 2005 edition does not have those plans.

A good shack will make you a better amateur radio operator. You should give it as much thought, or even more, than you give to buying your first radio.


Contest encourages hams to develop microcontroller apps

From Luc, ON4ZI via the Linked In Amateur Radio Enthusiast group:

ON6NR starts the second Ham – mbed/ARM contest

Discover top notch microcontroller. Propose and describe a Ham application using mbed board see http://mbed.org. 10 projects ( described in French) will be selected and will receive an mbed module to realize the suggested project. Appropriately documented circuits (Doc or txt), with video (uTube) and/or pictures (jpeg) to prove affective functioning send by June 30th, 2012 will be entitled for the final draw with sponsor pricing to be defined.

The contest aims at 3 objectives: 1) Help Ham fellows to discover and experiment with “top notch” 32 bit microcontrollers; 2) Make their development useful to the ham community; 3) Generate quality articles to be published in QSP Revue, the freely monthly electronic publication issued for Hams at the radioclub (5000 + downloads, plenty of mirroring)

Submissions must be sent to either on5fm@uba.be or on5fm@dommel.be no later than 24:00 (GMT) 22nd April 2012. A jury of ham operators, embedded specialists and engineers will review proposals for concept quality, possibility of realization, reproducibility, interest and usability. It will not necessarily be the most impressive proposals that will be selected, so all participants have an opportunity to win!

The mbed microcontrollers are interesting in that they are 32-bit designs in a very small form factor. The entire microcontroller, including a USB port fits on a PC board the size of a 40-pin DIP!  By contrast, the Arduinos are all eight-bit processors.

From the Trade Mags – 3/27/12

Three more articles from the electronics engineering trade magazines that ham radio operators will find interesting and useful:

  1. Understanding Modern Digital Modulation Techniques. Want to understand what’s happening when you operate PSK-31 and some of the other digital modes? Read this article.
  2. Understanding CTCSS from A to Z. This short article does a nice job of describing CTCSS, which stands for Continuous Tone Coded Squelch System. It includes a table of all the standard tone frequencies.
  3. Understanding Amplifier Operating Classes. A nice review of amplifier classes from A to H. I didn’t know that we were up to Class H already.

Winter 2012 TAPR Journal now online

The TAPR PSR Digital Journal, Winter 2012 edition, is now online (www.tapr.org/psr/psr117.pdf). Contents include:

  • President’s Corner
  • iQuadLabs-TAPR Agreement
  • 2011 DCC Video Online
  • TAPR Directors Elections
  • VK5DGR on Codec 2 at linux.conf.au 2012
  • Doodle Labs DL-435
  • Going to Ohio
  • When Digital Was Mechanical
  • Now on YouTube
  • TAPR-ARRL DCC 2011
  • HPSDR Projects
  • Frequency & Time Related Kits
  • The Great Create
  • My Steve Jobs Story
  • LW and MW DX
  • Join TAPR on Twitter & Facebook
  • Write Here!
  • PSR Advertising Rates
  • Still Fixing a Little TAPR History
  • The Fine Print
  • Our Membership App

New QRP kit measures power, SWR

From Terry, WA0ITP, via the qrp-l mailing list:

QRP-o-meterThe Four State QRP Group is pleased to announce a new kit, the QRPometer, a sensitive and accurate power/swr meter designed by David Cripe, NMØS.   Complete specifications, assembly manual, and ordering information can be found online PayPal is accepted.

The range of accurate power measurement extends down to a low 100 milliwatts.  This kit was conceived to fill a need within the hobby for an inexpensive, highly accurate RF power and VSWR meter for QRP power levels.  With it’s large digital display it makes a very useful addition to your shack.

The QRPometer uses simple analog signal-processing circuitry to provide a set of essential measurement features not previously available in a single unit. High quality, double sided, printed circuit board construction is used, with solder mask and silk screened component reference designators.

All components are  through-hole for easy assembly. NO toroids are required, and all controls  and jacks are PCB mounted. The QRPometer can be constructed by beginners as well as experienced builders. Construction time is approximately 3 hours, depending on experience level. The only equipment required for calibration is a digital voltmeter, and a QRP transmitter..

All proceeds  go to fund OzarkCon.  As always, thank you for supporting the Four State QRP Group.

TAPR starts “interest list” for Hermes SDR

From the TAPRARRL Letter, 3/22/12:

Tucson Amateur Packet Radio (TAPR) announces the opening of the “interest list” for the openHPSDR Hermes single-board Software Defined Radio. The Hermes interest list is used by TAPR to determine the number of Hermes boards to manufacture in the pending initial production run this spring. Hermes is a long-awaited addition to the openHPSDR project lineup, advancing through four prototypes while evolving from a USB-based to an Ethernet-based transceiver in about two years. Hermes is a Direct-Down-Conversion receiver, a Direct-Up-Conversion 500 mW transmitter and a gigabit Ethernet interface all on one board. Also on board is an RF-quiet switch-mode power supply, which allows Hermes to run from a single 13.8 V dc source. Read more here.

Building a New Shack?

Richards K8JHR, origninally posted this to the HamRadioHelpGroup mailing list. I thought it was so good that I asked if I could post it here. Now, if only my shack had all these features……..Dan

Here are a couple of considerations to ponder when building a new shack.

  1. HAVE PLENTY OF AC OUTLETS. Run an extra line if you can, to dedicate to just ham gear. Run a 22ov line if you think you will run a linear amp. Most can run on 110v AC, but nearly all will coast along and run cooler on 220v AC.
  2. Have a big desk top. Lots of guys use narrow desks. I have two 30″ x 72″ desk shells with some drawer units under each, and lots of leg  room under both. I would prefer a 36″ deep desk top and will do that next time. Loads of guys use counter top that is only 24 inches deep, which leaves you NO room to write or have separate notepaper or other important stuff, like you code key, a desk top PTT switch, or a mug of beer.
    Plan ahead for where you are going to put your computer – and monitor - especially if you need to locate the transceiver away from the monitor to avoid unwanted stray EMI/RFI and electrical hash some LED and plasma monitors emit.
    Plan space for computer speakers, radio speakers, and other jazz like that.
  3. Plan ahead for LOTS of wires, cables, and connectors. My desk shells are both 6 inches from the wall, leaving room for patch cables, power cables, switches, connectors, and the like.
  4. Include some heavy-duty shelves. I built shelves on the walls, above the desk, and used heavy shelf brackets, which are attached to the studs in the walls, and can hold something like 500 lbs each, and I set the shelves on the brackets, about 1.5 inches away from the wall so I can pass cables and connectors up behind the shelves to the rear of any gear I place on the shelves. This allows the wires to be hidden behind the stuff on the shelves, yet I can easily deploy the cables between the various equipment.
  5. Take notice that ham gear is often HEAVY. I see so many photos of shacks where the shelves are sagging terribly – often to a point where one might worry they might give way and fail.
  6. Plan ahead for adding more gear, and other useful stuff, like large notebooks which can hold the instruction and user manuals, copies of adverts, service manuals, and also hold copies of articles you might collect along the way. Plan space for the rather large, and heavy, ARRL Handbook, ARRL Antenna Book, and other books and guides you might purchase along the way.
  7. Buy a really good, substantial, large swivel desk chair. Don’t get one of those wimpy little secretary task chairs they sell for $69 at Staples Depot Max. When in practice, I bought my secretary a super high quality, comfortable Herman Miller desk chair. I will never understand why so many other professionals load up their secretaries with work, but buy them a crappy, cheap, uncomfortable, chair to camp on all day. These days you can get a fairly decent executive type desk chair at Staples Depot Max for between $125 and $200 - and it is worth it. Why sit anywhere for any extended time in a crappy chair? But so many hams do just that, if you see photos of their shacks, you see $10,000 in radios and related gear, but a crappy old $5 chair they got at a flea market. Dumb – take good care of yourself.
  8. Locate your shack as close to the ground as possible – both physical earth ground, like what we know as dirt, and also electrical ground, like what the electrician calls ground, so you can tie (bond) your shack ground system to the domestic electrical system ground, what is called “single point bonding.” That is a whole topic for later… but plan ahead for this.
  9. Think about whether or not you are left0handed or righ- handed… where the window is… how you are going to lay out the radios… tuner, linear amp, code key, and even where you will hang your headset or head phones, and even plan where the microphone and PTT switch will go. Lets see… 2 meter rig… HF transceiver… you operate the tuner with your left or right hand… think about this as you proceed.
  10. Build shelf-risers that give you more vertical space. I have multiple levels of gear on the desk top. This allows me more gear in a vertical space. Plan for these things as you proceed, and maybe you get some help from a handy and well-equipped neighbor or friend if you don’t have this type of shop equipment, yourself. I make all sorts of wood stuff  for the local rabble. One of the local guys has a tool and die shop, and can make me custom metal stuff, but mostly he has told me how to do stuff myself, but the point is to tap into these local resources as you develop your shack.
    I use inexpensive, but attractive materials, such as vinyl covered per-fabricated shelving boards. They come in wood-grain finishes that match the color of my desk shells. Sometimes, I make shelf risers out of pine or white wood, and then stain the wood to match the desk and shelving. This wood is inexpensive, easy to work with, and takes stain well., compared with the usual hardwoods, such as oak or maple. But you should use what works for you. The point is, to plan ahead and maximize the available space – my shelf risers pretty much double the number of radios and accessories I can put on the desk.
  11. Get the wife involved. Not only will she have good ideas on how to lay out your gear, but she may have suggestions you will not realize on your own. My wife does that and sometimes she saves me from making a short-sighted move. In any case, this will get her invested in the shack-building process, and she will be more supportive and enthusiastic about your ham shack if she has a hand in assembling it. My young bride surprised me with new curtains – she found some nice, heavy, masculine material with colors that accented the silver, black, and bronze colors you see on ham gear.
  12. Plan for good lighting. Nothing worse than working in the dark.
  13. Put a long multiple-plug-power strip on the wall behind the desk, at about, or just slightly below the height of the desk top – typically 29-30 inches up from the floor. You won’t believe how many power cables, wall warts, and etc. you need to plug in to complete the shack. Do this before installing the desk, etc.
  14. Plan for multiple antenna cables entering the house. Do this before you assemble our desk and lay out the equipment on it. Some guys use MFJ and similar window coax pass through boards – which bring coax and other antenna cables into the shack from outdoors. I don’t use them because they do not allow a way for my windows to seal in the middle when closed down on the pass through boards – but you may have different windows that admit of better security and weather sealing. Some guys use 6 or 8 inch long bulk head connectors that allow you to bring in coax leads. Others use various other means of passing cables through walls, including PVC pipe of various diameters. Be sure to use a curved coupling or two, so to allow you to make a drip loop. You want the cable to turn up, and run up for a couple of inches, before turning horizontal and coming through the wall… which allows rain to drop off the low portion of the loop, and not run into the PVC pass through. (I hope this is clear enough… hard to say in words this late at night…) Still other guys use a remotely located and remotely controlled switch, with a single coax cable into the shack, to minimize the number of cable they need to pass through the exterior wall of the house.
    In any case, the point is to PLAN AHEAD for these things, so as to minimize surprises, disappointment, and waste.
  15. Plan for a big clock that shows Zulu or UTC time. I have a smaller alarm clock on my desk, right under my computer screen, but you might like a larger clock of some kind, but in any case, plan for a separate clock for world time, as hams live on Zulu time, and not local time.
  16. Get a bulletin board or leave some space for putting up various wall paper, such as Worked All Whatever Awards, Band Plan Charts, Tuner and Amp Setting Charts, Colored US Section Map, repeater frequency charts, and photos you will surely collect over time.
  17. Include the following amenities:
    • bathroom – preferably full bath with a shower
    • walk in storage closet
    • hallway placing the shack, bathroom, and storage closet down the hall, away from the family rec room
    • refrigerator with ice maker
    • coffee maker
    • microwave oven
    • separate supply of coffee mugs, beer mugs, etc. for you and your ham friends
    • a couple of chairs for friends, wife, kids, grandkids, etc. Don’t be a hermit !
    • a lighted call sign as well as a call sign coffee mug… or two… cannot have too many of these in the shack.
    • a sufficient supply of beer, bourbon, and snacks and sundry comestibles for snacking and refreshing you and your friends as you don’t wanna be undernourished or become dehydrated during a long QSO or, especially, during a big contest…. ;-)

Scour the web for images of other ham shacks, and see which ones you like, and which you don’t, noting the reasons therefore. See what other guys are doing. You will be surprised at how many really cool shacks there are, and also how many really messy, inconvenient, awkward shacks there are. It takes all kinds, but, surely some of them will appeal to you and you will get some good ideas from doing this.

This is just MY take… your mileage may differ.