March 30, 2013

The Altoid tin: a nearly perfect DIY enclosure

The Altoids tin is one of the very favorite enclosures of the DIY / home-brewing electronic enthusiast / ham radio experimenter.  For small electronic projects, the Altoids tin is nearly a perfect fit for purpose.

    Photograph of an Altoids tin at an oblique angle
    Altoids Tin
    Photograph by Michael W. Maher
  • Free (after you eat the excellent peppermints)
  • Recycled / reused
  • Durable (its metal)
  • Hinged lid
  • Light weight
  • Size can accommodate a small circuit board, 9v battery, and mounting jacks, knobs, and such. 
  • Outside dimensions:
    • 3-13/16" (9.68 cm) length
    • 2-7/16" (6.19 cm) width
    • 3/4" (1.91 cm) height
Happy home-brewing!

Good DX and 73, NJ2X

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© Michael W. Maher and NJ2X.COM, 2013. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Michael W. Maher and NJ2X.COM with appropriate and specific direction to the original content.

March 29, 2013

March 24, 2013

So where can I find the FCC amateur radio exam question pool?

One of the common questions people have is about how to locate a copy of the FCC amateur radio exam question pool.  The question pools (both questions and answers) are readily available for download on the ARRL website. 

ARRL FCC Amateur Radio Exam Question Pools


Dive into the FCC amateur radio exam question pool

March 22, 2013

Solder Smoke Night March 2013

This past week NJ2X and KC2VSR attended the "Solder Smoke Night" held by our local club Skyview Amateur Radio Society.  What can be more fun than building a kit?  Building a kit with room full of friends - that is what.

NJ2X's build of a dual voltage linear power supply


KC2VSR built this neat Velleman Water Alarm

KC2VSR's build of the Velleman Water Alarm kit
KC2VSR discovered the kit was a little more involved than expected since a hacksaw was required to cut the circuit board into two parts.  One part for the detector circuit and the other for use as the remote sensor.  Fortunately, the club's workshop was well equipped with both a hacksaw and vice to hold the board secure.  With a little help from a fellow ham a perfect cut was quickly made.

While experimenting with the completed circuit, KC2VSR found that his water alarm kit could be triggered by simply placing a finger across the sensor plates (without water).  With just a touch, he then demonstrated that it doubled nicely as a Morse code practice oscillator.  Fun!


Good DX and 73, NJ2X



© Michael W. Maher and NJ2X.COM, 2013. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Michael W. Maher and NJ2X.COM with appropriate and specific direction to the original content.

March 19, 2013

The Ham Whisperer: Morse Code Course

I recently learned of the The Ham Whisperer: Morse Code Course: lessons for the International Morse Code Course.  This free course is a fun way to learn Morse code.

Morse Code with a straight key is fun!

I really enjoyed lesson one.  The video pace was slow enough that I could keep up without issue and fast enough that I didn't lose interest.  I particularly liked the positive reinforcement of the association between the letter and the Morse code equivalent.  For example, while learning the letter "E" a voice would speak the letter "E" after the Morse code "dit" while the screen displayed a large, "E".  This approach worked for me very well.

The duration of the lesson was also about right with enough practice to learn three letters while short enough to again keep the student's attention.

So if you are looking for help to learn Morse code do check out The Ham Whisperer.


Good DX and 73, NJ2X

March 16, 2013

Ohm's Birthday

Georg Simon Ohm was born on this day, March 16, 1789.  Ohm was the dicoverer of Ohm's Law (E = I * R).

Georg Simon Ohm

March 2, 2013

Project: Wheel Of Fortune Kit (Velleman)

We are big fans of the Velleman mini kits.  They are low-cost, fun to build, and fun to play with.  At the same time they help kids learn valuable lessons for themselves:
  • Soldering technique
  • Discrete electronic component identification
  • Learning how to properly orient parts on a circuit board
  • Problem solving (when things go wrong)
This month, KC2VSR built the Velleman, "Wheel Of Fortune" kit.  Once built, this circuit simulates a spinning wheel.  A button is pushed to "start the wheel" causing an LED to light up randomly momentarily.  The lit LED then appears to move around and around as each LED lights momentarily in succession.  The spinning effect starts off fast and then slows with time much like a real wheel until stopping on one of the LED's.

Velleman Wheel Of Fortune Kit Package
As with our other favorite kits, there is something special about LED's - adds a real "fun factor".  The kit components are all through-the-hole type (i.e. no surface mount components).  This is really an important factor when selecting a kit for beginners.  Through-the-hole components are largers and easier to handle and more forgiving when soldering than the surface-mount type.  Stick to kits with through-the-hole for beginners.

Velleman Wheel Of Fortune Kit Parts
KC2VSR won this really great "third hand" at the Skyview Radio Society annual banquet this past January.  This build gave us the chance to try it out.  It was a perfect helper for this kit.  The built-in magnifying lens helped with seeing the small parts during placement and soldering.


Kit being soldered as viewed through magnifying glass

The "third hand" with magnifying glass really help with build process


Velleman Wheel Of Fortune Kit Built
The build turned out perfectly and was great fun giving it a spin.  Check out this short video to see the full "spin" effect.


We highly recommend the Velleman, "Wheel of Fortune" kit for a young person (or anyone else) interested in electronics and building simple fun circuits.


Good DX and 73, NJ2X


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© Michael W. Maher and NJ2X.COM, 2013. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Michael W. Maher and NJ2X.COM with appropriate and specific direction to the original content.

March 1, 2013

Falck Claroceptor 1929 AC Noise Line Filter

We found this ad quite interesting.  Apparently there were there were AC line noise problems that created a need for filtering devices back in 1929.  The more things change the more they stay the same (plus ça change, plus c'est la même chose. Plus c'est la même chose, plus ça change).

1929 Falck Claroceptor Ad
Good DX and 73, NJ2X