Showing posts from December, 2012

Project: PAiA P60 Regulated Power Supply Kit

Over the  years, we have built a number of electronic devices that require a 9v DC power source.  We typically keep a box of 9v batteries on-hand though more often then not we find our cache of batteries depleted.  During a recent trip to the local grocery store we were shocked to see name-brand 9v alkaline batteries selling for nearly $5/each.  This inspired us to build a dedicated 9v power supply for use on the bench with goal of reducing our use of overly expensive 9v batteries in the coming year.  Perhaps that is a worthy New Year resolution for us all.

Regulated or unregulated?
An unregulated DC output power supply (e.g. most common wall-warts) delivers voltage without voltage control.  The DC output voltage is dependent on a couple of factors: 1) the voltage reduction transformer; 2) the amount of current used by the device receiving the power (also called load).  An easy way to identify if a wall-wart is unregulated is to simply measure the voltage without a load.  If the voltag…

The Passing of the Year by Robert Service

The Passing of the Year By Robert Service, RHYMES OF A ROLLING STONE, 1912 My glass is filled, my pipe is lit,
My den is all a cosy glow;
And snug before the fire I sit,
And wait to feel the old year go.
I dedicate to solemn thought
Amid my too-unthinking days,
This sober moment, sadly fraught
With much of blame, with little praise.

Old Year! upon the Stage of Time
You stand to bow your last adieu;
A moment, and the prompter's chime
Will ring the curtain down on you.
Your mien is sad, your step is slow;
You falter as a Sage in pain;
Yet turn, Old Year, before you go,
And face your audience again.

That sphinx-like face, remote, austere,
Let us all read, whate'er the cost:
O Maiden! why that bitter tear?
Is it for dear one you have lost?
Is it for fond illusion gone?
For trusted lover proved untrue?
O sweet girl-face, so sad, so wan
What hath the Old Year meant to you?

And you, O neighbour on my right
So sleek, so prosperously clad!
What see you in that aged wight
That ma…

Project: Anderson Powerpole Polarity Checker

Ward Silver's (N0AX) article, "Hands-On Radio: Experiment #120: Power Polarity Protection", in the January 2013 issue of QST included a circuit diagram for a 12v polarity checker.  Inspired by the diagram, we headed to workshop on a Friday evening to fire up the soldering iron and fabricate our own Anderson PowerPole polarity checker using junk-box parts.

We are big fans of Anderson PowerPole connectors and recabled our radio gear with the connector sometime ago.  A polarity checker would be a very useful item to have around the shack and in a go-kit.
Step 0: Round up the parts and tools A well-stocked junk box and workshop will likely yield all the necessary parts needed to build the polarity checker.  A few minutes of scrounging around our workshop is all it took to find the parts for this project.
Green LEDRed LED1k Ohm resistor 1/4WPair of Anderson PowerPole connectorsJunk box plastic part to turn into an end-capHot glue gunSoldering ironShrink wrap tubing (small di…

Learning Morse Code Online

We have been thinking about Morse code and how to approach learning it.  There is interest in our local Boy Scout troop to learn Morse code in pursuit of the new Morse Code Interpreter's Strip.

We recently discovered an interesting website to help people learn Morse code online called Learn CW Online.

One of the attractive aspects of this site is that all lessons are accessed via a web browser without requiring a download or installing software.  A complete Koch CW course is available on the site via the browser - for FREE.

The Koch method is a popular teaching method and named after the German psychologist Ludwig Koch.  The Koch method teaches at the full target speed from the outset, first with just two characters (K and M).  Once a student has mastered the first two characters by being able to copy at 90% accuracy, an additional character (letter, number, or prosign) is added, and so on until the complete character set is mastered.

We really like how the CW course is organized …

DX Technique: Taking A Break = Opportunity For A Modest Station

Working DX with a modest station or QRP (5w of power or less) is an interesting and challenging endeavour.  DX'ers regularly experience having more powerful stations with 1500W amplifiers, impressive towers, and beam antennas punch through to the target station and block the lower-power stations.  To succeed, low-power stations must use skill - brains over brawn.

Here we share a useful technique to help log that DX station when operating with low-power.  This is the scenario, the DX station announces that he must take a break (i.e. take a phone call, dog needs to go out, bathroom visit, refill coffee cup, grab a snack, answer the door, ...) and will be return. 

This represents an opportunity for the savvy lower-power station since this announcement will cause the pile-up size to immediately diminish.  Time (and human nature) is on your side since the longer the DX station is off-the-air the fewer people will stay tuned to the frequency.  Why?
As soon as the station stops calling, …


It is a paradox of modern life that pseudoscience thrives amidst accelerating scientific knowledge, widespread literacy, and powerful teacher's unions.  As you are reading this, The-End-Is-Near-Nuts-V2012 are now licking their collective wounds that resulted from the world having not come to an end on December 21, 2012. Their great disappointment in our continued existence is a small source of pleasure for many of us (as well as a few good jokes on late-night shows).

As with the prior versions of The-End-Is-Near, the pattern will be for the spokesmen to make a few irrational-rationalizations explaining away their error.  Then some charismatic will start afresh with a new version of a peculiar brand of nonsense which will inevitably find a strong market with the media and a few true believers.

In the meantime, have a happy (and rational) New Year.



© Michael W. Maher and NJ2X.COM, 2012. Unauthorized use and/or duplication of this material without express and written permiss…

DXCC Completed!

We are celebrating in the shack today on completing the requirements to earn the ARRL DX Century Club (DXCC) award. The DXCC award is a worthy challenge. To earn the ARRL DXCC award a ham must confirm 100 contacts each from a qualifying different DX entity. These entitities are defined in the DXCC list. To qualify, an entity must have some definable political or geographical distinctiveness.

ARRL DXCC Information
Proof of a confirmed contact can be either a paper QSL card or a Logbook of the World (LoTW) QSL.  We are a big fan of the ARRL's LoTW so for an extra challenge we decided to we would confirm 100% of our qualifying DXCC contacts via the LoTW (and not use any paper QSL card confirmations).  This proved to be more of a challenge than we anticipated since we had to complete several contacts with many DX entities before locating a LoTW subscriber.

We also decided to make all of our contacts using transmitter power of 100W or less and with a simple wire antenna.  This mea…

Edwin Howard Armstrong's Birthday December 18, 1890

The great American inventor and electrical engineer, Edwin Howard Armstrong was born this day - December 18, 1890.  Armstrong held 42 patents and invented the frequency modulation (FM) radio, hyterodyne radio, superheterodyne radio, and regengerative radio receiver.

Shortwave Program: WTWW 9480 KHz QSO Radio Show

Found an interesting shortwave broadcast today on 9480 KHz on WTWW in Tennessee, USA called, QSO Radio Show with Ted Randall.

The program was amateur radio oriented with an guest interview discussing 6 meters.  This was an excellent program.  This broadcast was ending at 21:00 UTC on 12/8/2012.

If you are looking for interesting shortwave programming in English then be sure to checkout 9480 Khz for QSO Radio Show with Ted Randall.

Good DX and 73, NJ2X