Monthly Archives: August 2009

Guest Post – Paul AE5JU on Anderson Powerpoles

Paul AE5JU gave a presentation to his local radio club, BEARS, at their August 12th 2009 Meeting and has offered the material as a blog post from the Wednesday presentation:

Tonight I will be showing how to install and use Anderson PowerPole connectors. These are considered “the standard” power connector for ARES/RACES and allow interconnectability of power supplies, batteries, cables, etc. If assembled correctly there is no way the user can plug something in backwards and let the magic smoke escape from his radio gear.

While some may disagree on using the PowerPoles as a standard, I think we would agree that interconnectability is a good thing, and there has to be some standard… and it might as well be PowerPoles.

This is so easy even… uh, hams can do it.

This is a page of links and other information about the items I will be talking about tonight. Consider this email my “handouts” for the presentation.

Buy Anderson PowerPoles and related items at

Anderson Powerpoles

The 30 Amp type will interchange with 15 and 45 amp types. I suggest buying the 30 amp type to cover most of your needs.

On the West Mountain page you can also order red/black zip cord in various gauges.

How to install PowerPoles: (scroll down to find the PowerPole Connector General Installation Tips)

Ready made cables/adapters

West Mountain Radio Rigrunner Power Strips
Note, you can buy the Rigrunner Power Strips alone, or with pkg of PowerPoles

Crimper for 15/20/45 amp Powerpoles

This is the most expensive ones are 39.99, but this one does a fine job on the 15 and 30 amp sizes for just $12.99 $15.99 (updated price as of Dec 22nd, 2012): (Updated URL as of Dec 22nd, 2012)

Other power cables and plugs for many ham radios:

For example, the plugs on top left, top right on that page fit many common 2 meter/mobile rigs.

The cable on the bottom left column fits both my Yaesu FT-897 and Icom 718.

Paul – AE5JU

Paul demonstrated installation of PowerPoles including his crimp, solder and heatshrink enhanced application.

Hope that these notes and links are of use in your work with PowerPoles.



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Software Defined Radio (SDR) goes HT

Software Defined Radio (SDR) goes HT, albeit for the Government:

Over a year ago:

Thales Communications announced its Liberty™ Multiband Land Mobile Radio (LMR), the first multiband, software-defined LMR for government agencies and first responders. With coverage across all of the public safety bands (136-174 MHz, 380-520 MHz, 700 MHz, and 800 MHz), Federal, State, Local, and U.S. Department of Defense agencies can now communicate using a single portable radio that operates in direct mode or uses existing infrastructure in any of the bands.

The first multiband LMR to be put in the hands of users, the Liberty radio is currently undergoing operational evaluation and is in use by multiple public service agencies in large major metropolitan areas, by statewide public service agencies, and at federal labs. It has also been in service at the Presidential Inauguration, Academy Awards, and several live burns.

Understand that the deployment units are now out there and in extensive trials.



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Making it All Add Up – Don’t Depend on a Calculator

Don’t Depend on a Calculator

(A slightly different version of my article has appeared in my other blogs & writings)

One of the great weakness that is an unintended consequence of computing technology is the reliance on Computers and Calculators to do our basic math.

Given a series of calculations it isn’t uncommon to see someone type them into Google if at their computer, or pound out the most basic math on a Calculator.

So dependent are many of us that we fail to recognize an entry error or a formula error’s wildly incorrect result. Why? Without having a mental concept of the math we have no clue what the result should be.

There is an alternative to this dependency on fragile “black box” electronic math aids that would serve us well in a time of need.

Several times I have seen simple back-up charts save the day.

In the early 1980s on a Field Artillery range in Europe a newly introduced targeting computer was not giving the results needed. Whether the machine was at fault or the training had lead to operational errors mattered less than that it simply was not possible to use the system to put down fire where ordered.

The crew had all but given up when a Warrant Officer walked over, surveyed the situation, left only to reappear with a Wizard Wheel device that he had saved from his early career. The Wizard Wheel effectively replaced the fancy black box’s failed math with solid predetermined usable math.

Ten years later while working with medium cranes an instructor at a large safety seminar illustrated a precise set of formula to size the cribbing needed under a crane’s outriggers to support the device in operation.

During a break the presenter mentioned that the complex math, a series of complex calculation that were seldom properly worked out in the field. These field math errors had resulted in losses of equipment and life.

With literally a “back of napkin” set of calculations I was able to show him how to skip all the complex math and arrive at a simple logic tree with single simple math function that would approximate the cribbing size with a 2 to 6% additional safety factor. Instead of the risk of asking an operator to do six- to-seven math calculations without error, the operator had to make the same simple soil evaluation and pick a set multiplier for a single decision, soil type, to apply in order to get a one-step result.

The three principles of independence from Machine Calculations I have been alluding to are:

  1. Doing Mental Math
  2. Using a Nomographic Aid, like a Wizard Wheel, where the math is basically charted out ahead.
  3. Reducing the Math from overly complex and needlessly over precise to simple rules of thumb calculations, a sort of math heuristics.

A quick pro & cons of each technique:

Doing Mental Math

Doing Mental Math should be part & parcel of every math calculation you every do, specially if it affects someone’s well-being. As a family we drill on mental math as a challenge, from the simple to complex ideas like magic numbers (a special form of prime numbers). We do this to work at maintaining mental agility, to be comfortable competitive, and to prepare our children by being able to recognize when “black box” solutions give the wrong answers.

At a minimum doing a quick Mental Calculation will help “bracket” a computerized calculation. I stress that you have to know roughly what a calculation will return to be able to judge if the result appears sensible.

The downside to spending a lot of time on Mental Math is basically not letting it become a distraction from the core tasks at hand. If doing mental math personally reduces your situational awareness significantly, you may have to triage mental math in favor of situational safety.

Using a Nomographic Aid

Confession time – I love Nomograms. A Nomographic Aid is a mechanical device that by rote develops the answer for a calculation from the raw inputs. Some that a reader may be familiar with, or at least have seen in action are Slide Rules, a pilot’s E6B Flight Computer, or a tradesman’s Wizard -Wheel of some type.

What a Nomographic Aid does is to allow a person to “set up” the calculations inputs and directly read the result. “The Math is Hard Coded” in the device.

On the plus side a Nomographic Aid can help you quickly get results, specially when the actual calculations would be labor intensive to do longhand.

On the downside you have to trust that the Aid was done right, perhaps applying some Mental Math to the situation. Additionally some Nomographic Aids are not intuitive and require training or practice to safely use.

Reducing the Math to simple Rules of Thumb

Don’t do a whole series of calculations, with a result giving a level of unusable precision, when a simple Rule of Thumb could give you workable results in a single step. In my example above, there was no need to calculate the surface area of crane cribbing to the square inch when doing so added huge risks of error, and the field materials never provide for such fine precision.

By carefully developing “quick math” Rules of Thumb it is possible to reduce the risk of errors and speed up unaided calculation time.

Of course a Rule of Thumb is only suited to repetitive calculations as it is developed from experience gained from working with a known condition.

There is a level of risk if the Rule of Thumb contains an error, or it it applies to only a limited range of values. It is also important to understand what the full calculation includes to be able to do some Mental Calculations to back-check the Rule of Thumb. A Rule of Thumb calculation also usually incorporates a higher safety margin than full calculations could give, which may be an important consideration in a situation of limited resources or improvisation.


Making Math Simple reduces risk of calculation errors, reduces our dependence on machine calculations and is immensely satisfying to the individual. Where possible do the math in your head, use a calculation aid, and look for simple Rules of Thumb. Practice enough mental math to be able to recognize whether assisted calculations are giving results “in the ball park.” Use a slide-rule, wizard wheel or nomogram graph when available. Cut past all the “roughage” and recognize that there often is a simple Rule of Thumb you can use.

Direct Application to Amateur Radio

One of my friends, George W9EVT, has a killer shack with perhaps a half dozen computers driving various parts of the shack, yet has fantastic laminated sheets of bearings to national and world wide locations.  The sheets let him “back check” the calculated suggestions for bearings and operate independently of assistance if desired.

This sort of handy charting-in-advance pays dividends when working DX or even county hunting.

A similar exercise for RF Exposure should be part of most every station’s paperwork. Simple Nomographic Charts worked out for the station’s particular configuration.

Hope you find ways to make Mental Math, Nomographic Aids and Rules of Thumb work in your shack.



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“Go to the Well” – Look to Primary Sources of Radio Help

How often to read in some forum about station XYZ’s problem with device ABC, usually with a strong negative opinion following?

Read further and often you find they have NEVER contacted the manufacturer.  Really, they never asked the people who built the equipment!

They never went to the primary source for help!


Many say it is to “preserve the right to complain.”  For some amateurs that seems to be much the case.

Some don’t want to be caught “reading the directions” and feel that asking the builder is some sort of defeat.

Others simply are so accustomed to working things out, that they simply have forgotten to go to a primary source.

And of course in many instances with older or less common gear, the builder may be defunct, gone, SK or otherwise unavailable.  Sometimes there is an obvious successor or expert resource, but in some cases it simply isn’t obvious to who a person would look to for product support.

There also was a day when support costed.  Not too many years back several transceiver manufacturers charged significantly for reprints of user manuals, for service manuals and for support documentation.  For the most part these things are now available on the web at low or no cost, but a few holdouts are out there.

Before posting questions to forums, using up Radio Net time or bringing up a question at a club meeting, I’ve learned to do at least some basic research.  Sometimes I find the answer right away, sometimes in more in depth research, but most of all I learn enough to phase the question precisely, which helps those helping me.



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American Preppers Radio Net

The American Preppers Network “Ham Radio Net” calling CQ CQ CQ….

“Here we go folks it’s Thursday and once again it’s time to crank up the RF and take to the air with the AMERICAN PREPPERS RADIO NET.
We hope you will come join us once again for the 20 meter net. We will be throwing our voices out over the air at 9 pm EST on or around 14.320 +/_ a bit to find a clear frequency. Lots of fun and remember everyone is welcome on our nets, so tell all your friends to come join us as well. 

W4DMH Dave will be net control tonight and for those that have not heard he is sometimes called Santa even over the AIR”

Brainchild of Dave W4DMH & Bob KI4HEE the net is currently meeting at 14.320 (20m band) at 9pm Eastern Time.



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The Radio Amateur is – The Amateur’s Code

The Amateur’s Code

The Radio Amateur is

CONSIDERATE…never knowingly operates in such a way as to lessen the pleasure of others.

LOYAL…offers loyalty, encouragement and support to other amateurs, local clubs, and the American Radio Relay League, through which Amateur Radio in the United States is represented nationally and internationally.

PROGRESSIVE…with knowledge abreast of science, a well-built and efficient station and operation above reproach.

FRIENDLY…slow and patient operating when requested; friendly advice and counsel to the beginner; kindly assistance, cooperation and consideration for the interests of others. These are the hallmarks of the amateur spirit.

BALANCED…radio is an avocation, never interfering with duties owed to family, job, school or community.

PATRIOTIC…station and skill always ready for service to country and community.

The original Amateur’s Code was written by Paul M. Segal, W9EEA, in 1928.