Archive for July, 2008

Long HT Antennas May Harm HT Radios

If you are like many recently licensed Amateur Radio operators your first purchase may well be a good Icom, Kenwood, Yaesu or other brand Handy-Talkie or HT two way radio. These are most frequently for the 2 meter and 70 centi-meter bands (144 and 440 MHz).

The antenna that comes with your radio is probably about 8 inches long and is a compromise between convenient length and performance.
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Unruly Tube Amplifiers

For those of you preparing to take the plunge into QRO power for your ham shack, you are advised to take an hour and read this web site…

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Beware the whacker

Are you new to ham radio? Welcome. There are many facets of this hobby which are technically progressive, rewarding and, yes, sometimes, I repeat sometimes, helpful. Then there are other times…
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JL Logger – Logger for Java Run Time Environment

I guess it was only a matter of time before Java made its way into the world of ham radio. Really, Java has been at the forefront of computing for some time. Whenever a programmer friend asks me if they should port their popular program to Java I say “why bother, Java is just too slow.” That was then and this is now.

Java is still slower than directly compiled programs, but computers are so fantastically fast these days, this issue is becoming not an issue.

One of the participants on the Sunday Night Tech Net mentioned he is reviewing and modifying a new, too him anyway, JAVA based contest logger.

Enter JL Logger…
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Johnson Match Box works well at Field Day 2008

At Field Day 2008 our primary Phone station used a 135 foot ladder fed dipole as the primary antenna. The ladder line is home brew with wood spacers putting the parallel 14AWG wire about 5 inches apart.

For years I have used a home brew fully balanced matcher of a design found on the Internet. However, the results have been less than what I would expect.

A club member mentioned he had available a big Johnson Match Box. I said please bring it. Here it is on our operating table with the antenna feed connected.
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APC UPS Compatible with Honda EU2000

During our Field Day 2008, we experimented with many power options. Since it is a well known fact many UPS devices are not compatible with the power generated by certain generators, we will report the combinations that work.
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Why QSO Contest Logging and Paper don’t mix

Field Day 2008 was great for us. Our wide area wireless network worked pretty well and every station could monitor progress of the whole group.

This year we extensively used the “operator initials” field in the N3FJP Field Day Network 2.8 logging software package. Operators used their call-sign as their ‘initials’ while honored guests used their actual initials.

The site-wide log offered many great analysis possibilities. One particularly interesting metric we tracked this year was QSO rates. We generated graphs of QSO totals vs. Time Between QSOs. Here is an example of the entire log…
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Ugly World of Generator Power

It is well known many models of UPS units do not like the power from motor power portable generators. Indeed it is a difficult task to keep the sine wave pristine when you don’t have the benefit of hundreds of square miles of the power network feeding you an almost infinite about of energy. Here is an example of the waveform from a truck mounted generator delivering much less power than its rated output… about 100 watts from a 5,000 watt generator.
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Fuel Cap on Honda EU2000 Will Shut Off Generator

The manual for the Honda EU2000 clearly states this, but you need to be sure you adjust that little circular knob on the Fuel Cap to the operating position or the generator will certainly quit after a few minutes operation.

Fuel cap with knob on Honda EU2000 Generator

Fuel cap with knob on Honda EU2000 Generator

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Outdoor Yard Lighting Attracts Lightning

Well not really attracts lightning, but certainly allows for more pickup of lightning energy.

Last night on our Sunday Night Tech Net (Fauquier County, VA Repeater) a fellow named Bob brought up the topic of proper grounding for his upcoming coax fed 40 meter antenna. During the discussion about common ground points and other relating lightning protection possibilities, he recalled a story.
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