8 May 2010

TriBand J-Pole Antenna Plans

Newly licensed Hams, as well as those on a budget, are always looking for a simple, inexpensive antenna for two meters and 440 MHz. After trying several designs over the years, I finally constructed one from these plans. It works very well and required no adjustments for acceptable SWR!

One addition, if you solder a cap on the lower 37.5" piece of copper tubing, make sure to provide a condensation drain hole near the bottom of the antenna.    de Glenn - K5GC

TriBand (2m-220-440) J-Pole Plans (Right Click To Download)

20 April 2010

New MIC - NWS San Angelo

Dr. Steve Lyons has accepted a position with the National Weather Service as the Meteorologist-in-Charge of the San Angelo, Texas office. Dr. Lyons spent the past 12 years working for The Weather Channel® as a tropical weather analyst. Prior to that, he served with the NWS at the National Hurricane Center (NHC) in Miami, Florida.

Dr. Lyons fills the position formerly held by Buddy McIntyre, who retired in March.

San Angelo newspaper article

15 February 2010

Garmin GPS: Year 2010 bug

Garmin GPS: Year 2010 bug - possible pitfall for APRS Ops. This might be interesting to all GPS users - especially APRS operators. There seems to be a year 2010 bug with some Garmin devices.     QRZ Forum

When switching on, date and time are calculated wrong. But making it even worse, almanac data is also lost, so it needs to search for all satellites whenever it is turned on (cold boot).

Garmin Newsgroup
Model Specific Info

15 February 2010

GPS might be set for problems from the Sun

Researchers say the Sun is awakening after a period of low activity, which does not bode well for a world ever more dependent on satellite navigation.

The Sun's irregular activity can wreak havoc with the weak sat-nav signals we use. The last time the Sun reached a peak in activity, satellite navigation was barely a consumer product. But the Sun is on its way to another solar maximum, which could generate large and unpredictable sat-nav errors.

The satellite navigation concept is embodied currently by the US GPS system and Russia's Glonass network, with contenders to come in the form of Europe's Galileo constellation and China's Compass system. It depends on what is - at its root - a simple triangulation calculation.

A fleet of satellites circling the Earth are constantly beaming a radio signal with two bits of exceptionally precise information: where exactly they are, and at exactly what time. A sat-nav receiver on Earth - or on a ship or plane - is equipped with a fairly precise clock and the means to collect signals from the satellites that happen to be in its line of sight. It then works out, based on how long it took those signals to arrive, how far it is from each of those satellites. Some simple geometry yields its position.

• 1. Satellites advertise their exact position, and the precise time at which they are sending it.

• 2. The signal travels through the outer atmosphere, the ionosphere; its speed depends on how much the Sun's radiation and particle winds are affecting the ionosphere's composition.

• 3. A receiver on Earth determines how long the signals took to arrive from a number of satellites, calculating the position from the time differences.

QRZ Forum Article