Hiking, Hams and Hills – Station #6 of the AT Golden Packet

Virginia hikers and hams supported the White Rock Cliffs (Station #6) of the first Annual Golden Packet Event.

Summarized, we were trying to set up APRS relay stations up and down the east coast to cover and service all points along the Appalachian Trail and surrounding areas. Some RF link analysis was performed and is available for viewing at AT_Golden_Packet_Event using the remarkable Radio Mobile program and A LOT of SRTM elevation data.

Of the fourteen stations planned several points were accessible only by foot. The White Rock Cliffs station was no exception.

Read moreHiking, Hams and Hills – Station #6 of the AT Golden Packet

5/8 Wave J-Pole vs. 1/2 Wave J-Pole EZNEC Shootout

Type “J-Pole” into any search engine and you will see dozens if not hundreds of plans to build your very own J-Pole antenna. Many are variations on the tried and true 1/2 wave design with the 1/4 wave stub at the bottom. Be it a plumber’s delight with copper pipe or ladder line heaven using a trimmed up 450 ohm feed line, many folks have successfully created their own J-Pole antenna with a surprising variety of materials.

However, there appears to be some kind of mystical attraction to the 5/8 wave radiator. Several of the J-Pole designs attempt to make the radiator 5/8 wave in length and adjust the phasing stub to make for a good match.

Let’s compare the two approaches using the models available from the late Larry Cebik’s NEC collection. Here are the contenders each using 3/8 inch diameter copper pipe…

Read more5/8 Wave J-Pole vs. 1/2 Wave J-Pole EZNEC Shootout

Collinear 5/8 wave J-Pole vs. Collinear 1/2 wave J-Pole EZNEC Shootout

While planning for a ham radio hike into the mountains to support the Appalachian Trail Golden Packet exercise, I asked my club members for ideas about a good portable 2 meter antenna.

One response included a link to this web page showcasing a collinear J-Pole antenna using two 5/8ths wave antenna elements.

Read moreCollinear 5/8 wave J-Pole vs. Collinear 1/2 wave J-Pole EZNEC Shootout

2 Meter, 5/4 Wave Antenna Revealed

In a previous post we debunked the 2 meter 5/4 wave antenna as actually an end-fed full-wave antenna resulting in a poor radiation pattern hardly optimal for terrestrial use. The fix was to turn it into a collinear with the addition of a 180 degree phased stub between the two half-wave sections.

Thus, the 2 meter 5/4 wave antenna is bunk… or is it?

Read more2 Meter, 5/4 Wave Antenna Revealed

1/2 Wave vs. 5/4 Wave VHF EZNEC Shootout

A friend of mine is preparing for the upcoming Virginia QSO Party in March 2009. Part of the preparations include a focus on some good VHF antennas to support the heavy use of VHF mobile operations in this party. Vertical polarization is key to success. He spoke of a 5/4 Wave Antenna.

Unfortunately, one web site promoting a 5/4 wave antenna solution failed to realize you can’t make an antenna longer without eventually hitting a limit.

Read more1/2 Wave vs. 5/4 Wave VHF EZNEC Shootout

1/4 Wave Monopole vs. 1/2 Wave J-Pole EZNEC Shootout

J-pole antennas are an interesting solution to the goal of more gain with a simple antenna. I won’t go into the specifics of what a J-pole is as there are plenty of sites on the Internet with good plans to help you build your own.

However, there seems to be much hype about j-poles that make some folks think they have some kind of magical antenna properties. Indeed many folks report staggering improvements over their previous antennas. Is all the hype warranted?

Read more1/4 Wave Monopole vs. 1/2 Wave J-Pole EZNEC Shootout