Small Loop HF Antenna

With components from a variety of vendors, custom machining and a bit of trial and error, another variant of a small loop HF antenna is born.

KX4O 1B-Battery VA Field Day 2015

The 20m AHVD and 40m small loop antennas during KX4O 1B VA field day.

Despite a weak battery and few contacts, our 1B-Battery effort verifies a 40m small-loop and packet-radio NTS messaging using quick deploy antennas.

40m Mastless NVIS Antenna

Yet another 40m Cloud Burner design featuring a folded dipole driven element plus one reflector wire to facilitate 40m NVIS contacts without need of a tall mast. The design uses electric fence posts for support and needs no balun.

EFHW LNR Precision EF-10/20/40MKII Test Data

SWR Measurements of LNR Precision EF-10/20/40 End Fed Antenna

Basic tests of the LNR Precision EF-10/20/40 multi-band portable HF EFHW antenna including S11, SWR and a bandwidth check of the match box.

EFHW LNR Precision EF-10/20/40MKII Examination

The background and details of the LNR (Par Electronics) EF-10/20/40 end fed half-wave multi-band portable HF antenna. Come see what’s inside the mysterious “black box.”

Ladder Line the Old Fashioned Way

A fellow club member is preparing to put up a big 160 meter horizontal loop antenna. Nice. We have discussed many options and conclude ladder line is the best approach to connect the loop to the operating point.

He went shopping online only to find many vendors are low in stock of many items including the 400ish ohm windowed ladder line. We both agree making our own is a viable option.

So here is a photographic step by step we took in 2005 to construct the spreaders of our ladder line fed dipole antenna we use for Field Days, JOTA and other events requiring a simple antenna.

Since our antenna is used for various events it is not in the weather long. We opted to use wood spaces soaked in paraffin.

Read moreLadder Line the Old Fashioned Way

43 Foot Antenna Installation – The Rising

Here are some details regarding the next, and probably last, phase of my 43 Foot DX Engineering vertical installation.

This post is very late. The actual date of the events within it are just before March 2009 in preparation for the Virginia QSO Party.

In the many posts within this site, it is no secret my examination of various vertical antenna solutions with comparison between BigIR and the 43 Foot products a big part of this. Check out all the 43 Foot posts on HHD here…

Read more43 Foot Antenna Installation – The Rising

NVIS 80m with 160m Full Wave Loop is less than ideal

As my local club in northern Virginia prepares for the March Virginia QSO Party many questions are asked about how best to take full advantage of Near Vertical Incident Skywave (NVIS) communications so critical to maximizing contacts on HF within the state.

In particular one member has a magnificent full wave 160 meter loop up around 50 feet or so. He is contemplating using it for NVIS on 80 meters. He desires to lower it to about 15 feet to improve the NVIS characteristics.

It is true lowering a dipole will focus more energy straight up while reducing the energy towards the horizon. This is a tried and true technique on 80 and sometimes 40 meter NVIS and offers a potential added benefit of less sensitivity to far away thunderstorm noise. This is a method of diminishing returns; Lowering the antenna favors the sky more, but the overall gain is reduced. In other words, less signal is focused in a better NVIS favoring pattern.

Full wave loops are quite different as this EZNEC simulation suggests. Here is a simple four sided loop with 128 foot sides and fed near one corner – just like my friend’s 160 meter loop.

Read moreNVIS 80m with 160m Full Wave Loop is less than ideal

The 43 foot vertical – The answer to everything?

The 43 foot vertical antenna is a popular height being promoted by several antenna manufacturers for 160 to 10 meters. Let’s see why and examine some advantages and pitfalls.