Tag: Antennas

Experiments with portable, base station and highly unusual antennas

The CFHW – a simple, efficient HF antenna I may never use

What in Heaven's name is a "CFHW"? A CFHW is a Center-Fed Half-Wave antenna. You may know it better as a dipole and it is indeed a highly efficient simple wire antenna. I can't claim originality for the term "CFHW"; it started as a joke on one of the forums I follow. Following the trend … Continue reading The CFHW – a simple, efficient HF antenna I may never use →

A highly efficient multiband QRP L-match builder project

Here is a project that provides a much more efficient way of matching an End-Fed Half Wave antenna than the usual 49:1 impedance transformer. High ratio transformers are prone to inductance leakage, core saturation and overheating leading to low efficiency. Although a 49:1 (or similar high ratio) transformer can present a low SWR to a … Continue reading A highly efficient multiband QRP L-match builder project →

A 20-minute QRP End-Fed Half-Wave antenna coupler

It was almost time to make lunch but I had an idea that just wouldn't wait. I figured I had 20 minutes to zip down to the basement shack/development lab and throw a simple circuit together on the workbench. I had been re-reading (for the 1000th time) AA5TB's website about using a parallel tuned circuit … Continue reading A 20-minute QRP End-Fed Half-Wave antenna coupler →

Great ideas from Ham Radio Outside the Box subscribers

QRV: An interesting iOS/Mac app for hams from Adam K2CAT who writes: I developed QRV to be the ham app that I always wanted. There are a lot of great tools for amateur operators: QRZ, HamQSL solar conditions, PSKReporter, and more; they just were scattered and some are not mobile friendly. My goal was to … Continue reading Great ideas from Ham Radio Outside the Box subscribers →

This is still a hobby, isn’t it?

Ham Radio continues to change. Whether you believe the changes are good or bad depends on a lot on your perspective. But, no matter if you are a traditional brass pounder, or you believe the Internet is the future of ham radio, one question stands out as we enter another year. Is ham radio still … Continue reading This is still a hobby, isn’t it? →

A Year End Compendium of Outside the Box Antenna Ideas

We have reached the end of another year of crazy ideas here at Ham Radio Outside the Box and a repeat of last year's severe winter has gotten underway in southern Ontario. The daily temperature high remains well below freezing and the ground is buried under a thick blanket of snow already. I have tried … Continue reading A Year End Compendium of Outside the Box Antenna Ideas →

What really determines the efficiency of an antenna?

Is it Standing Wave Ratio (SWR)? It is common knowledge that when an antenna has high SWR some of our transmitted power is wasted instead of being transmitted. But is this really true? The trouble with "common knowledge" is that it spreads without further scrutiny. "It must be true because that's what everybody thinks". But … Continue reading What really determines the efficiency of an antenna? →

4:1 Balun or 4:1 Unun – how to choose?

Perhaps one of the greatest confusions in the hobby of ham radio is wrapped around the subject of baluns and ununs. What are they, where should they be used and what do they do? At Ham Radio Outside the Box several antennas that need a 4:1 impedance matching device have been described. Since I had … Continue reading 4:1 Balun or 4:1 Unun – how to choose? →

POTA PERformer radials – can we make a compromise?

There has only been one light snowfall in southern Ontario so far this season - just a few centimeters that melted away within a couple of days. In anticipation of upcoming heavier snowfalls and a semi-permanent white blanket that will last until spring, I bravely shrugged off the chilly outside air and set up my … Continue reading POTA PERformer radials – can we make a compromise? →