Solar cycle #25 has reached its peak and is on the decline again. We may still have a few years of good propagation left but I am planning ahead. During the last solar minimum I adapted by ... forgive me ... increasing my transmit power. This time around I hope to keep working QRP, but … Continue reading What to do when the bands suck?
Category: Builder Projects
An alternative mini-GTU design by Tim KQ4TQ
As I mentioned in the last post on Ham Radio Outside the Box, I received a surprise package in the mail from Tim KQ4TQ in Georgia. Tim sent me his build of a mini Ground Tuning Unit (GTU) that is simpler in design than the one I built. Tim's design is a single inductor of … Continue reading An alternative mini-GTU design by Tim KQ4TQ
The magic carpet ground plane is grounded, but the GTU keeps flying.
Ham Radio Outside the Box receives quite a lot of email every week from readers with questions, comments and suggestions. One such email came about as a result of an article in the outstanding newsletter from the Surrey Amateur Radio Club called the Communicator. The editor of the Communicator is Canadian Amateur Radio Hall of … Continue reading The magic carpet ground plane is grounded, but the GTU keeps flying.
A Mini Ground Tuning Unit and a magic carpet for portable ops
In the last couple of posts I discussed my quest for a simple portable antenna that could be rapidly deployed in a very limited space, for example in a small clearing while hiking through the woods. Such an antenna would have to be a short, yet efficient, vertical that occupies a very small footprint on … Continue reading A Mini Ground Tuning Unit and a magic carpet for portable ops
A Linear-Loaded Monopole antenna for hiking
There is a lot of information online about Linear-Loaded Dipoles, but I haven't found anything at all about cutting a Linear-Loaded Dipole in half to create a Linear-Loaded Monopole worked against ground. The legendary L.B. Cebik (W4RNL, SK) published a design philosophy for an 80m Linear-Loaded Monopole, but it didn't match what I had in … Continue reading A Linear-Loaded Monopole antenna for hiking
The “tootie-toosie” and the Hiking Antenna
My favorite way of operating is to hike into the woods, find a clearing, set up a quick and easy antenna, make one or more contacts and move on. Well, to be honest, I might pause long enough at a back country waypoint to get out my Aeropress and brew up a refreshing cup of … Continue reading The “tootie-toosie” and the Hiking Antenna
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
Engineering challenges of the completed QRP EFHW coupler
Kudos to Kits and Parts, the United States Postal Service and the Canada Post dog sled teams who fearlessly fought their way through blizzards on the frozen barren tundra into the wild white yonder to safely deliver my package of toroid cores. But, as soon as I had unpacked the goodies I realized I may … Continue reading Engineering challenges of the completed QRP EFHW coupler
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
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