Fred C (W6BSD)
Info This article was also posted in French on my club's website F6KOP The objective of a choke balun is to reduce RF current flowing on the outside of the coaxial cable, thereby improving the symmetry of the radiation pattern and suppressing radio-frequency interference (RFI). The target values...
Fred C (W6BSD)
Stop Guessing and Start Whispering! I recently moved to a new house and had to rebuild my antenna setup from scratch. Like most people, I checked the SWR to make sure my radio was working well, but a good SWR only tells part of the story. It doesn’t show where your signal actually goes after it...
Fred C (W6BSD)
Introduction VHF and UHF1 bands form an essential part of the radio spectrum, supporting everything from amateur radio communications to public safety networks. These frequencies offer reliable local coverage and occasional opportunities for impressive distance work when conditions are favorable....
Fred C (W6BSD)
If you've experimented with HF antennas, you've probably encountered the Half-Wave End-Fed (HWEF) antenna. It's popular for its simplicity, ease of deployment, and ability to resonate on multiple bands. In my previous post, I outlined several significant drawbacks of HWEF antennas, including their...
Fred C (W6BSD)
Half-wave end-fed (HWEF) antennas have gained popularity among amateur radio operators for their simplicity, versatility, and ease of installation. While they have a few notable benefits, they also have many problems that make them less than ideal. Here's why I'm not totally sold on HWEF antennas....
Fred C (W6BSD)
I discussed an educational club activity in my previews blog post. The goal was for the club's junior members to build a Delta Loop antenna. I gave them the minimum number of instructions, and they had to figure out all the antenna dimensions and the mechanical structure to support the loop....
Fred C (W6BSD)
Now and then, some folks from the San Mateo Radio Club get together at the park to work on a ham radio educational experiment. We cover operating HF, experiments with feed lines, building antennas, or any other ham radio project. These meetings aim to demystify and familiarize beginners and...
Fred C (W6BSD)
The Hustler 4BTV antenna is a vertical HF antenna known for its efficiency, durability, and versatility across multiple bands. However, if you want to use that antenna to tap into the 17-meter band, you'll need to modify it by adding a dedicated wire. This blog post describes how to include the...
Fred C (W6BSD)
A ground-plane antenna, also called a quarter-wave or a monopole antenna, is widely used in radio communication systems. It is relatively simple in design and consists of a vertical conductor, typically a metal rod or wire, mounted above a conducting surface known as the ground-plane. The...
Fred C (W6BSD)
A couple of weekends ago, I took my trapped vertical antenna apart to clean it up, ensure every component was in good working condition, and fine-tune it. While working on the antenna, I noticed that the Common Mode Current choke box had a crack due to the hot California summer sun making the ABS1...
Fred C (W6BSD)
The Hustler 4BTV For most of my HF traffic, I use a Hustler 4BTV antenna. The antenna is a vertical trap antenna capable of working the 40, 30, 20, 15, and 10-meter bands without using a tuner. I installed this antenna five years ago, and it has always worked fine, with a reasonable SWR on all the...
Fred C (W6BSD)
Leslie Moxon, G6XN, invented a two-element in the 1950es, named after him. Less Moxon published an article in a QST magazine issue from 1952 titled Two-Element Driven Arrays describing his antenna. Since then, the Moxon antenna has been referenced several times in the QST magazine.123 The Moxon...
Fred C (W6BSD)
A Double Bazooka Antenna is a broad-banded half-wave Antenna. This antenna can operate efficiently across an entire band without needing an antenna tuner. In the 1940es, the MIT staff designed and developed this antenna as a radar antenna for the military. Like a dipole, the Double Bazooka is a...
Fred C (W6BSD)
I gave a presentation on antenna modeling software to a couple of clubs in California and Oregon. From the physical antenna design to the matching network, we designed the antenna live with the participants. Here is a little more about the talk: During the first part of the talk, we go through...
Fred C (W6BSD)
Field Day 80/40-meter antenna The 2021 Field Day was the first time member of the San Mateo Radio Club met in person since the pandemic. It was nice to see friends again after so long, but the most enjoyable part was to be in a group of people working toward the same goal. Smith Chart dipole on...
Fred C (W6BSD)
The state of California and San Mateo County have eased COVID restrictions. It is why the San Mateo Amateur Radio Club has decided to have their Field Day operation at the usual location, Beresford Park. Dipole 40-meter branch The club's Field Day committee1 decided to build a new multi-band...
Fred C (W6BSD)
Our main goal as Amateur Radio Operators is to make sure that as much of the power coming out of the radio as possible is radiated by the antenna. The maximum power transfer occurs when the power source, the radio in our case, and the load or the antenna are a match. When the source and the load...
Fred C (W6BSD)
Is Resonance required? Important This is an extract from the ARRL Antenna book1 Please recognize that an antenna need not to be resonant to be an effective radiator. There is in fact nothing magic about having a resonant antenna, provided of course that you can devise some efficient means to feed...
Fred C (W6BSD)
Over the last few months, I have participated in an increasing number of discussions, either on local repeaters or in zoom meetings, about newly licensed hams interested in operating in the HF bands. Two main questions kept coming back: what radio to buy and what antenna to use. It is why I have...
Fred C (W6BSD)
When I build or install a new antenna, I always run a series of tests. Like everyone else, I look at the resonant frequency and SWR. But to see how the antenna is performing, I run WSPR1 for a few days. Then I use the data collected by WSPR Net to draw the graphs that can be seen in my previous...
Fred C (W6BSD)
I live in the middle of Silicon Valley in a suburban setting with small front and back yards. My property does not have tall trees to take advantage of when installing an antenna. Given these conditions, my best option was to use a vertical antenna. I got a Hustler 4BTV resonant on the bands from...