I am always experimenting with different types of antennas. Recently, I decided to compare a DIY Passive Loop to a Terminated Folded Dipole antenna to see how they performed against each other.
To make the DIY Passive Loop, I followed a design from swling.com that uses coax and a self-made balun. The Terminated Folded Dipole, on the other hand, is a commercially available antenna that I installed in my attic. Both antennas were connected one at a time to an SDR dongle and tested on various frequencies.
6MHz
When I tested the Terminated Folded Dipole on 6 MHz, I noticed that it had a high noise floor and interference issues. The signal quality was not as good as I had hoped. However, when I switched to the DIY Passive Loop at the same frequency, the noise floor was noticeably lower, and the signal quality was much better.
5.910 MHz
I then tested the antennas on 5.910 MHz, and the results were quite different. When I used the Passive Loop, I could not receive a station that I was able to pick up with the Terminated Folded Dipole. I also noticed that the DIY Passive Loop had no significant improvement when I rotated it.
21 MHz
Next, I tested the antennas on 21 MHz, and the results were again different. While the Terminated Folded Dipole had some interference issues, it performed better than the Passive Loop. When I rotated the loop antenna, I did not notice any significant improvement in signal strength.
Final Thoughts
Overall, I found that the performance of these two antennas varied greatly depending on the frequency. While the DIY Passive Loop performed well at some frequencies, it was not as good as the Terminated Folded Dipole at others. In terms of ease of use, I found the Terminated Folded Dipole to be more convenient as it was a commercially available antenna that required no DIY skills to install.
Both antennas have their pros and cons. If you are looking for a cheap and easy-to-make passive antenna, then the DIY Passive Loop may be the way to go. However, if you want a more reliable and convenient antenna with better performance, the Terminated Folded Dipole is a better choice.