One of my hobbies is amateur radio.
During the Covid-19 pandemic I took the opportunity to get my amateur radio license. I started with the Technician class license and about nine or so months later, I earned my General class ticket. I’ll probably work on getting my Extra Class ticket before too long.
Amateur radio is a good hobby for someone like me. There really is no shortage of things you can investigate. One of the things I’d like to do is finish a 20 meter magnetic loop antenna that I started researching. One of the characteristics of this kind of antenna is that you need a high quality air or vacuum variable capacitor for tuning the loop. I bought a new vacuum variable capacitor for a few hundred dollars. They are amazing beasts. The RF voltage and current at the top of a magnetic loop antenna are intense!
Here’s an image of the current conditions:
I’m not up to speed on all of the metrics reported on these charts. As usual, you can find a good web page that goes into more detail.
The numbers I currently look at include the SFI (Solar Flux Index), the SN (Number of Sunspots), the A and K values, and the HF Conditions.
In the above, the 30 meter and 20 meter bands are open (“Good.”) Other bands are fair or poor. I usually work on 20 meters when I have time to “go play radio.”
An SFI of 100 or greater and a sunspot count of 80 or more usually seems to bode pretty well for HF propagation. Low A and K values are important too.
All that being said, you don’t really know how the bands are going to perform until you get on the air. And due to fluctuations in band conditions, the bands can open and close quickly.
It’s all part of the hobby. If you love it, you love it.
John Sambrook 