In September 2023, I wrote a review about the 7-band Cobweb antenna manufactured by AWK in Poland. This symmetrical, or balanced, antenna is fed with asymmetrical, or unbalanced, coaxial cable. To prevent the coaxial cable from becoming an active part of the antenna, it is necessary to place a 1:1 The post Replacing the 1:1 balun for a better performing Cobweb antenna appeared first on PA9X ..read more

Upon request, I build 1:1 baluns (aka common mode chokes) for other amateur radio operators. I often receive questions about the maximum power at which the balun can be used. In response, I provide the maximum load for use in SSB mode. I do this for a reason, as there The post What are PEP power and Duty Cycle in amateur radio? appeared first on PA9X ..read more

It seems like some kind of magic object, the 1:1 balun. Some say it can solve many antenna problems. It could turn a bad SWR into a good SWR. Increase antenne bandwith. Reduce interference in reception. Prevent RFI that causes interference to electrical devices at your neighbors and your own The post Why does an antenna need a 1:1 balun? appeared first on PA9X ..read more

The space available for an HF antenna at my location is very limited. The plot where I live is only 5 meters wide. If you want an HF antenna that covers the 20, 17, 15, 12, and 10-meter bands, you quickly end up with an antenna like a Cobweb. I The post Review of the 7-band AWK Cobweb antenna appeared first on PA9X ..read more

For more than eight years I have been battling manmade noise, or QRM. In this, I am not alone. The entire ham radio world is experiencing a rapid increase in manmade noise. The result of the many electrical devices used in the home. From phone chargers to LED lights and The post Using AI to strip a radio signal from QRM appeared first on PA9X ..read more

It seems like some kind of magic object, the 1:1 balun. The object could solve many antenna problems. It could turn a bad SWR into a good SWR. Reduce interference in reception. Prevent RFI (RF strikes in equipment) and cause interference to neighbors and in one’s own shack. To even The post Why does an antenna need a 1:1 balun? appeared first on PA9X ..read more

You often hear about it and it is a hot topic on forums, repeaters and club gatherings. I have interference (RFI) on my equipment or that of my neighbors caused by my own radio signal. What can I do about it? First of all, the best strategy is to tackle The post How to prevent RFI caused by EndFed, vertical and dipole antennas  appeared first on PA9X ..read more

Because of the very limited space for antenna placement, 20m2 at most, I have experimented a lot with different antennas for transmitting and receiving over the past few years. Most important for me is the performance on the 10 meter to 20 meter band. For those bands, I have now The post The Cobweb vs Rybakov vertical antenna part 1 appeared first on PA9X ..read more

It has been around for a long time, but is only used on a small scale in the ham radio world; diversity reception. This is a pity, because diversity reception not only offers the possibility to reduce QSB (fading). With diversity you can also eliminate QRM (manmade noise) very effectively. The post Get rid of QRM with diversity mode appeared first on PA9X ..read more

In the world of amateur radio, the terms balun, unun, common mode choke, line isolator and impedance transformer are often used. But also often mixed up and sometimes lead to heated discussions on forums and social media groups. For your convenience (you don’t have to ask on a forum or The post The difference between a balun, unun, common mode choke, line isolator and impedance transformer appeared first on PA9X ..read more