Last month I wrote some about making a notch filter for the AM band. However, before you have any signals to notch out, you must first, of course, have some signal to begin with. Let’s talk a little ...

At present, portable receivers generally use ferrite rod antennas for LF and MF (below 2 MHz), and whip antennas for HF (up to 30 MHz). Each type has proved effective in its particular application.

[Avionics Today 09-17-2015] Cobham Aerospace Communications has developed a Wide Band High Frequency (HF) antenna capable of transmitting data at a rate 10 times higher than traditional HF antennas, ...

There’s a joke in the world of radio that all you need for a HF antenna is a piece of wet string, but the truth is that rudimentary antennas rarely perform well. Random pieces of wire may pull in some ...

The only way to determine the characteristics of an antenna is to measure its performance since theory alone cannot predict the actual results. The fields generated by antennas are extremely complex ...

In this application note we will explore antenna theory and design using EZNEC, an easy-to-use antenna simulator. We will measure the antenna’s characteristic impedance through our application board.

[K5ACL], aka [SignalSearch], recently brought his active receive loop antenna in off the roof to give it a checkup and perform any necessary maintenance. While it was in the shack, he took the ...