The LZ1AQ Loop Amplifier looks like a stable solution for my wideband magnetic loop project. Time to test a prototype on a breadboard. Read more
Category: Shortwave Radio
Head End Instability – LTSpice Limitations
LTSpice limitations can bite. The macro models used in simulation don’t sufficiently take into account parasitic and circuit layout effects that can haunt you down the road. Read more
Wideband Loop Base Amplifier Feeds Receiver
We complete the electronics requirements for our loop antenna design with a wideband loop base amplifier to match the transmission line to a receiver. Read more
Wideband Loop Transmission Line Choices
With a little ingenuity, you can select either coaxial or network cable for your wideband loop transmission line. Either will work, but I am going with twisted pair. Read more
Wideband Loop Transimpedance Op Amp Selection
You can select candidates for a wideband loop transimpedance op amp by reading data sheets and simulating performance in LTSpice. Read more
Wideband Loop Antenna Implementation Begins
Enough theory. It’s time to start the wideband loop antenna implementation using real parts and circuits. Read more
Loop Current-to-Voltage Converter – A Short Story
A transimpedance amplifier provides a near perfect loop current-to-voltage converter. It provides lots of gain while keeping your loop in wideband or short-circuit mode, which is what you need. Read more
Compare Wideband Loop Amplifier Performance
With LTSpice and a loop antenna model, you can easily compare wideband loop amplifier performance. Here is my evaluation of several popular circuits. Read more
How Wideband Loops Work – Keeping Current
Wideband loops work by extracting signal current independent of frequency. You will find the theory completely different from traditional tuned loops. Read more
Magnetic Loop Voltage – Inducing a Signal
Whether we are using an actual magnetic loop antenna or simulating an equivalent circuit, we need to understand how a signal voltage develops across the loop. Where does it come from? Read more