Understanding dB, aka go easy on your HF amplifier!
I was listening to a couple of guys on the 20m band today and they were discussing amplifiers… “Yeah, this amplifier will do 1500W. The last one I had would only do 1000W so...
Category: Electronics
UR6QW
Sergey, UR6QW is a ham radio operator in Ukraine who designs and builds excellent audio devices for ham radio operators. I have been a fan of Sergey’s work for years and have written several...
Icom IC-7300 & IC-7610 “Built-In” Tuning Pulser
Overview A tuning pulser is a device which generates a series of short-duty cycle tone bursts which are applied to the audio input of a transmitter. Instead of tuning up a tube linear amplifier...
Antenna Materials & Efficiency
You can not make a very good antenna using insulators like PVC tubing, drinking straws, or nylon rope. I think we can all agree on that. Why? Materials like plastic are electrical insulators, and...
Noise & Receiver Performance
In this article, I’m going to cover Noise Figure, Noise Factor, Noise Power, Receiver Bandwidth, and how they can affect overall radio receiver performance. Contrary to popular belief, these metrics have nothing to do...
Charger Radiated Emissions
I usually have a respectable HF noise floor at home, for which I count myself lucky in today’s sea of cheaply made switching power supplies. However, we were expecting some severe winter weather a...
Baofeng Cemetary
As of the date of this post, you can get a Baofeng UV-5R for $28, or buy two for $50. Dirt cheap. I bought my first Baofeng UV-5R back in 2012 when they were...
What is characteristic impedance?
The RF world is full of esoteric terminology, and not least of these is characteristic impedance, or Z0. Most coaxial cables have a characteristic impedance of 50 or 75 ohms. If you want to...
QUCS for Filter Design
Introduction QUCS, or Quite Universal Circuit Simulator, is a freeware utility that allows you to draw circuit schematics, and perform AC & DC simulation, noise simulation (for S-parameters, and AC simulations), S-parameter simulation, and...
Radioddity GD-77: A look inside
After many people telling me that my blank screen issue is down to a loose ribbon cable, and since Radioddity are replacing my defective GD-77, I saw no harm in having a look inside....