Electronics

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 with man-made interference. Noise Power Noise Power is the integral of the noise power spectral density over a given bandwidth, usually […]

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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 couple of weeks ago (it never materialized, but that’s beside the point) and I noticed that my noise floor had gone […]

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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 priced around $62 on Amazon. I thought this was a cracking deal. Upon testing the thing out, I found that the […]

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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 know why 50 ohms was arrived at as a sort of standard for radio applications, you can read this post. In […]

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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 a whole lot more upon them. I first tried QUCS about a ten years ago, and for whatever reason (lack of […]

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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. After all, if it’s such an easy fix, why not? I would like to report that I found no disconnected ribbon […]

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Antenna Tuners, Impedance Matching, and SWR

Antenna tuners seem to be some of the most misunderstood devices in all of amateur radio. In this article, I’ll try to explain what is happening when you use an antenna tuner. I’ll try not to get too much into mathematics, and I’ll also try to squash a few myths. I really don’t like the […]

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PL-259 Soldering

Do you solder the coaxial shield to the connector body when installing a PL-259 plug? What are those holes really for? I’ve been installing PL-259 plugs onto coaxial cable since I was about 16, and I’ve never soldered the body of the connector to the braid. I’ve not had any problems from not soldering the […]

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Alpha Delta Switch Arc-Plugs

I recently bought a couple of Alpha Delta coaxial switches, and noticed they come with a built-in surge arrester which can be replaced after a surge. They call them “Arc-Plugs”. These are on sale at DX Engineering for $9.99 each. I thought that was a little steep. When the switches arrived, I took at look […]

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IC-7300 Average SSB power modification

If you Google the title of this post, I’m sure you’ll come across some results which detail a very simple modification you can make to your IC-7300 which some believe increases the RF output power. This is vague and misleading. The PEP (Peak Envelope Power) of the IC-7300 is rated at 100 watts. This would […]

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