I poked around on the Internet looking for a schematic for the HM-219 hand mic. Believe me, Icom didn't make it easy to find, but eventually I came up with a few helpful results I was able to piece together. Now, I know that if I'm going to build my own headset, I will need […]
This amateur radio hobby can be quite expensive. I've tried to be patient and frugal, and it has paid off. I'm fortunate to have acquired some quality used gear at affordable prices. Two of the transceivers on my desk currently are the Icom IC-7300 and IC-9700. These radios look and behave very similarly, and together […]
There are multiple ways to set up and use DSTAR on the IC-9700, each with pros and cons. The Terminal Mode using the External Gateway function is great for two reasons: It is easy to configure. There are only a few things to configure on the IC-9700, and a few settings on the hotspot. I'm […]
If you find yourself in the market for a new pickup truck, and you have more than a passing interest in off-grid power, then you HAVE TO check out what the wizards over at Ford Motor company have been cooking up in the 2021 F-150. Like many other auto makers, the gasoline powered models have […]
In a survival situation, you have to prioritize your effort and get the most urgent and important things going. At the top of the list is first aid. We aren't talking about minor quality of life treatments here. This is basic life support kinds of first aid - breathing and bleeding - the things that […]
I needed a new battery charger for my deep cycle AGM battery pack I showed in a previous post. I thought about building one out of parts from some old computer power supplies, but I ran into a good deal on this smart charger from Schumacher. The model number is SC1358. It's designed for all […]
Remember when you were a kid and every map you saw showed that Greenland and Antarctica were massive bodies of land? Then you grew up and at some point you realized that the world is a little different than you thought. That is, of course, because we mainly use Mercator maps. These maps represent the […]
Recently, I have posted back to back about maximizing power at the antenna, and about characteristic impedance. These conversations have touched on reflected waves and associated loss. I thought it might be good to drill down on this just a bit more, as these have been topics on my mind as I have been making […]
There are many different types of 50 ohm coax. Some thick, some thin, some rigid, some flexible. They also vary in factors of attenuation and RF leakiness, yet they are all said to be 50 ohm coax. But what does it mean when we say a coax cable is 50 ohms? If I pull out […]
QUESTION: How can we maximize power from the transceiver out through the antenna? ANSWER: Somehow, match the impedances at the transceiver and the antenna. That sounds simple enough, but let's dive deeper. The Maximum Power-Transfer Theorem states that to transfer the maximum amount of power from a source to a load, the load impedance must […]