Foundations Of Amateur Radio

Foundations of Amateur Radio A question that occurs more often than you might think is one related to powering your radio. It comes in a few different flavours, like: "I want to install a radio in my car, how do I power it?", or "I want to operate portable, what's the best way to power my radio?" or "What power-supply should I buy?" There are many more versions of this, but they all come down to the same underlying challenge. I spoke about sizing a battery a couple of years ago, but that's not the only consideration. If you look at the power specifications of my Yaesu FT-857d, you'll see 13.8V DC +/- 15%, Negative ground, 1 Amp on Receive and 22 Amp on Transmit. Based on this I purchased two 26 Amp Hour batteries and a 45 Amp variable power supply. My amateur license restricts me to 10 Watt and I tend to operate using 5 Watt. On receive the actual draw, specified in the documentation at 1 Amp doesn't go above 0.5 Amp in typical use. Transmit, specified at 22 Amp doesn't go above 3.6 Amp at 5 Watts and at