If there’s one instrument that hams and other radio enthusiasts covet, it’s the venerable Bird 43 Thruline wattmeter. The useful RF tool has barely changed in the nearly 70 years since it was first ...

The idea behind watts seems deceptively simple. By definition, a watt is the amount of work done when one ampere of current flows between a potential of one volt. If you think about it, a watt is ...

You need an audio wattmeter to measure the power output of your audio amplifier? You need one LM3915 IC and add a few passive components and you got a simple but effective audio wattmeter. This sound ...

Although the basic wattmeter covers 1.501 kW, some people might be interested in other ranges. So, we will show here a multirange version, with full calibration (see the detailed schematic). The basic ...

Last month, I designed a good 1-mΩ> shunt ("What's All This Shunt Stuff, Anyhow?" April 29, p. 94). Now we'll use it in a 1.5-kW wattmeter. This one is optimized for the 80- to 130-V ac range, and for ...

(a) A current of 20 A flows through a load having a resistance of 2 Ω. Determine the power dissipated in the load. (b) A wattmeter, whose current coil has a resistance of 0.01 Ω is connected as shown ...