Johnson's Techworld

These days it is a tough job hunting for resistors in local shops. When we go there and wait for our turn, finally one or two of the

“Difficult Part of Easy BITX”: Trifilar and Bifilar Transformers, was easy after seeing a video by VU2TDD! Winding instructions from the Easy BITX manual were followed, for winding

Now the TOKO coils for 40m and 20m have been fixed. Next step is winding the toroidal transformers. Both trifilar and bifilar windings are needed for these. Few

In amateur radio, Intermodulation Distortion (IMD) is a form of signal interference that occurs when two or more signals interact within a non-linear device—such as an overdriven power

TOKO Band Pass Filter Coils seemed a bit tough as I am beginning the hand winding of the coils in Easy BITX after completing the assembly of other

This picture explains the various parts of the VU2EVQ design HF linear amplifier circuit. The Pi network of thick resistors form the attenuator for reducing the signal strength

VU2EVQ design HF linear amplifier has a nominal power rating of 100 W, and is meant mainly for 40m, though it can give same output on lower bands

Soldering complex PCBs—especially those involving high-density RF circuits or surface-mount components—requires a shift from “joining wires” to “precision engineering.” When dealing with multi-layer boards or tight footprints, thermal

Setting up a homebrew shack is one of the most rewarding milestones in amateur radio. It’s where theoretical physics meets the smell of solder. Your shack needs to

Had some difficulty in finding the last 100 nF capacitor to be soldered because the slot was a large rectangular slot for C59, unlike the small oval slots