Construction Project – QRP 1:1 Choke

I have constructed a QRP 1:1 current choke for a new homebrew 28.4 metre ZS6BKW antenna fed with 11.1 metres of 300 ohm window ladder line. The choke is placed at the end of the 300 ohm cable as a means of reducing common mode current. This choke will be used in combination with an…

Construction Project – Lightweight Telescopic Pole Support

This post was inspired by a discussion at the UK SOTA Reflector on a small commercial telescopic pole support (fishing pole support), ideal for lightweight VHF or HF antenna poles. https://reflector.sota.org.uk/t/small-mast-holder-from-decathlon/33238 Project construction time 10 minutes, cost $3.75. My portable lightweight 6m fibreglass telescopic pole is used to support a range of different VHF-UHF antennas;…

Antenna Project – Recycle an old aluminium VHF TV antenna and build a hand-held 2m yagi for 144.2 MHz

This 2m yagi antenna is light on the back-pocket and relatively easy to construct. This project starts with an old VHF TV antenna purchased from a local ‘Green’ recycle depot for $5.00 AUD. The repurposed TV antenna was a Phased Array comprised of two aluminium booms and four elements or eight 1/4 wave elements. Each…

RF Trap Resonant Frequency

I am constructing a lightweight 40/30/20/17/15m trap style inverted V dipole antenna for SOTA purposes. Can you use an antenna analyser to check the resonant frequency of a HF trap? Yes you can, here is a practical solution. The purpose of this post is to demonstrate how you can use a modern antenna analyser to…

Antenna Project – 2m 145 MHz Rectangular Loop

Peter VK3YE recently published a 2m rectangular loop antenna article in Amateur Radio Magazine edition 5 (Sep-Oct 19). The feedpoint impedance of the 2m rectangular loop is 50 ohms thus avoiding the need for a 1/4 wave impedance transformer. Are interested in a 6m oblong loop? I have constructed the lightweight 150 gram (5.2 ounces)…