Magnetic Loop for 40m, 30m & 20m

Contents Section 1 | Introduction Summary Main Parts Specifications Section 2 | Construction Aluminium Preparation Frame Construction Loop Wrap Coupling Loop Capacitor Motor Control Control Box Section 3 | SWR and BW 40m Band 20m Band Section 4 | On Air Experience Loop Tuning Example First Contact Contact with Portable Station

Section 4 On Air Experience

Here in Australia I have what is known as an "F" call license. This is an "entry level" Foundation License. It has restrictions which only allows me to transmit with a maximum power level of 10 watts and restricts transmissions to the 80m, 40m, 15m and 10m HF bands. 2m VHF and 70cm UHF are also allowed.
Transmitting only 10 watts into my newly created magnetic loop standing one loop diameter above the ground on 40m, I wasn't expecting too much. Even after reading a lot material on magnetic loop antennas and being careful during construction trying not to cut corners.
The first contact I made was with an operator in Griffith about 500km(~300mi) away. Since then I have been responding to stations calling CQ with a pile up of people in an attempt to compare myself to others. I have easily broken into the pile ups with signal reports somewhere in the middle of others located near me. The noise floor is great on 40m, around S3. Quite pleased with the results.

Loop Tuning Example

A quick video showing the magnetic loop roughly tuned into a station for receive. Tuning is done manually using push button control with the aid of the audio and signal strength meter.

First Contact 500km(~300mi)

Contact with Paul who works portable 650km(~400mi)

Link to Paul's Website showing some photo's of his portable set up.

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