PD7MAA HOMEPAGE: Magnetic windowloop for 20m. no tuning ! Updated november 2011

A stealth solution for apartments ?
I made a wireloop on the inside of the wooden windowframe in my shack with a circumference of 6,20 meters. The tuning capacitor is made of 20 cm PVC coated copperwire. Feeding is done by a medium size Ferroxcube 4C65 toroid with 1 full turn at the antenna and 2 turns at the coax. For 100 Wats power use only a full size 4C65 or a FT140-61 and replace the tuning section by a pice of RG-213 that forms a high voltage capacitor. For 40 m use a pice of aprox 75 cm RG-213. You can even use a double switch to change bands.By means of 4 hand suckers this antenna can be placed on any medium size window.

First contact was made with Bari Itali with 5-7 report.This was followed that day by several qso's with HA, YT , and LZ . All made with 3.5 Watts SSB even S56EQC with a 5-9 report

. The antenna needs no tuning for the SWR is lower than 1:1.5 all over the band. This is not a wonder antenna but it gets you on the air for certain. Using 15 mm copper tubing drasticly improves efficiency.
When build as mini deltaloop whith the help of two 2m. fibreglass poles it becomes a nice small field antenna .
Give it a try !

You can find toroids and hamstuff at Haje Electronics

SEVERAL TOROIDS WERE TESTED , THE 4C65 PERFORMS FB

LOOP DATA ALTHOUGH THE BANDWIDTH ( Q-FACTOR ) DOES NOT MATCH

15MM COPPER TUBING LOOP

Magnetic loopantenna calculator by KI6GD : http://www.standpipe.com/w2bri/software/loopcalc.exe
The prog. doesn't have an icon, just klick in the white square above it's name .

DO YOU LIKE TO EXPERIMENT WITH ANTENNAS ?
Here's all you ever wanted to know about VSWR :

http://www.amateurradio.org.za/VSWR%20John%20Fielding%20Final.pdf

SOME OF MY OTHER PROJECTS.