So I built a variable coupling loop. I'm not limited to 1/5, 1/4 or 1/3 size coupling loops like in the experiment I did before this way. During my experiment I tried several options and finally get best SWR all bands with a size between 1/3 and 1/4 size of the main loop. Especially on 60m and 40m the SWR is significant better. My advice to loop builders would be just to experiment till you get best results. You might end up with a 1/5 size or any other odd size coupling loop. I think all is depending on the size and material used for the main loop and the pickup loop, the capacitor, the coax and since there is a slight difference between homemade loops there is always a different result.Actually I was a little surprised with the outcome of this experiment. I use a coupling loop now which is between 1/3 and 1/4 size of the main loop. SWR on 60 till 15m now is below 1:1.6. I think that is a very good result. I consider my magnetic loop ready to go now. Now next thing.....testing on air.
For those that are interested. My magloop consists of 1 box with 500pF varco (which has been described earlier), 3 pieces of PVC tube, A length of 2,7m bamboo 9 75 Ohm coax, a length of 80cm 6mm wire for the coupling loop, 2m RG58 coax.
Hallo Bas, dat zijn interessante experimenten. Je zou denken dat daar wel formules voor zijn. Maar wat je zegt het hangt ook af van het gebruikte materiaal. 73 Paul PC4T
ReplyDeleteTheorie is vaak anders als in de praktijk. Er zijn bijvoorbeeld ook formules voor het bouwen van een HB9CV zoals ik die gebruik op 10m. Maar door exeprimenten ben ik op heel andere maten uit gekomen. 73, Bas
DeleteKE7TDY - I am working to amass resources needed; in time I'll DX your magloop with my DDRR (flat side) coat hanger - 73 my friend - N1PKE, pro tempora! POST: 10 OCT 17. 09:05Z-UTC.
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