tag:blogger.com,1999:blog-953397841255562532.post1489403680613191088..comments2023-09-30T14:59:05.385+01:00Comments on G4ILO's Blog: The Wonder LoopAnonymoushttp://www.blogger.com/profile/11984840704237681015noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-953397841255562532.post-29659524885137473992009-07-31T13:37:37.265+01:002009-07-31T13:37:37.265+01:00Thanks for the suggestions Myles. I did consider u...Thanks for the suggestions Myles. I did consider using soft copper pipe but the aim was to make a loop that could be quickly set up then taken down again after use and I was not sure how that material would stand up to being coiled up and uncoiled many times.<br /><br />I have also seen some interesting ideas for homebrewing capacitors. Seems like too much work for QRP as a fairly ordinary capacitor seems to work fine, but if I wanted to make a loop for higher power then it might be worth trying.Anonymoushttps://www.blogger.com/profile/11984840704237681015noreply@blogger.comtag:blogger.com,1999:blog-953397841255562532.post-38800596592245653672009-07-31T13:22:15.518+01:002009-07-31T13:22:15.518+01:00the spirals of copper pipe are used for airconditi...the spirals of copper pipe are used for airconditioning installations, it is very soft. and easy to solder at the ends for connection to capacitors.Myleshttps://www.blogger.com/profile/01853706355827925272noreply@blogger.comtag:blogger.com,1999:blog-953397841255562532.post-49252206311282941392009-07-31T13:20:39.983+01:002009-07-31T13:20:39.983+01:00soft annealled copper pipe is sold in coils, 1/2&q...soft annealled copper pipe is sold in coils, 1/2" and 3/4". It is very easy (by hand) to bend into a loop, simple size would be 1 metre in dia.<br />Capacitors to tune the loop can be 200pF variable with 1mm air gap between stator and rotor, good for 5 watts, 80M up to 12M.<br />I also experiment with materials.<br />I started with caps made from aluminium foil freezer bags and crdboard, for Rx, too easy, 200mm square to tune 7MHZ on a 1 metre loop made from RG213.<br /> <br />Next cap was made using PET the stuff coke plastic bottles are made from.<br /> <br />A 2 litre bottle provided ample supplies, then inserted a coke can into another insulated by the PET, 100 watts no heating, but not conclusive<br />and not easy to slide in and out.<br /> <br />Next is glass as a dielectric, good for 50KV, I bought many small picture frames 90c each , 150mm x 100mm with 1.5 - 2.00mm thick glass.<br /> <br />Some brass sheet from a remote controlled hobby shop, it's very thin I cut it with scissors, and made a sandwich.<br /> <br />2 outer with one inner separated by 2 sheets of glass, magic capacitor good for 100 watts for 5 minutes, still developing a variable cap, which will<br /> <br />have one piece (inner) for highest freq. and one beside it to fine tune, I just slide them in and out of the main sandwich.<br /> <br />I will supply pics if required.<br /> <br />I you have a ganged variable aluminium cap, to increase the working voltage just use 2 x gangs (stators) and not the rotor.Myleshttps://www.blogger.com/profile/01853706355827925272noreply@blogger.com