Funny you have just published this as today I've just finished my 6m mag loop too... An offcut of elliptical waveguide rather than plumbing pipes. A coupling loop rather than the ferrite and a small butterfly rather than your co-ax inner. Just over a foot in diameter but just like you I'm very impressed with it's performance. Picking up Slovenia from inside the kitchen here in Scotland. Q is very high (showing good low losses) & certainly need to retune the capacitor depending on where in the band working. Totally agree with you that these little mag loops can be great fun to build & play around with & that they can provide amazing results in restricted circumstances.
Nice work! Sounds like a piece of kit! Looking forward to further experiments with magnetic loops in the future. If have some pictures of your build (either "in progress" of finished product) feel free to share!
@@noelmoore4474 lb5jj was also interested in seeing the photos so rather than bandying email addresses around here (that can lead to excessive spam) I've sent the photos through to him directly so if you contact him he could probably send them through to you too. Regarding my design source there wasn't one (except for the generic design suggestions for mag loops:- a) circumference... generally try to be just less than a quarter wave on the highest freq of operation, hence less than 1.5m for a 50MHz (6m) antenna... ie less than 40cm(ish) diameter.... the actual loop length used here was actually confirmed the other way around... that is the length of the off-cut now what could I use that for... hey that should do 6m b) capacitor - expecting something in the 5-50pF region would be general ball-park... that butterfly in the junk box looks about right & has a nice spacing I'll give that a go.... power level with that spacing.. no idea... certainly high enough for ft817... I've not tried on higher power yet but expecting 10-20W capability (wind the tx up until it flashes then don't quite do that again! (one short flash generally doesn't damage an air variable cap noticeably). c) coupling loop dimension ... start with 1/5th dia of main loop then try making it smaller/larger until you get the best match. The main thing is keeping the losses low (dual gang airspace or butterfly cap generally OK for QRP) Calculating to 9 decimal places & vacuum variables nice but certainly not essential.
Let say this is a genius design, especially, I like this design of the capacitor! Thanks for sharing your idea and video. "73"!
I liked how you made the tuning capacitor, inside the loop, and the coated copper pipe made for a very tidy build. Nice job. Thanks for the video.
Thanks :-)
Looks nice!
Thanks!
Is it a ham antenna or cb one
6m ham band
Funny you have just published this as today I've just finished my 6m mag loop too... An offcut of elliptical waveguide rather than plumbing pipes. A coupling loop rather than the ferrite and a small butterfly rather than your co-ax inner. Just over a foot in diameter but just like you I'm very impressed with it's performance. Picking up Slovenia from inside the kitchen here in Scotland.
Q is very high (showing good low losses) & certainly need to retune the capacitor depending on where in the band working.
Totally agree with you that these little mag loops can be great fun to build & play around with & that they can provide amazing results in restricted circumstances.
Nice work! Sounds like a piece of kit! Looking forward to further experiments with magnetic loops in the future. If have some pictures of your build (either "in progress" of finished product) feel free to share!
Would also be interested in seeing the source of your design.
@@noelmoore4474 lb5jj was also interested in seeing the photos so rather than bandying email addresses around here (that can lead to excessive spam) I've sent the photos through to him directly so if you contact him he could probably send them through to you too.
Regarding my design source there wasn't one (except for the generic design suggestions for mag loops:-
a) circumference... generally try to be just less than a quarter wave on the highest freq of operation, hence less than 1.5m for a 50MHz (6m) antenna... ie less than 40cm(ish) diameter.... the actual loop length used here was actually confirmed the other way around... that is the length of the off-cut now what could I use that for... hey that should do 6m
b) capacitor - expecting something in the 5-50pF region would be general ball-park... that butterfly in the junk box looks about right & has a nice spacing I'll give that a go.... power level with that spacing.. no idea... certainly high enough for ft817... I've not tried on higher power yet but expecting 10-20W capability (wind the tx up until it flashes then don't quite do that again! (one short flash generally doesn't damage an air variable cap noticeably).
c) coupling loop dimension ... start with 1/5th dia of main loop then try making it smaller/larger until you get the best match.
The main thing is keeping the losses low (dual gang airspace or butterfly cap generally OK for QRP)
Calculating to 9 decimal places & vacuum variables nice but certainly not essential.
@@StreakyP Thanks.
Just subscribed
Welcome!
I have to try this.
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Good luck, and let me know how it turns out!