Magnetic Loop Build 15 thru 75 Meters High Power/High Efficiency

Please do not contact me regarding build plans and specs. It's just too much to cope with and way too elaborate. Stick to the online calculators for dimensions as well as the abundant resources available. One word of caution- multi turn loops are difficult to get working well. Start with a single turn loop and go from there. The spacing between the large driven loops is critical as the closer the spacing, the more inductance you will gain at the expense of stability in the magnetic field. Yes, it will take less pF to tune but will become unstable under modulation and high power. You must find a balance between stability, tunability and efficiency when running multi turn loops. That said, The loops I have thrown together work really well despite the builder ;-) I am no expert but enjoy playing with these. If I lived in a HOA or other antenna restricted qth I would have no qualms about running one of these.
A word of caution: These antennas can be incredibly dangerous to living things in close proximity to them. Dogs, cats, anything while transmitting on high power. It's not just the voltage at the capacitor which can be 10's of thousand of volts but also the field of radiation! Be careful and make darn sure there is nothing around the antenna and that it is NOT accessible while in TX.

I focused on high power and the best efficiency I could muster before it turns into a dummy load(folded dipole). It is a remarkably effective antenna as the videos to come will show. This build should handle about a 250-300w+ drive at least on 15 thru 40 meters. This is part 1 in a series.

Update: I added a 3rd loop and now loads on 75 meters with app' 10-20 pF of capacitance. However, with the spacing used here it is too close. Under modulation with 100+ watts the magnetic field is unstable and swr jumps all over the place. Stable with a carrier but I suspect spacing is too close.

Side Note: You will notice the more efficient you make your loop the greater the bandwidth you will have. Every calculator supports this as well as real world testing. Something to consider as I am constructing a loop for 30 meters.

Music: http://www.bensound.com/royalty-free-...