The QRPer Board

I just built a magloop antenna with a 10 foot RG-213 radiating loop and a 2 foot 12 gauge coupling loop. The tuning capacitor is spec'ed for 4 - 90 pf (it's actually a dual section 8 - 180 pf capacitor, but I wired it in series to handle 5w). According to 66pacific.com and my testing, it can be tuned to work 10m - 12m.
There are a lot of commercial antennas that boast 40m - 10m operation with a similar setup. I assume that they all have a beefier capacitor, but how effective are those antenna on the highest and lowest bands? Would a different capacitor increase the functionality of my magloop? (I am happy with it as is, so any changes would be for the next antenna).

73,
Mike, KL7MJ

Hi Mike, willing to go down in frequency I think that you should increase your loop size



and then use a vacuum capacitor to tune it





seriously, have a look here (use a translator)

http://www.radioamatoripeligni.it/i6ibe/loop/loop.htm

Those loops are awesome, but probably more than my wife will allow in our yard!

I'm really just curious how the commercial loops are able to cover more bands than the magloop calculators say is possible - do they come with different radiator loops for the high/low bands, or do they just overcome the size issue with more capable capacitors?

73,
Mike, KL7MJ

The capacitor AND the loop size

http://www.radioamatoripeligni.it/i6ibe ... 20loop.jpg

ideally to cover 80 to 10 meters you'd need a (vacuum) capacitor with a 5pF to 1KpF range, but such a critter doesn't exist, so the solutions are two, one is changing the loop size to be able to reduce the needed capacity, and two add switchable fixed capacitors (series/parallel) to be able to obtain the value needed for a given band/frequency, in all cases consider that the capacitors must be able to stand quite a lot of Volts, even if operating QRP

Since you're out hunting loop, you may also consider having a look at the so called "Army Loop"

https://www.qsl.net/zl1bpu/DOCS/The%20A ... trated.pdf

https://owenduffy.net/blog/?p=3026

http://webclass.org/k5ijb/antennas/Smal ... TERSON.htm