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Hi Victor Copper pipe, it stays rigid, though coax works. Re the main loop, that also should be copper pipe. Reason, losses, and if use coax and it moves/flexes then its out of tune and you will

One more question: is it better to make the coupling loop with coax (ie RG213) or copper pipe? Thanks.

or more precisely: /g/loopantennas/files/NX0E_hybrid_coupler/loss_precise.jpg

The unshielded coupling loop is likely to produce the lowest losses. When using a toroid, especially on the lower frequency bands, a high permeability core material is required. These tend to be

Hi, I'm very pleased for the bunch of answers and advices you tell me. Thank you very much. At first I'll made an unshielded coupling loop so it's the easiest method althougt the toroid is an

Hi Hisami, I've attached a new file: /g/loopantennas/files/NX0E_hybrid_coupler/loss_plot.jpg. V(n005) is the voltage at the source. The losses are not 9 dB but about 3 dB. Kind

Hi All, A friend told me. this this type of Hybrid is often used in 4 square vertical systems. for example as

Hi Piotr, Thanks for the information and LTspice file. The 9dB loss is a bit large, but the clean phase is wonderful. tnx & 73, Hisami

Yes, this would work quite well. In technical terms, its called a Rogowski Coil. Uncle and amateurs have fed the base of a water fountain using a Rogowski coil as well as feeding trees. I'[ve never

Hi, Victor. Not to derail the discussion too much, but the toroid coupling method shown in figure 32 of that link works very well indeed. Not only is it mechanically very simple and robust, but you

Hi Dave Snake oil..lol Just dont make any improvement..good selling point though! Simon g0zen, ex maker of 160/80m mag loops that can get into USA, Caribbean etc from UK ssb.. ( now live on

If you look at the physics of the "shielded" loop, you will rapidly realize it is NOT SHIELDED from the induced currents! That's the whole reason for the gap at the top high-Z point, opposite the

I would agree with Simon. Use an unshielded coupling loop and place an effective common mode choke on the feedline, and also on any control cables. Regards, Martin

OK. . . 90 degree hybrids with mulitoctave frequency are possible but this is the 21st century. . . Buy a dual channel SDR receiver with matching "IF signal handling" chains and create the 90 degree

An addition: As you can see from the phase plot the deviation from 90 deg is less than 5 deg for the range: 2.4 - 37 MHz. The design can be easily scaled to another frequency range. But note: there

A few years ago, a similar topic appeared in another group: /g/SimSmith/topic/69302617. Last year, Chris Smith NX0E shared his hybrid coupler design with me. He based his design on

Hi Unshielded..been there done it..dont waste time on shielded. Its not the antenna, its just the coupling to the antenna which has already received any noise. A common mode choke in coax by antenna

Hi all and thanks for accept me in the group. I'm building a magnetic loop antenna for TX and I slightly follow the instructions in

I think it is feasible to chose component values that would produce a 90 degree phase shift at a given frequency, especially if this is somewhere close to resonance, and if you are only interested in

Hi Martin and All Illustration of SCPQ-10.5 Datsheet. I thought about the "or some other element" that Martin mentioned. Most simple one is capacitance between the coil. I did a simple simulation in