SWLing Post Message Board

Secondly, at 1.8 MHz, maybe you need to significantly increase the both (1) the load inductance of the outer loop and (2) the intrinsic inductance of the inner loop. The CTL article says that for (2) you should use additional wire turns on the inner loop to increase the inductance, but that is a ve...

Thanks for the warm welcome. :) Well, I've been "following" you for some time and it's a pleasure to see you here ! Excellent to hear! Did you ever actually get around to building one? I have only simulated, but not yet actually built, the CTL. No, I just played with some NEC models but t...

spent a (short) bit of time playing with C1, C2 and RL but probably I'm missing something, I mean, I followed the directions in the comments, that is 1. Adjust C2 (outer loop capacitance) to be very large (e.g. 1000 pF), so that the outer loop is far away from resonance. 2. Use 4nec2 optimizer to ad...

First of all, welcome to the forum !! As for the CTL, I've played with it while designing the SULA and it's for sure an interesting design, I've just tried your NEC model and slightly changed it inserting the parameters for the ground CM Model of Coplanar Twin Loop antenna. CM Created by qrp-gaijin@...

I will check those out. let me know... as a note, a good combo for your QTH could be a LoG for the lower frequencies (lower SW, MW and below) and a SULA for SW and up to VHF, such a setup would give you an extensive bands coverage with just two antennas :) ! Also, your preamp/preselector may work p...

Hi I like experiment building my own radios: crystal sets, regeneratives with transistors and tubes, etc. Some months ago made a crystal radio with double tunning circuit: https://sbj.edu.mx/crystal-receiver/emilio-crystal-receiver.jpg This night i forgot turn off the audio amplifier (the box with ...

As for the LoG (Loop on Ground), check these http://radio-timetraveller.blogspot.com/2022/05/the-loop-on-ground-antenna-for-noise.html https://frugalradio.com/my-loop-on-ground-ham-antenna-worked/ https://rudys.typepad.com/files/630m-log-notes.pdf to have an idea of what to expect from such a simple...

Jock Elliott wrote: ↑Fri Sep 30, 2022 4:21 pm Wow, Andrew, just wow!

Someday, the pie and coffee are definitely on me!

Cheers, Jock

nothing special, Jock, just some hopefully useful ideas, check if one of them may be applied in practice

Jock, here are some coarse ideas which you may consider



from left to right, top to bottom; the LoG, the Marconi T, a miniwhip and an inverted L, sizes aren't to scale, just to give you an idea of the general setup

That is the same as I made my one Now I'm confused, if your support pole is 3m and your cross structure is above the pole, then the height of the bottom corner of the SULA should be about 3m from ground... then ok, you tested the SULA inside so no support pole, the antenna sits near ground and suff...