Loop Experiment "LIL" Low Impedance Loop


Paul Cianciolo
 

Hello All
Try one of these on for size... "LIL"  Low impedance Loop by W1VLF
Solid copper tubing, no preamp, exceptional nulls, no tuning, adjustable tilt. 
Build one yourself..

https://youtu.be/jaT4-PkxYqo

W1VLF


Joshuah Rainstar <joshuah.rainstar@...>
 

I like the concept. That is to say, I deeply enjoy transformer-coupled balanced traveling wave loop design.
But I really wonder what the performance of this loop is, and now that we all have mini vna devices a decent sweep seems obligatory.
He mentions using three type 75 cores, the so-called x59 series. It should be noted these are out of stock, but would work well for VLF to about 5 mhz. 
This is equivalent to a neosid core 28-744C36. Ferronics and ferroxcube do not make cores of the right sizes in a similar material.

He talks about having good nulls and being able to rotate them. The youloop nulls are nowhere as sharp, because the feedline
is part of the antenna, because there is no isolation between the antenna and the 2 meter section running to the receiver at all.



On Sat, Feb 20, 2021 at 4:45 PM Paul Cianciolo <paulc@...> wrote:
Hello All
Try one of these on for size... "LIL"  Low impedance Loop by W1VLF
Solid copper tubing, no preamp, exceptional nulls, no tuning, adjustable tilt. 
Build one yourself..

https://youtu.be/jaT4-PkxYqo

W1VLF


prog
 

I confirm this concept definitely works and was also tested in the early YouLoop experiments by Leif SM5BSZ and myself in 2017. A transformer with one turn primary built with a large copper scrap and a multi-turn secondary that feeds a high impedance JFET preamp. Check the video for the details:
https://m.youtube.com/watch?v=MNfc09SwwX8
There is no reason it shouldn't work with one turn loop like in the LIL. The body of the loop is just one turn primary and the ferrite ring completes the transformer. In the end, the output will be high-z and will leverage the front-end of the Discovery. A JFET preamp will be needed for other receivers. 


Paul Cianciolo
 

Hi Prog,

 

Thanks for that link..  I had not seen that before.. Leif does great work in his videos, and he a regular guy.. He is one of the guys that inspired me to get off my butt and do some YT videos.  He believes, as I do, in function over fashion. No fancy salesmanship in my videos.. LOL

 

Thank you again sir for all your great work and  products.

 

 

PaulC

W1VLF

 

Check out my  Youtube Channel W1VLF

 

 

From: airspy@groups.io [mailto:airspy@groups.io] On Behalf Of prog
Sent: Sunday, February 21, 2021 8:54 AM
To: airspy@groups.io
Subject: Re: [airspy] Loop Experiment "LIL" Low Impedance Loop

 

I confirm this concept definitely works and was also tested in the early YouLoop experiments by Leif SM5BSZ and myself in 2017. A transformer with one turn primary built with a large copper scrap and a multi-turn secondary that feeds a high impedance JFET preamp. Check the video for the details:
https://m.youtube.com/watch?v=MNfc09SwwX8
There is no reason it shouldn't work with one turn loop like in the LIL. The body of the loop is just one turn primary and the ferrite ring completes the transformer. In the end, the output will be high-z and will leverage the front-end of the Discovery. A JFET preamp will be needed for other receivers.