receiving loop shortwave
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- čas přidán 11. 09. 2024
- demo of a small 30 cm receiving loop for shortwave.
With the loop s/n ratio is much better compared to the whip antenna of the Tecsun PL680.
The design is very simple, just a piece of coax. Inner conductor and braid are soldered together. The tuning cap is 2x 450 pF.
Tuning range 6-15 MHz. For the lower HF bands extra capacitors can be added. For 3.6 MHz I'm using 1.9 nF.
The coax to the radio is soldered directly to the loop.
73, PA3BYW
Many people asked me about this magnetic loop. The idea is really simple. Just bent a piece of coax into a loop. A variable capacitor (2x 450 pF in paralel) is connected between the ends of the loop. This works fine for 6-15 MHz. If you want to cover the lower HF bands, just add more capacitance between the two ends of the loop. In my case I had to add 1.9 nF (nano Farad) to peak the loop on the 80m ham band. It is a matter of trial and error, just see if you can find a noise peak on the frequency of your choise by turning the variable capacitor.
The loop has a very low impedance (
Thank you very much for sharing your inspirational video. 73!
Já sacou o diagrama disso? Intrigante não ter potência eléctrica 🧐
@@DXPedro no la necesita. Las antenas comunes recogen la señal de radio principalmente del componente eléctrico, pero en las loop, es el componente magnético el predominante, por eso tienen mejor relación señal-ruido y además son directivas, permitiendo anular o bajar la fuente de ruido eléctrico.
@@marcosmza1962 gracias por contestarme 👌🏼 sabes donde puedo sacar el diagrama o algo donde pueda hacerme una antena igual?
Gracias e 73!!
Hello highwayrider66,
the variable capacitor is in parallel with the loop. In parallel with the variable capacitor I can connect aditional capacitors for the lower shortwave bands. In my case the variable capacitor's max value is about 2x450pF and I'm using about 1.9 nF for the 80m Hamband. I used a few silver mica capacitors which I had lying around but a ceramic one will be fine.
1.9nF is not a common value so you could use 1.5nF with 390pF in parallel. Or 1.8nF plus 100 pF etc.
BTW nowadays I'm using a toroid for the connection to the receiver. About 25 windings on a ferriet core and one end of the loop through the hole of the core.
pa3byw b
Why you changed to feeding through a ferrite core instead of direct feeding? Any particular advantage or reason? Thanks
pa3byw was
pa3byw did
Nice demonstration, but we want to see you make it and diagrams. Also, talking and explaining it is better than just watching you turn a knob.
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More Info, please. How is the variable capacitor wired in to the loop? And what are those red things at the back of the loop? What are their values? How are they wired in to the loop. Would like to know more if I'm to replicate this loop!
I'm too. Please Share This informations with us.
He wrote details about capacitor values and the way he choosed to connect the components 🤷🏻♂️
Usually the capacitor is connected to the two ends of the loop. An AM wire antenna video or DIY AM antenna page can show you. This is a basic AM antenna design, but with a single loop using a special type of coaxial wire.
can you post a simple diagram?
I would like to buy a kit to build this. The parts I see aren't available, except for a heavy 6 GA. cable, and the cable clamps.the socket to the extra capacitor is separate, but is electrically connected in the same way.
Can you supply instruction, I dont know where all the wires and connections go
I tinkered with this antenna one day impossible to get it going no diagram no information I see not the inters of making videos like its
many thanks for this Video
Too bad, this video is in poor resolution.
Unfortunately, I can not see any exact details.
a simple circuit diagram would be handy??
It looks like a basic tuned loop, using heavy wire or coax instead of tubing, and a fancy socket to add an extr5a capacitor.
good diagnosis interesting therapy
the curse now lifted by a wizard.