In this video, as in several of the last videos we talk about loop antennas. But this time we take a look at a super simple way to couple any loop to you SDR. In this case we are using the HF Discovery + and Console Version 3
Interesting stuff. Two suggestions. When demonstrating try to show more closeups of what you are showing us. Otherwise the way you've constructed these things gets lost. Secondly, stand behind what you are showing not in front. Wear a contrasting color so the details of your creation are not lost. I was really interested in how you built these things but could not get a good look. Thanks for taking your time to explain all this. I am not ungrateful of your efforts.
Thanks for a very interesting video. I have wondered how to benefit my SDR by using my Select-A-Tenna and Super Select-A-Tenna as well as a few homebrew loops. This coupling technique works great!
Thanks for the interesting video. I have a homemade box type loop antenna and managed to connect my Yaesu FRG-100 using coaxial cable from the radio antenna output connection and connecting to another piece of coaxial cable via an F75 connection and draped around the loop antenna. I have also made it possible to use it with any loop antenna and even a long-wire antenna separately. You seem to go well with less noise down the lower end of the AM band. Here in Melbourne Australia, the unwanted noise is quite bad these days, especially on the lower frequencies. All the very best. Robert.
That was an amazing video, I just got a SDRPLAY RSP-DX and want it to be a powerhouse for all sw frequencies. You video was great and gave me new respect for those loop antennas I will be watching all your antenna videos. AA4CP Chuck Port Salerno FL USA
Thanks for sharing. It's a good idea. I restore and use radios but I also enjoy working with SDRs. I also use the SDR Console software that you're using. I enjoy using the portion of the software for tracking and receiving Satellite signals.
У Вас красиво работает анализатор спектра... И всё-таки на 12:21 картина отрывается целиком от "нулевой линии". Это связано с перегрузкой "автоматической регулировки усиления" или чем-то другим? Спасибо! [Москва]
This is very interesting and reminds me of the "teaser" coil in crystal radios. Would you get a stronger signal if the secondary loop (with the BNC) had several turns? Thanks for taking the time to make this.
Nicely done, OM. I like the simplicity of the test setup - allowing you to change small loops with ease and speed and let you step back and not become part of the test. I wonder what would happen if you taped a pickup loop around the main loop device so have a 1:1 pickup size? Thanks. 73 TT
I have a Drake Radio hand book written in 1931 which describes this same loose coupled tank circuit as a signal multiplier so we are not inventing the wheel here folks. 90 years ago they worked all of this stuff out with log tables, slide rules and inquiring minds.
Have you ever tried using an EMF source to transmit frequencies onto a coil? The function generator would inject the signals to the EMF source and the coil would receive the signals.
Someone who thinks like I do, and actually experiments instead of giving me a load of equations that I can't wrap my brain around. I knew this video was going to be good when I saw the high quality vice mounted on the bench :)))
I do watch this vedio multiple times. It's so informative. So bigger loop bring in more sensitivity and smaller Coupling more selectivity. Also what should one use for more sensitivity, a big loop or ferrite rod antenna.. does it make any difference if you make one end of ferrite higher than other end as I see it not perfectly horizontal in some radios
Sorry. Did not know the right place to ask this. I am trying to receive a very low power 125 kHz signal. I was wondering if you could suggest an antenna loop size and number of turns I should consider making for this purpose. I am using a Ham it up plus and an rtl-sdr v3. I am using a loop antenna I purchased from Amazon . The signal appears very weak as it should. 8 db over the noise floor of -84 db. Curious what you would suggest. Thank you for any suggestions!!
Excelente aporte 👍. Trataré en alguna oportunidad de fabricar una antena para mí olvidado SDR que nunca pude disfrutar... Gracias y saludos desde Argentina 🇦🇷👋
Hi Paul, I do have the tecsun AN-200 loop antenna (your grundig) and with the audio cable I did connect it directly to my rsp1a. I think I will get bigger signals if I use a loop like you did. Can that be true?
Paul could you couple a outside large loop antenna through a ferrite core to the smaller loop that would pass your larger loop signals to the indoor loop and then pick it up on the sdr so you could use the tuning knob for selectivity From the big loop. Probably a stupid question Chuck AA4CP
Nope not stupid at all. I have done that in a very specific case. I used the main loop tuned to a station through a twisted pair of wire, to a small coil, on top of a AM radio as you suggest. This allowed me to turn the loop in any direction with out having to move the radio. Also it allows running of a remote loop outside lets say to a radio with no external antenna connection. Try it experiment W1VLF
Great informative video. Thank you for the upload and sharing. What happens if you stack/couple all of the loop antennas in a row? Is there a better reception all around, or do they cancel out?
Everett Sharp has said that a 64:1 impedance ratio transformer between the coupling coil and receiver improves the signal transfer. Have you ever added a transformer to your coupling loops? 73, Guy
NOTE: When We Do Such Experiments And Stuff, Make Sure You Dont Wear Any Silver Or Gold Or Any Jewelry, Keep Your Phones And Everything metal Out of The Pockets Because That May Take A Effect On The Reception of The Frequencies You Are Experimenting On !
Is it possible to make a direct connection the the loop antenna? Possible as in would that work? Is inductive coupling better than making a direct connection to the loop antenna?
Steve, It would not be better to connect directly to the antenna. Here's why, When you connect directly to the antenna you load down the loop with the receiver's input impedance, say 50 ohms. So the one turn is like the primary on a transformer. This will spoil the Hi Q of the antenna an cause signals to be low and you will not be able to tune the antenna. Secondly the one turn inductive feed isolates the coax ground from the antenna to achieve better balance and nulls. W1VLF
@W1VLF thank you for the response and very good explanation. Hopefully I am gonna be able to have the time to build one soon. Just have a RTL-SDR right now. Was thinking about the RDPplay but I gonna look at the airspy since you have had such good results from ut..
@W1VLF hey brother man, I tried making my own. It is 2ft square. 15 turns of 24 gauge solid wire from lan cable and 500pf air cap. Online am loop calculator said that should work. I have only tried on my old 6 band table top radio sitting inside it. I think it makes a tiny bit of difference but nothing I can see like I have seen on other videos.... It did have a small effect. It seemed like one time I was able to make radio go from one station to a different one turning the cap. I think I accidentally made a super sharp Q. H e double hockey sticks if I know. I must have messed up somehow. Haven't done the small loop to see if it works on SDR yet.
@W1VLF update same night: Ok I slowed down. 1. Hard mounted the air cap 2. Turned off the dang noisy lights. 3. Realized I happen to build this thing on a night that is a DXers wet dream. Can't touch know without coming across a signal. Listening to a station from Chicago and I am near gulf coast SETX.
Very informative video. Thank you! One question I have is whether it would make sense to couple the receiver directly to the large loop? I’m guessing that the motivation for using the small coupling loops is to avoid needing an impedance matching network, but as you point out, the smaller loops do not take advantage of the larger signal strength available from the large loop. Am I thinking about this correctly? Thanks again.
Very interesting and informative!!!. I was wondering how can we design a metal detector search coil so that it detects a quarter size coin from a distance of 3 meters? I appreciate it if you can show us a short video about that.
The major problem with HAMS is that they assume that everyone just knows what their acronyms are. To set you straight - well - NO, we don't. So, as to all the 'secret stuff' only HAMS have any interest or knowledge in - well, sorry. Thumbs down and no subscription. If you wanted that beneficience you should have planned better.
