Hi Gregg, a suggestion... Instead of metal nails into frozen ground (i.e. highly conductive!), Try using plastic stakes. You may need to drill a few holes into the frozen ground, but I think you may find the nails are inducing the ground noise. I can't really duplicate your issue here in the desert - haha...😆 73
Great video. I have known of the impedance transformation using a transformer, but this is the first time I have ‘seen’ it in action. The NanoVNA “sees” the 300 ohm load as 43.6 ohm load.
I had similar issues with the loop in my front yard but yielded better results with the loop in the backyard. I suspect it's related to the underground hydro and CATV running under the front of the property.
Wow, I didn’t realize those QRM eliminators worked so well. They really are an ingenious method of eliminating that RFI. Bose Audio Company would be proud. I may just have to pick one of those up for my shack. Nice way to salvage what would otherwise have been a really bad LoG antenna, hehe. BTW, you could have achieved a 2:4.9 ratio on that xfmr by doing a 20:49 winding, but I’m sure you already knew that, and I’m sure it wouldn’t make much difference one way or the other.
Gregg ... Nice video coverage and method reviewing your results Sir! I too tried this same type of loop at my location and came to the same conclusion as you. I do have a noise canceller that I think I might give a spin in the future. Thanks again! 73 - KF6IF
That’s neat to hear! I thought I was special… hahaha! The only one who has a loop on the ground noise magnet, when everyone else who tries it has amazing low noise receive… 😂
Very good. We are also battling similar noise and have similar tool. The video I saw he had the loop 1 foot above the ground for the most part. I was going to suggest a magnetic loop antenna for my friend. Also loop just above the ground. We are trying CM chokes and ferrites. noise not from his house, we tested. I have a VK5 noise canceller and will also take that to him to try there. Here it's not quite as bad. S 0.5 on sideband but at his it is S7 ! We were wondering if it had to do with smart meters but at mine it seems like a noisy power pole transformer. I believe that 2x turns in a binocular is simply through and back. I think it's the same with a toroid. Whenever a wire passes through the hole it's counted as one turn. I tried with a random long piece of wire in the trees at mine to use it as the Aux cancellation antenna but it only seemed to work on noises from within my house. I'm thinking I have to get the aux antenna closer to the power lines, perhaps just close to where the main power comes into the house or any power point. I could take a live wire and wrap it around the aux antenna perhaps. Ideally I need to find all the noisy transformers but I doubt they will change them here in France.
just seeing this nice video today, did you ever find the source of that QRM as heard on your Loop on the Ground? Was there a power line running right over the LoG maybe, thus inducing all that QRM directly into it?? None the less, your perfect QRM receptor sure worked well as the null'ing source against you Primary antenna, congrats !!
Yes. I was able to track down the source. It was coming from two arcing insulators atop two power poles in the back alley. I was able to use a VHF/UHF yagi and my FT-857D on battery to listen using AM demodulation to locate the poles, and then used the MFJ ultrasonic dish to pinpoint the offending component on each of the poles. The local power company came out and replaced both the failed insulators and my powerline noise issue is now gone :-) The LOG antenna just didn’t do what I needed at my location. There are many positive experiences posted online regarding this antenna, however, so perhaps it’s just one of those things where what works for one operator may not for another, depending on circumstances unique to each QTH.
Yes, that little noise cancelling box works pretty good when fed a good noise source to phase the actual receive antenna against. It’s not a full cure for noise though, you are having to constantly fiddle with it, and the receive levels after noise cancelling are not as good as taking the signal straight off the receive antenna. Perhaps a better quality unit would offer increased performance. I was looking at the DX Engineering NCC-2 at one point, but I no longer need it. www.dxengineering.com/parts/dxe-ncc-2?seid=dxese1&gclid=Cj0KCQiA1p28BhCBARIsADP9HrPa72Qu_zjT8Tu5XEq6Ay4MobAu-wV6v3H-r-m26SS-pM0-KPPo_DsaArL5EALw_wcB
Great video. It is especially difficult to imagine how much is 5/16 or 15/32 or similar. it is much easier to have millimeters, it is easier to visualize and compare
great info how ever you need to add common mod balun the noise you getting is from non adding common mod balun I had the same issue however after adding the common mod balun all noise a re gone I hope this will help you vy 73 elan
If I reassemble this antenna in my front yard at a future date, I will try a common mode choke and see what happens. I have a suspicion, however, that the type of antenna and transformer being used in this project makes it naturally resistant to common mode noise. Thanks for the suggestion :-)
I’m confused, why are you looking at matching the coax 50 ohm *impedance* with just the resistive part of the impedance of the LoG antenna? I’m wondering why you didn’t add that to your callcs for the antenna impedance. Or was it a small enough capacitance that it didn’t matter?
This is a non-resonant receive only antenna intended to be used for broadband reception. If I were to correct the reactive component as measured at a given frequency, that correction will be valid for a single frequency only and would compromise performance across the rest of the spectrum.
Good video, Gregg. My video on the LoG was among the first on You Tube and I have been using it for several years with very good success. That said, it was NOT a success at my late father's QTH, as a pesky noise source rendered the LoG ineffective. Your video echoes his experience with this design. The LoG is certainly an antenna worth trying, but as in life, there are no guarantees. Thank you for posting this (to give the other side of the coin) and 73! de WX0V
Hi Gregg, a suggestion... Instead of metal nails into frozen ground (i.e. highly conductive!), Try using plastic stakes. You may need to drill a few holes into the frozen ground, but I think you may find the nails are inducing the ground noise.
I can't really duplicate your issue here in the desert - haha...😆
73
It’s worth a shot!
Any updates on the noise source and/or elimination?
Great video. I have known of the impedance transformation using a transformer, but this is the first time I have ‘seen’ it in action. The NanoVNA “sees” the 300 ohm load as 43.6 ohm load.
I had similar issues with the loop in my front yard but yielded better results with the loop in the backyard. I suspect it's related to the underground hydro and CATV running under the front of the property.
Curious to see if the loop on the ground would be more effective if you were comparing it to a vertical antenna. Thank you for the video.
Wow, I didn’t realize those QRM eliminators worked so well. They really are an ingenious method of eliminating that RFI. Bose Audio Company would be proud. I may just have to pick one of those up for my shack. Nice way to salvage what would otherwise have been a really bad LoG antenna, hehe.
BTW, you could have achieved a 2:4.9 ratio on that xfmr by doing a 20:49 winding, but I’m sure you already knew that, and I’m sure it wouldn’t make much difference one way or the other.
Gregg ... Nice video coverage and method reviewing your results Sir! I too tried this same type of loop at my location and came to the same conclusion as you. I do have a noise canceller that I think I might give a spin in the future. Thanks again!
73 - KF6IF
That’s neat to hear! I thought I was special… hahaha! The only one who has a loop on the ground noise magnet, when everyone else who tries it has amazing low noise receive… 😂
Very good. We are also battling similar noise and have similar tool.
The video I saw he had the loop 1 foot above the ground for the most part.
I was going to suggest a magnetic loop antenna for my friend. Also loop just above the ground. We are trying CM chokes and ferrites. noise not from his house, we tested. I have a VK5 noise canceller and will also take that to him to try there. Here it's not quite as bad. S 0.5 on sideband but at his it is S7 ! We were wondering if it had to do with smart meters but at mine it seems like a noisy power pole transformer.
I believe that 2x turns in a binocular is simply through and back. I think it's the same with a toroid. Whenever a wire passes through the hole it's counted as one turn.
I tried with a random long piece of wire in the trees at mine to use it as the Aux cancellation antenna but it only seemed to work on noises from within my house. I'm thinking I have to get the aux antenna closer to the power lines, perhaps just close to where the main power comes into the house or any power point. I could take a live wire and wrap it around the aux antenna perhaps. Ideally I need to find all the noisy transformers but I doubt they will change them here in France.
I will have to go back and examine the way I wound the binocular core!
just seeing this nice video today, did you ever find the source of that QRM as heard on your Loop on the Ground? Was there a power line running right over the LoG maybe, thus inducing all that QRM directly into it?? None the less, your perfect QRM receptor sure worked well as the null'ing source against you Primary antenna, congrats !!
Yes. I was able to track down the source. It was coming from two arcing insulators atop two power poles in the back alley. I was able to use a VHF/UHF yagi and my FT-857D on battery to listen using AM demodulation to locate the poles, and then used the MFJ ultrasonic dish to pinpoint the offending component on each of the poles. The local power company came out and replaced both the failed insulators and my powerline noise issue is now gone :-)
The LOG antenna just didn’t do what I needed at my location. There are many positive experiences posted online regarding this antenna, however, so perhaps it’s just one of those things where what works for one operator may not for another, depending on circumstances unique to each QTH.
Yes, that little noise cancelling box works pretty good when fed a good noise source to phase the actual receive antenna against. It’s not a full cure for noise though, you are having to constantly fiddle with it, and the receive levels after noise cancelling are not as good as taking the signal straight off the receive antenna. Perhaps a better quality unit would offer increased performance. I was looking at the DX Engineering NCC-2 at one point, but I no longer need it.
www.dxengineering.com/parts/dxe-ncc-2?seid=dxese1&gclid=Cj0KCQiA1p28BhCBARIsADP9HrPa72Qu_zjT8Tu5XEq6Ay4MobAu-wV6v3H-r-m26SS-pM0-KPPo_DsaArL5EALw_wcB
Great video. It is especially difficult to imagine how much is 5/16 or 15/32 or similar. it is much easier to have millimeters, it is easier to visualize and compare
Great video!
I like any program that take up the issue of Nano vna😊😊😊😊😊😊😊
Are you mastering your videos in HDR?
I’m not that technical with the videos. They are shot using my iPhone 13 Pro, edited on the phone using iMovie, and then uploaded to TH-cam.
great info how ever you need to add common mod balun the noise you getting is from non adding common mod balun I had the same issue however after adding the common mod balun all noise a re gone I hope this will help you vy 73 elan
If I reassemble this antenna in my front yard at a future date, I will try a common mode choke and see what happens.
I have a suspicion, however, that the type of antenna and transformer being used in this project makes it naturally resistant to common mode noise.
Thanks for the suggestion :-)
I’m confused, why are you looking at matching the coax 50 ohm *impedance* with just the resistive part of the impedance of the LoG antenna? I’m wondering why you didn’t add that to your callcs for the antenna impedance. Or was it a small enough capacitance that it didn’t matter?
This is a non-resonant receive only antenna intended to be used for broadband reception. If I were to correct the reactive component as measured at a given frequency, that correction will be valid for a single frequency only and would compromise performance across the rest of the spectrum.
i put it 2 meters up and defased it with a rod antenne on a corner , -135 dBm noise floor , at night 80 m perfect , daytime 20 , 40 meter ok.
Good video, Gregg. My video on the LoG was among the first on You Tube and I have been using it for several years with very good success. That said, it was NOT a success at my late father's QTH, as a pesky noise source rendered the LoG ineffective. Your video echoes his experience with this design. The LoG is certainly an antenna worth trying, but as in life, there are no guarantees. Thank you for posting this (to give the other side of the coin) and 73! de WX0V
Thank you for taking the time to leave this comment. I appreciate it.