I realize that many people speak of this antenna as a Magnetic loop antenna however it is not a Magnetic loop, it is an active loop which uses an amplifier to boost the received signal. The magnetic loop does not. A properly built magnetic loop has an extrremely narrow tuned bandwidth the span of which will be dependant on the frequency of the band in which you are tuning. I believe you do a diservice to the magloop when you compare them to an active loop. I have 2 mla-30's and use them both. They are great for reducing local noise to alleviate listening fatique. I also have a 6 ft. diameter magnetic loop that compares extremely well with the ZS6KW antenna on the 40 meter band on transmit and is far superior on receive due no doubt to its noise reducing capability. On air tests found that receiving hams generally gave the edge to the magnetic loop over the other antenna. by the way, I have a 10 - 15 db over s9 noise level on the zs6bkw . The mla-30+ reduces that to around 4 S units though it also reduces the level of the incoming signal but the signal to noise ratio is ever so much better. It is also positioned much farther from any houses which no doubt helps.
Thanks for taking the time to post this comment Garry. I have done a bit of research on this and it seems you are correct. For the most part, this is not a mag loop antenna, but…. ;-) Here is what I found… -------- April 2024 Notes - Is this a “mag loop” antenna? In response to a couple of viewers who stated, “This is not a mag loop antenna”… I did some research on this… it would seem you are correct, but… Hahaha! As always, with so many things, “it depends” comes into play. On page 9.13 of the 2023 (25th edition) ARRL Antenna Book, I found a little box with a statement about the definition of a Mag Loop antenna. It references the Mar/Apr 2020 QEX technical note which defines the boundary as being where the circumference of the loop is less than .05 wavelength. This is where the electric to magnetic field ratio tips in favour of the magnetic field. In this case, a 1 meter diameter loop is considered a mag loop at frequencies below 4.8 MHz… so on 80 meters, this would be considered a “mag loop”. At 40 meters and above, it clearly does not meet the definition. --------
Many thanks for a great video, here is what i got out of it. The dipole wins every time, the use of rf gain will help sort out most of the noise floor situation. In a small place situation, one might be better using a vertical antenna. As for N/S ratio, a full-size loop will perform the best and take down most of the noise floor.
I’m going to watch for an electrically noisy day on my dipole, and then take some video comparing the performance of the mag loop versus the dipole again, with regards to signal to noise ratio. I would like to show if and how the mag loop is able to null out local sources of noise that I cannot do with the dipole. At this point, I agree that the dipole is winning. In my mind the comparison is not quite yet complete though.
Hi Gregg. Nice video for comparison. Just a comment on how to show the peak, noise floor, and SNR on the SDRSharp screen. If you place the cursor on the center frequency in the upper spectrum window, SDRSharp will show the received signal parameters. It might also be helpful for comparisons to switch the HF+ Discovery sampling rate and/or spectrum window width to show a wider swath of frequencies. Also, when you first go outside at 02:00 in the video, the loop is oriented with its plane in the horizontal. With my limited experience with loops, the poorest reception is with the plane of the loop oriented horizontally. In fact, once you 'rotate' the loop into a vertical plane between 02:02 and 02:08 the signal levels pick up, and drop considerably when you rotate the loop back into the horizonal plane at around 02:10. After 02:13 until 02:37 when the loop plane is vertical again, signals pick back up. The "brightest" peak in the waterfall appears at about 02:15, and you can see peaks and dips as you rotate the loop throught the vertical plane, as would be expected with a loop antenna. Based on your QTH coordinates as listed on QRZ.com, WWV should be at a Great Circle bearing of 140.8°, or southeasterly. Thus, one might anticipate the highest signal from the loop if oriented vertically and the support rod pointed in a southeasterly direction. At about 02:34, you make the comment that orientation is about the best you can get, yet the waterfall seems to show a signal dip at that time. Perhaps it was fading going on, or your Black Lab was blocking the signal as it walked by, hi hi. My point is, that when you started your outside tests, the plane of the loop was oriented horizontally, and if you returned it to a horizontal orientation for your comparisons then it might not have performed as well as could be expected. It will never compare to the dipole, but you might be able to squeeze a bit more performance out of it with proper orientation and rotation. If you have a local noise source, turning the loop to null out the noise, as opposed to peaking the desired signal might be your best bet. You allude to that in your last reply to ThinFreddysFlop from 10-days ago. Again, great video. Keep up the good work, and good DXing. 73. Ken -- WBØOCV
Thank you for sharing these thoughts. I will go mess with the SDRsharp software and see if I can get it to tell me S/N ratio of a signal. Sometimes I will intentionally set the loop for minimum signal and maximum noise to feed the ‘noise’ input of a phase type noise canceller. That may have been why you initially saw the antenna oriented this way :-)
Gregg, I like your video, but I think you are being unfair with the MLA-30+. Given its almost nothing price ($28 delivered), its a stellar performer. If you mount antenna to a $120 RCA TV remote controlled antenna rotor, you will be very impressed with its ability to dig out weak signals. I use a wire antenna to detect their presence on a wire antenna connected to my SDR Play receiver. Then I zero into it with my MLA-30+ rotated to the optimal azimuth angle. Connected to my AOR 7030 shortwave desktop receiver or my Drake R-8, I get fantastic results at a nominal cost. BTW, I have gotten the best results powering my MLA-30+ with a Samsung or LG cellphone USB charger. Other cellphone chargers inject too much noise either through the wires or RF-wise.
Thank you for the comments. There has been speculation that I may have gotten a poor quality copy of this antenna. I have since ordered an LZ1AQ pre-amplifier kit, and have built one of the recommended configurations using two loops. It does seem like it’s able to rival the full length inverted V on 80 m so far. I have a lot more playing around to do but initially I am pretty impressed with it. I do agree that for the price, the MLA 30+, even if I have a poor quality copy, does pretty good given its size and price.
Yes, there are a lot of cheap MLA-30 knockoffs out there, and I guess I just got lucky my two MLA-30+ purchases. But regardless what remote rotator you use, the RCA one on Ebay does the job well at a fraction of what a HAM styled rotator costs. I bought a remote 30 dollar TV rotator recently. Once I weatherize it for outside use, I plan to mount it on a spot on my wooden fence.
I installed two V antennas in my backyard and I am happy with them. One has RF traps and the other does not. But the 3 loops I use are still less noisey than my Vs.
Open it up. There are gain and attenuation pots you can adjust for optimization in both the bias-t and the lna. You might have some luck with that, might not.. depending on how they set it at manufacturing.
I have not done that comparison, but… so far the mag loop has in only one circumstance performed better than my inverted vee dipole.. when I had a local noise source that was S9+ on the dipole and I was able to orient the loop to use the null point to minimize the noise. In all other circumstances, the dipole gave better overall signal levels and better signal to noise ratio. Based on my observations, I would expect that the long wire would perform better in all conditions, except where you have a very strong local noise source.
Looking at your copy of the MLA-30+ it seems that yours is a knock off, Gregg. The genuine one is less noisy than counterfeit ones. I learned that my first purchase was a knock off when the LNA module which was shipped to me has four screw holes and not six. The metal wire for the loop is much longer (larger diameter) than the original version, it kinks in places and is impossible to form a perfect circle. In addition, no Philips screws were provided with the kit. The bias tee box came with a red LED instead of bright green. I did a quick and simple test myself at home by swapping the bias tee box (green LED) that came with the genuine MLA-30+ kit with the bias tee from the fake kit (red LED). The noise floor is higher with the fake bias tee unit. I had also experimented using the genuine bias tee with the fake MLA-30+ LNA and got similar results. I guess the manufacturer of the knock off kit used substandard electronics components in both the bias tee box and the LNA module. The radio receiver which I used for my simple experiment was an RTL-SDR Blog V3 USB dongle and I used the Android version of the SDR++ software running on a 10.4" Huawei tablet. I have since bought a Malahit DSP1 clone standalone SDR, an RTL-SDR BLOG V4 and an AirSpy HF+Discovery but have not repeated the experiment with both MLA-30+ antennas. I will still keep the knock off MLA-30+ and intend to use it with my Tecsun and XHDATA radios. It does pull in faint signals much better than the passive wire reel antennas which I have used for years, but the genuine MLA-30+ kit is the best HF antenna that I have at the moment. 🙂
@@ve6wo This is definitely an inferior knock-off. I know because I also received a knock-off when I ordered an MLA-30+. In addition to the characteristics listed by Stratmanll (mounting case with 4 holes instead of 6 and a longer, bent wire antenna), the "biasing tee" box for a knock-off often does not have a hole for the LED light to shine through, and the label is often upside-down compared to a genuine "biasing tee" box. A genuine "biasing tee" box has a green LED, while an inferior knock-off typically has a red LED.
I realize that many people speak of this antenna as a Magnetic loop antenna however it is not a Magnetic loop, it is an active loop which uses an amplifier to boost the received signal. The magnetic loop does not.
A properly built magnetic loop has an extrremely narrow tuned bandwidth the span of which will be dependant on the frequency of the band in which you are tuning. I believe you do a diservice to the magloop when you compare them to an active loop. I have 2 mla-30's and use them both. They are great for reducing local noise to alleviate listening fatique. I also have a 6 ft. diameter magnetic loop that compares extremely well with the ZS6KW antenna on the 40 meter band on transmit and is far superior on receive due no doubt to its noise reducing capability. On air tests found that receiving hams generally gave the edge to the magnetic loop over the other antenna.
by the way, I have a 10 - 15 db over s9 noise level on the zs6bkw . The mla-30+ reduces that to around 4 S units though it also reduces the level of the incoming signal but the signal to noise ratio is ever so much better. It is also positioned much farther from any houses which no doubt helps.
Thanks for taking the time to post this comment Garry. I have done a bit of research on this and it seems you are correct. For the most part, this is not a mag loop antenna, but…. ;-)
Here is what I found…
--------
April 2024 Notes - Is this a “mag loop” antenna?
In response to a couple of viewers who stated, “This is not a mag loop antenna”…
I did some research on this… it would seem you are correct, but… Hahaha! As always, with so many things, “it depends” comes into play.
On page 9.13 of the 2023 (25th edition) ARRL Antenna Book, I found a little box with a statement about the definition of a Mag Loop antenna. It references the Mar/Apr 2020 QEX technical note which defines the boundary as being where the circumference of the loop is less than .05 wavelength. This is where the electric to magnetic field ratio tips in favour of the magnetic field.
In this case, a 1 meter diameter loop is considered a mag loop at frequencies below 4.8 MHz… so on 80 meters, this would be considered a “mag loop”. At 40 meters and above, it clearly does not meet the definition.
--------
Many thanks for a great video, here is what i got out of it.
The dipole wins every time, the use of rf gain will help sort out most of the noise floor situation.
In a small place situation, one might be better using a vertical antenna.
As for N/S ratio, a full-size loop will perform the best and take down most of the noise floor.
I’m going to watch for an electrically noisy day on my dipole, and then take some video comparing the performance of the mag loop versus the dipole again, with regards to signal to noise ratio. I would like to show if and how the mag loop is able to null out local sources of noise that I cannot do with the dipole. At this point, I agree that the dipole is winning. In my mind the comparison is not quite yet complete though.
Hi Gregg. Nice video for comparison. Just a comment on how to show the peak, noise floor, and SNR on the SDRSharp screen. If you place the cursor on the center frequency in the upper spectrum window, SDRSharp will show the received signal parameters. It might also be helpful for comparisons to switch the HF+ Discovery sampling rate and/or spectrum window width to show a wider swath of frequencies.
Also, when you first go outside at 02:00 in the video, the loop is oriented with its plane in the horizontal. With my limited experience with loops, the poorest reception is with the plane of the loop oriented horizontally. In fact, once you 'rotate' the loop into a vertical plane between 02:02 and 02:08 the signal levels pick up, and drop considerably when you rotate the loop back into the horizonal plane at around 02:10. After 02:13 until 02:37 when the loop plane is vertical again, signals pick back up. The "brightest" peak in the waterfall appears at about 02:15, and you can see peaks and dips as you rotate the loop throught the vertical plane, as would be expected with a loop antenna. Based on your QTH coordinates as listed on QRZ.com, WWV should be at a Great Circle bearing of 140.8°, or southeasterly. Thus, one might anticipate the highest signal from the loop if oriented vertically and the support rod pointed in a southeasterly direction.
At about 02:34, you make the comment that orientation is about the best you can get, yet the waterfall seems to show a signal dip at that time. Perhaps it was fading going on, or your Black Lab was blocking the signal as it walked by, hi hi. My point is, that when you started your outside tests, the plane of the loop was oriented horizontally, and if you returned it to a horizontal orientation for your comparisons then it might not have performed as well as could be expected. It will never compare to the dipole, but you might be able to squeeze a bit more performance out of it with proper orientation and rotation. If you have a local noise source, turning the loop to null out the noise, as opposed to peaking the desired signal might be your best bet. You allude to that in your last reply to ThinFreddysFlop from 10-days ago.
Again, great video. Keep up the good work, and good DXing. 73. Ken -- WBØOCV
Thank you for sharing these thoughts. I will go mess with the SDRsharp software and see if I can get it to tell me S/N ratio of a signal.
Sometimes I will intentionally set the loop for minimum signal and maximum noise to feed the ‘noise’ input of a phase type noise canceller. That may have been why you initially saw the antenna oriented this way :-)
Gregg, I like your video, but I think you are being unfair with the MLA-30+. Given its almost nothing price ($28 delivered), its a stellar performer. If you mount antenna to a $120 RCA TV remote controlled antenna rotor, you will be very impressed with its ability to dig out weak signals. I use a wire antenna to detect their presence on a wire antenna connected to my SDR Play receiver. Then I zero into it with my MLA-30+ rotated to the optimal azimuth angle. Connected to my AOR 7030 shortwave desktop receiver or my Drake R-8, I get fantastic results at a nominal cost. BTW, I have gotten the best results powering my MLA-30+ with a Samsung or LG cellphone USB charger. Other cellphone chargers inject too much noise either through the wires or RF-wise.
Thank you for the comments. There has been speculation that I may have gotten a poor quality copy of this antenna. I have since ordered an LZ1AQ pre-amplifier kit, and have built one of the recommended configurations using two loops. It does seem like it’s able to rival the full length inverted V on 80 m so far. I have a lot more playing around to do but initially I am pretty impressed with it.
I do agree that for the price, the MLA 30+, even if I have a poor quality copy, does pretty good given its size and price.
Yes, there are a lot of cheap MLA-30 knockoffs out there, and I guess I just got lucky my two MLA-30+ purchases. But regardless what remote rotator you use, the RCA one on Ebay does the job well at a fraction of what a HAM styled rotator costs. I bought a remote 30 dollar TV rotator recently. Once I weatherize it for outside use, I plan to mount it on a spot on my wooden fence.
I installed two V antennas in my backyard and I am happy with them. One has RF traps and the other does not. But the 3 loops I use are still less noisey than my Vs.
Open it up. There are gain and attenuation pots you can adjust for optimization in both the bias-t and the lna. You might have some luck with that, might not.. depending on how they set it at manufacturing.
Thank you for that. I will take a look :-)
Hi, how does this perform compared to a long wire antenna?
I have not done that comparison, but… so far the mag loop has in only one circumstance performed better than my inverted vee dipole.. when I had a local noise source that was S9+ on the dipole and I was able to orient the loop to use the null point to minimize the noise. In all other circumstances, the dipole gave better overall signal levels and better signal to noise ratio.
Based on my observations, I would expect that the long wire would perform better in all conditions, except where you have a very strong local noise source.
Looking at your copy of the MLA-30+ it seems that yours is a knock off, Gregg. The genuine one is less noisy than counterfeit ones.
I learned that my first purchase was a knock off when the LNA module which was shipped to me has four screw holes and not six. The metal wire for the loop is much longer (larger diameter) than the original version, it kinks in places and is impossible to form a perfect circle.
In addition, no Philips screws were provided with the kit.
The bias tee box came with a red LED instead of bright green.
I did a quick and simple test myself at home by swapping the bias tee box (green LED) that came with the genuine MLA-30+ kit with the bias tee from the fake kit (red LED). The noise floor is higher with the fake bias tee unit.
I had also experimented using the genuine bias tee with the fake MLA-30+ LNA and got similar results. I guess the manufacturer of the knock off kit used substandard electronics components in both the bias tee box and the LNA module.
The radio receiver which I used for my simple experiment was an RTL-SDR Blog V3 USB dongle and I used the Android version of the SDR++ software running on a 10.4" Huawei tablet. I have since bought a Malahit DSP1 clone standalone SDR, an RTL-SDR BLOG V4 and an AirSpy HF+Discovery but have not repeated the experiment with both MLA-30+ antennas.
I will still keep the knock off MLA-30+ and intend to use it with my Tecsun and XHDATA radios. It does pull in faint signals much better than the passive wire reel antennas which I have used for years, but the genuine MLA-30+ kit is the best HF antenna that I have at the moment. 🙂
Thank you for the information.
@@ve6wo This is definitely an inferior knock-off. I know because I also received a knock-off when I ordered an MLA-30+. In addition to the characteristics listed by Stratmanll (mounting case with 4 holes instead of 6 and a longer, bent wire antenna), the "biasing tee" box for a knock-off often does not have a hole for the LED light to shine through, and the label is often upside-down compared to a genuine "biasing tee" box. A genuine "biasing tee" box has a green LED, while an inferior knock-off typically has a red LED.
@@JonAhlquist Thank you for the information.