Reviews of the Low Cost MLA-30 Wide Band HF Magnetic Loop Antenna
Recently Chinese manufacturers have begun producing a low cost wide band (100 kHz - 30 MHz) magnetic loop HF antenna known as the MLA-30. The loop can be found on eBay for under US$45 with free shipping. In the past wide band HF loop antennas have not been cheap, normally costing $300+ dollars from manufacturers like Wellbrook.
RF signals are electromagnetic waves that consist of an electric and magnetic component. A magnetic loop antenna mostly receives the magnetic portion of the wave. This is useful as most unwanted interference from modern electronic devices is generated in the electric component only. So, a magnetic loop antenna may be preferable in city and suburban environments over other antennas like wires and miniwhips. Magnetic loops are also directional, and can be rotated to avoid interference.
One of the biggest costs to a magnetic loop antenna is the shipping, because a large hula hoop sized piece of metal needs to be sent. The MLA-30 cuts costs on shipping by providing a folded up thin loop wire and no physical support for the loop. You are expected to provide your own support, or simply hang the loop wire on something. If you like you can also replace the included loop wire with a larger loop.
The MLA-30 comes with 10m of RG174 coax, is bias tee powered, and comes as a set with a bias tee injector that is powered over 5V USB. We tested our own unit with the RTL-SDR Blog V3, Airspy and SDRplay bias tee's and found that they all worked well instead of the included bias tee. So if you have one of those SDRs using the loop is as simple and neat as plugging it in and turning on the bias tee.
In terms of build quality, the unit is sturdy and the PCB is fully potted and protected against rain/weather. It is yet to be seen how the external screw terminals holding on the loop will age over a longer period of time however.
So how does the very cheap MLA-30 compare to higher end magnetic loop antennas? Below are some reviews by various hams and SWLs. The general consensus is that it works well for the price, but as you'd expect, falters on handling very strong signals and produces a higher noise floor compared to the more expensive loops, especially in the higher HF bands. But overall we'd say that it's probably still better than using a miniwhip, especially in suburban/city environments, and is probably the best compact HF antenna that you can get on a budget.
MLA-30 Magnetic Loop Antenna Review and Comparison by David Day (N1DAY)
In this review David compares the MLA-30 against a 30-ft ground loop and a Wellbrook ALA1530-LF. His results show that while the loop is capable of receiving the same signals that the two comparison loops can, the SNR is much lower. He also notes that the much thinner loop wire used on the MLA-30 seems to result in a much deeper null, and that IMD was a problem for him.
Inside the MLA-30 Active Loop Antenna by Matt (M0LMK)
This post is a complete teardown of the antenna. As the PCB is fully potted Matt had to boil down the epoxy in order to get to the actual PCB. He notes that the PCB is a simple single amplifier design with the exposed pot working as a gain control.
Cheap Chinese Magnetic Loop Antenna (MegaLoop aka MAGALoop) MLA-30 by John
In this review John compares the MLA-30 against a $345 W6LVP and Wellbrook ALA1530LN. His findings are very favorable concluding that it is an adequate performer, perfect for cash strapped SWLs.
First hour battle of the antennas W6LVP loop VS MLA 30 loop test by OfficialSWLchannel
This is a YouTube video where OfficialSWLchannel compares his MLA-30 against a W6LVP loop. He notes that his initial testing shows that the MLA-30 performs as well as the W6LVP loop.
MLA-30 Loop vs 80M EFHW by Matthew Payne
In this YouTube video Matthew compares his MLA-30 against a 80M end fed halfwave antenna with an SDRplay RSP1a.
MLA-30 Magnetic Loop Modifications by Scanner and Sdr Radio
In this video the Scanner and Sdr Radio YouTube channel uses an RSPduo to compare the MLA-30 against a Wellbrook loop. His results show that the MLA-30 definitely has a higher noise floor compared to the Wellbrook, but still receives signals decently although chasing weak signals it's not good enough. He also shows how to improve the MLA-30 by replacing the cheap coax that it comes with, noting that the modification reduced his noise.
If anyone stil reads this, there is a MLA-30Plus version with better performance on the higher frequencies
So instead of using the included Bias Tee. I can just plug the SMA coax in to my RSP1A? ( Direct connect, not using the bias tee )
Connect direct to the RSP1a without the hardware Bias-T
Just activate the bias T in SDR Uno software and you are good to go
How is this possible? The output of the V3 bias-T is 5V and the output of the included bias-T box is 12V. I tried using the V3 bias-T with this antenna just now and it doesn’t power it. I have to use the bias-T box that came with the antenna. Did they change the design?
Disregard my previous comment. Turns out that using the rtl-biast batch files would turn on the bias-t on the V3 but wouldn’t power on the MLA-30 for some reason. However, when I turn on the V3 bias-t using SDR-Console program, it works. So I am not sure what the SDR-Console program is doing differently when turning on the V3 bias-t but that’s the only way I can power the MLA-30 with the V3 bias-t.
How can i connect the loop to a tecsun 660? i need a 3.5 jack adapter. right? It’s included?
Yeah. I am having the same question to myself! I also have a PL660!
So well, me supposed and published few day ago, this piece of info to M0LMK discuss boar. But was not approved. So sorry.
Also discuss on website Czechoslovak DX club
Me built “Hula Loop” antenna, from kit on ebay.com Similar to this one project :
Must agree with you IC is TL592 or NE592. Depending on factory production.Yes exist also LM733 “video amplifier” but there is another one pinout.
I suggest these mods.
Install BNC connector to ABS box.
Using low loss coax. cable better than RG-174 is a necessary.
For “Heavy Duty” installation is a better replace loop wire by bicycle rim (average 600mm)
Using linear power supply instead powering from “hummy” USB port.
GL 73! Ladislav OK1UNL
MLA-30 circuit diagram and test results at:-
Nice test Martin, thank you. It proves that you get what you pay for. I will still be going for the W6LVP loop later this year.
Thanks for putting all of this info about it in one place. I’ve been considering getting one of these loops and from what I’ve read so far as long as I replace the coax they supply with something better I should be satisfied with it.
I bought half a dozen type f – sma adapters from ebay, couldn’t find any locally, sure come in handy.
I purchased the MLA-30 the same day OfficialSWLchannel placed his order. Transaction was normal with an ETA but did not receive a tracking #, although it showed up on time, just as advertised. I built it that day and was receiving strong signals that night. It was just what I was looking for for my Realistic DX-440. I have a 60 ft end fed wire antenna and now the MLA-30 also. Much expanded bandwidth coverage from the MLA-30.
I would never spend $300 + on an antenna for my use. If I win the Lottery and invest in serious equipment, then ill be in the market for something larger. I was starting to make plans to build my own Loop, but seriously lack the know how and/or Time. Once I saw this, I figured the hard part is done.
I was surprised at the Mini Coax connections and cables that came with it. I didn’t pay close enough attention to the specs. I need some adapters to kick it up to some standard sized Coax and try that on for size.
I also like the Idea of replacing the thin “loop wire” with some thicker copper. Thats an experiment for another day. Its not for everyone, but it fits my needs and may be a stepping stone to other things.
With Bangood you have to use Paypal.
If you have problems, immediately open a dispute on Paypal.
Speaking with Bangood is a waste of time.
What does “active receiving antenna means?…. is it tuned for transmitting too?
No, this is basically an amplified receiving loop. If you transmit into it, you will fry the amplifier.
Most antennas just sit there and receive the signal. Those are called “Passive” antennas. When an antenna or it’s accessories actually process the signal in some way they are called “active” antennas. Processing is usually simply amplifying the signal, but some can also employ signal processing by notiching out unwanted signals.
More commy junk, a fool is easily parted of thier money while undermining thier own countries business and adding to landfill.
Funny how a commy country is the one is democratizing radio access for everyone in the world. This is all that most people can afford.
But in this case they’ve designed some “junk” that actually makes it possible for someone to buy a decent loop antenna that compares close to the way $300-$600 loop antennas perform. Not quite as good, but good enough that people that might never be able to shell out hundreds of dollars more might be able to enjoy a much cheaper version that compares somewhat favorably to those high priced Wellbrooks and etc.
I most certainly appreciate the productive capacities of the Chinese proletariat. Once unaffordable products for the lower tier income people of the USA are now easily within their reach. Your ideology is not addressing the economic injustice that the commies are, and beating american capitalists at their own game. I must consign your unfair, and parasitic ideology to the landfill.
Yeah- probably time to shelve the 60’s attitudes about China. You may not like the politics, but they’re currently beating the world at capitalistic-based economics, with no signs of stopping. Why? Because their factories are built with stop-on-a-dime diversification in production.
Careful with aliexpress, I’ve done 2 total transactions with them and both times my CC info was compromised. And once someone somehow used my paypal info to buy something and have it delevered in china. It was a low cost item and they quickly refunded my paypal when i complained, but still, it was very weird. I’d avoid them. YMMV
I’m not doubting that this happened, but I raally doubt that Aliexpress had anything to do with it. Alibaba are one of the biggest online shopping sites in the world, and the actual vendor never gets your CC info. I get that to some people China=sketchy, but since you mention Paypal also, I would venture that your online opsec needs some work. You probably have some other compromise you aren’t aware of.
Yea, I have done countless orders on AliExpress and not had any issues!
Any chance of a non-Ebay purchasing option (perhaps via the RTL-SDR.com store)? I abandoned rip-off bay years ago and will never go back.
Have you tried banggood?
Avoid Banggood. They used to be OK . Ordered a drone they had on special offer recently. They sent an empty box. Won’t make good because I can’t produce a video of me opening the shipping bag or an ‘official’ document from the post office specifying the weight of the parcel they delivered.
Thanks Bill and Gerry – I totally forgot about these two options for sourcing China stuff!