HFU HF Underground
Technical Topics => Equipment => Topic started by: alpard on July 10, 2020, 0739 UTC
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I came across this vid on youtube, and was surprised to hear that MLA-30 is better performing than all other Active Loops in the market.
The presenter says that it is better than 10 times more expensive Wellbrook? Could it be the case?
https://www.youtube.com/watch?v=k4G71UrANtA
https://www.youtube.com/watch?v=NB8RBEI-1xk
W6LVP vs. MLA-30
https://www.youtube.com/watch?v=GNN6T4C4dRk
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Anyway with the support of the review videos, I have placed an order for a MLA-30 today.
Hopefully it will be here soon.
Meanwhile I have got a Tecsun Active Loop for indoors only.
It comes with a radio stand and a few antenna connectors, and the wire loop with the amp, and tuning control box.
It works great on MW, but not good on LW.
It works weirdly on SW.
It pulls a few different signals when the tuning knob is turned.
I thought it might be the cross modulation / ghost signals again?
But I managed to tune the signal I was looking for after a few seconds of tuning about.
I don't know if it is the way it should work.
I managed to hear very weak Radio Korea signal in reasonable strength.
It performed similar to my outside LW.
It is a good value if you are after the radio stand and also a few antenna connectors, because they are very handy thing to have.
It was 39.95 EURO. So it was reasonable price.
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I came across this vid on youtube, and was surprised to hear that MLA-30 is better performing than all other Active Loops in the market.
The presenter says that it is better than 10 times more expensive Wellbrook? Could it be the case?
That seems highly doubtful.
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I came across this vid on youtube, and was surprised to hear that MLA-30 is better performing than all other Active Loops in the market.
The presenter says that it is better than 10 times more expensive Wellbrook? Could it be the case?
That seems highly doubtful.
I was taken back at the claims, but the channel seems doing reviews from his personal uses and experiences on these devices, not funded or sponsored by the device manufacturers.
I sussed it out because of his various video reviews on XHDATA D-808 receiver. He claims the D-808 is the best SW receiver in 2019 too, and he still seems swear by it.
I bought a XHDATA D-808 myself, and I too was quite impressed & satisfied with its performance. I concluded that his reviews on the D-808 have been all very accurate and factual.
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Hey, if someone wants to send me a MLA-30 I'll be happy to put it up against my Crossed Parallel Loop with LZ1AQ amplifier ;D
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I’ll stick with my W6LVP.
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I sussed it out because of his various video reviews on XHDATA D-808 receiver. He claims the D-808 is the best SW receiver in 2019 too, and he still seems swear by it.
I bought a XHDATA D-808 myself, and I too was quite impressed & satisfied with its performance. I concluded that his reviews on the D-808 have been all very accurate and factual.
How is "best SW receiver in 2019" defined? Best in the category of circa $100 portables? It could well be (I have no experience). Best radio you can buy in 2019, even compared to ham rigs and SDRs? Not so sure. :D
Not knocking what works for you, of course, everyone has different needs and applications. But in general (and this is true for any product, not just antennas and radios) there's costs involved in manufacture that lead to "you get what you pay for" roughly holding true, excepting true innovations in design, which come about occasionally.
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I sussed it out because of his various video reviews on XHDATA D-808 receiver. He claims the D-808 is the best SW receiver in 2019 too, and he still seems swear by it.
I bought a XHDATA D-808 myself, and I too was quite impressed & satisfied with its performance. I concluded that his reviews on the D-808 have been all very accurate and factual.
How is "best SW receiver in 2019" defined? Best in the category of circa $100 portables? It could well be (I have no experience). Best radio you can buy in 2019, even compared to ham rigs and SDRs? Not so sure. :D
Not knocking what works for you, of course, everyone has different needs and applications. But in general (and this is true for any product, not just antennas and radios) there's costs involved in manufacture that lead to "you get what you pay for" roughly holding true, excepting true innovations in design, which come about occasionally.
Please watch the video. :)
https://www.youtube.com/watch?v=tnDqt7sbVaw
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For me, I have not done any type of tests on the radio, but it hears what all other radios can hear.
And it is definitely more sensitive than any Tecsuns or Sangeans or Sony that I own.
And I have had it now for over a year, took it to everywhere, dropped a few times onto the floor, used it to pair with my Heathkit transmitter and had a few CW contacts, it still works. Recently I bought another one NEW, because when the battery is getting charged, I want to use the other one.
After having used one for over 15months, now I have 2x D-808s. That tells something surely :D
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I own one and while I wouldn't say it's the 'Best' antenna, it is worth the $45.00 I paid for it. If you are just using a telescoping antenna or short wire, you will be quite pleased by the performance. I have mine mounted outside stationary N/S. I tend to use it on my SDR receiver,but I typically use my 135 OCF dipole when more gain is needed. Especially pirate stations etc. Have fun!
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Yeah, I have some doubts on the claim that MLA-30 is the best active loop antenna.
But I don't know, as I have never used one by myself.
I am curious how it will perform.
I was comparing my long wire in the garden and the TECSUN active loop, and the LW is far better on SW.
On MW, the TECSUN is very good. It pulls the weak signals quite well.
I think if you are living in a high rise apartment or underground flat, then maybe the indoor TECSUN loop would be better than nothing?
For MLA-30, I will update how it performed on the bands with the real radios I have, trying to listen to some DX signals I have been struggling to hear with my other antennas.
But certainly it ain't bad for the price if they all perform in similar manner, if you think how much the other active loops cost.
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There is no such beast as an overall, official 'best' antenna (or radio or anything else for that matter) for all users, so any time I read a review or video headline with 'best' in it I ignore that part and just see what the substance might be. Each of us has our own 'best' radio, antenna, etc., for a given use, a given application, but no single product can be all things to all men at all times.
Any item, of low, high or any middling quality, can be 'best' for a specific user/given need. I like the idea of the MLA30 antenna and I know a lot of people really enjoy using them, which is as it should be especially at its price point. It's one hell of a value if you ask me, and I don't own one yet! :) So I'm not knocking it at all. But 'best' is not only illogical, it's impossible.
I'm sure this has been linked here on HFU before (I can't imagine it hasn't because I think he's a member) but Martin Ehrenfried G8JNJ has a faaaantastic radio electronics website, including this thorough and helpful page on his analyses of LOTS of active antenna designs and products:
https://www.g8jnj.net/activeantennas.htm (https://www.g8jnj.net/activeantennas.htm)
He discusses the MLA30 style antennas (about two thirds down the long page) along with numerous other types. It gets into electronics/RF component theory and more nuts and bolts/ohms and volts than you might be needing or knowing, but it is a fantastic (and I think very fairly presented) page. It's not a ranking or claiming-best-of kind of list, just his view on different active antennas. If you haven't seen it before it's well worth the studying. If you have seen it before then never mind! :) The entire site's great.
Mike
N0TLD
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On the discussion re "best" receivers etc -- on portables, these days, because the bands have emptied out, almost any of
the older classic portables will perform wonderfully: SONY ICF-SW55, SW-77, SW-07, SW100s and Panasonic RF-B65s.
The problem found with many of the IC chip wonders, including the 808, is that they have built in artifacts and that appear
on certain frequencies occupied by stations still on the air. Example with the 808 I have is Guinea -- on 9,650 when using
a 808, there is a het which is NOT another station but internally-generated. It will be interesting to see whether the Tecsun
PL-990 and others that are available now, but not in final firmware versions, correct problems like the one with SYNC that plagued
the PL-880.
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I hope they do improve some of the issues with the PL880 on the final version PL990. I like the '880 a lot, in fact I like most of Tecsun's offerings very much -- I think they represent some serious value at their price point/s -- but it would be very nice to have a portable that sounded as rich as the '880 sounds (to me anyway) but with much better SYNC and birdie/internal noise performance. The S9900 is intriguing as well, and I'm looking forward to if/when Eton will finally come out with the Elite Satellit, the E-1/XM lookalike (and hope it performsalike). :)
Fully agree about the older classic portables performing wonderfully on today's less crowded bands, absolutely. I'm a big fan of the classic Panasonic RF Command Series (the RF2200 and RF1150 in particular for MW DXing) and Sony's ICF-SW classics you mentioned (the '77 is a real favorite). Lately I'm going realllllly analog with the Zenith TransOceanic R7000-2 for SWL and enjoying every second of it. Not saying one is best, or classic is better, or anything along those lines... but just reiterating that they are still excellent performers on today's SW scene.
Mike
N0TLD
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FWIW, too many people base 'best' on whatever fits their wallet. Hams are real bad about that, as are CB'ers. The other end of the spectrum holds true too. Just because it costs 10x as much, don't expect 10x the performance. A friend of mine used to complain of similar devices, "for that much money, it should have come in a gold box, or at least with a kiss."
FWIW #2, I have an MLA-30 and find it to be a fine performing loop for the money in an average high noise suburban environment. Don't expect miracles, but it seems to work as well as my home-built remote tuned loop. In a low noise environment, the story may be very different.
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I would think that the BEST product means that it has good performance and reliability and user interface .... etc etc, but also price is good.
I don't think they mean the best as some MAGIC wands stuff.
For example, if we look at NRD-545, it scores all the top on all the aspects, but it used to cost about 2k? Even used ones go for almost 1k easy.
For most average users of radio, it is out of their budget. So, maybe NRD 545 works best (I am not sure if it does actually), but price sucks, hence it cannot be the best radio.
But the 808 works well, and the price is good, hence it is affordable to most radio users. Hence it is the best radio?
From G8JNJ site, MLA-30 looks poor product from the test results, figures and the graphs. But then how on earth a very popular youtuber in the hobby comes out with the reviews like that? = MLA-30 works very well, as good as the 10 times more expensive loop antennas, and in some aspects, it outperforms the well brook, w6lvp and lz and all the rest?
From his radio reviews and other antenna reviews, he is not telling porkies in his reviews, and anyone would know that.
Anyway, that is why it is an interesting product. MLA-30 has been around for a while, and now it is time that users must see it for themselves, not just from youtube videos or on the sites figures and graphs, but the actual ability it pulls the DX signals from the noise.
If you are listening to mostly very strong signals not far away from you, then all this loops, verticals and outside TF2Ds, I mean they are not necessary. The builtin whip antennas will hear them very well with no extra cost, effort or space. It is only when you are trying to listen to the faintest, weakest or rare DX, you need these extra efforts and expense and external space for the DX antennas. So, no other criteria is more important than that, can the external DX antenna you just installed hear the faintest DX signals that you were trying to hear in real life SWling? Can it dig out the rare DX signals that you were looking for from the mush noise? - this is what really matters in judging any external / high performing DX antennas, I suppose. Hence the graphs, and figures and theories ... yeah, maybe these factors are what reflects the performance of the antennas, but does it really and truly reflect the real performance? I am not sure. I will find it out soon.
On the issues of the old analogue radios from Sony and Panasonic, yes, I think most of them are excellent radios, but as they are very old, most of them would have been developing some kind of faults in the parts. When it goes problematic, it would be impossible for ordinary users to repair them. Or if they get repaired and restored by the professionals, then it wouldn't be cheap. And there will be some parts which are no longer available too. So it is not 100% problem free option to get the old PLL radios with discrete ICs.
If they are older vintage radios with just transistors, caps, resistors and tubes, then they can be restored and repaired by the users with just DMM and soldering iron, and the parts are still plenty and cheap in the market. For that reason, and also sheer excitement of bringing back the old dead radios to life, I am passionate on the vinatge radio restoration :))
So, yeah, a little ideas and opinions on the subject from different people and angles, are always interesting to ponder :D
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I would think that the BEST product means that it has good performance and reliability and user interface .... etc etc, but also price is good.
I don't think they mean the best as some MAGIC wands stuff.
For example, if we look at NRD-545, it scores all the top on all the aspects, but it used to cost about 2k? Even used ones go for almost 1k easy.
For most average users of radio, it is out of their budget. So, maybe NRD 545 works best (I am not sure if it does actually), but price sucks, hence it cannot be the best radio.
You're defining best as maximizing the performance to price ratio, not the performance, then. Not sure what you mean by "price sucks", other than it is/was expensive? That's because it costs more to produce a better performing product. An RTL dongle is cheap, but I am not sure anyone would call it the "best" radio :D
I had a 545 for many years, it was certainly an extremely good performing radio. Was it the best? Certainly not, some of the WJ products for example had even better performance. But they also cost more :)
But the 808 works well, and the price is good, hence it is affordable to most radio users. Hence it is the best radio?
It's got (for some users anyway) an acceptable performance to price ratio. If you're a casual SWL, especially in a high noise environment, it may be the "best" radio for you, as a better performing (sensitivity, selectivity, image rejection, etc) radio may not be justified as you'll likely not be able to maximize its potential. I cannot imagine any context however where it could simply be called the best radio, period.
From G8JNJ site, MLA-30 looks poor product from the test results, figures and the graphs. But then how on earth a very popular youtuber who is not a beginner or idiot in the hobby comes out with the reviews like that? = MLA-30 works very well, as good as the 10 times more expensive loop antennas, and in some aspects, it outperforms the well brook, w6lvp and lz and all the rest?
That's his opinion, based on use in his environment. G8JNJ OTOH performed some very rigorous testing and gave us quantitive results. The real test of course is to try each antenna on the air, comparing results from listening to a variety of stations. And again, it's gong to depend on your environment. For example, I live in a rural area on a relatively good sized lot with generally a low noise floor. Best for me is not going to be the same as best for you. Likewise the guys in the middle of nowhere in Finland laugh at my comparatively "high" noise floor and lack of space and can set up (and take advantage of!) Beverage antennas that are several thousand feet long.
I think the MLA-30 has generated a fair amount of "buzz" in the hobby, which accounts for its popularity. And if you're a casual SWL, especially one in a relatively high noise environment, it's probably going to give you an acceptable bang for the buck, if you cannot justify spending more for a Wellbrook/etc, or spent the time building your own active antenna (Crossed Parallel Loop with LZ1AQ amp for example), or of course better yet erecting a full sized passive antenna, which is most likely to truly be the "best" antenna, at least for some portion of the bands, but may be impractical or outright impossible due to lot size, restrictions, etc.
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Well said Chris!
You have to take most of these product reviews with a grain of salt, particularly if you aren’t familiar with the reviewer.
And we all tend to hear what we want to hear in these reviews and ignore the rest. The product reviews on eHam are a good example of that....or Amazon product reviews... A significant amount of those are just “noise” and deserve to be ignored...or from people with an axe to grind...
As Chris points out, too little attention is spent on the environment that the reviewer is in. If his local RF noise level is high, then a product that has a low SNR may be indistinguishable from one with a high SNR. Or if someone lives on top of a mountain with low horizons in all directions, then most any antenna is going to deliver a lot of stations.
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You're defining best as maximizing the performance to price ratio, not the performance, then. Not sure what you mean by "price sucks", other than it is/was expensive? That's because it costs more to produce a better performing product. An RTL dongle is cheap, but I am not sure anyone would call it the "best" radio :D
I had a 545 for many years, it was certainly an extremely good performing radio. Was it the best? Certainly not, some of the WJ products for example had even better performance. But they also cost more :)
I don't know about RTL dongles at all, as I have not used them :D, but if you think about NRD545 from this day, you cannot deny that it is a grossly over priced product. What it is - I have had a few NRD receivers myself in the past = the 515, 525 and some of the marine models). They were nothing special or different from other receivers such as Trio R600, R1000 or YAESU FRG7000 in reception ability and quality. And the construction of the NRD radios are externally they are excellent with heavy metal casings, but internally they are just made of plug in PC boards just like your personal desktop computers in the 1980s and 1990s. Surely these PCBs have been manufactured by automated system in the factories, and all of them depreciated the price to tens and hundreds folds. The personal computers prices plummeted rock bottom from about 20 years ago due to this situation, but the radio prices which used exactly same infrastructure haven;t. They had been priced still premium, and even now they are going for high prices in the used market. So, if you are aware of this situation, it is natural to feel that their prices sucks compared to other products which uses plug-in PCBoards.
Are they super reliable or easy to repair or service? I don't think that is the case either. So they are not wise buy in my book.
For MLA-30, and all other similar type of antennas, I think they are designed to work good in RFI prone environment, and it is the one of the strengths of the mag loops? Otherwise, it does not have clear advantage over the traditional long wire in the back garden which costs less than a ten box or even less.
Yes, I do live in pretty bad RFI suffering residential area, so the HF receptions for the weak signals always been problematic, so will see if the Active Mag. Loop antenna will make any difference :)) For 29 Euro including delivery and all the fittings and 10m long coaxial cables with the antenna, I thought it could be an interesting experiment.
But the term BEST in reviewing a commercial product, I think it is a relative concept comparing with other products available in the market, considering all the aspects even the price and performance. There is no such as things as THE BEST product as such if we logically analyse the concept and the product, I suppose :D
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You have to take most of these product reviews with a grain of salt, particularly if you aren’t familiar with the reviewer.
And we all tend to hear what we want to hear in these reviews and ignore the rest. The product reviews on eHam are a good example of that....or Amazon product reviews... A significant amount of those are just “noise” and deserve to be ignored...or from people with an axe to grind...
Quite true. There's two (diametrically opposed) biases with respect to product reviews. If a customer is unhappy with a product, they're more likely to go and leave a negative review (this is quite common on Amazon, I take it into account when looking at the ratio of good/bad reviews). Alternately, customers may want to justify their purchase, to themselves anyway, with a positive review.
As Chris points out, too little attention is spent on the environment that the reviewer is in. If his local RF noise level is high, then a product that has a low SNR may be indistinguishable from one with a high SNR. Or if someone lives on top of a mountain with low horizons in all directions, then most any antenna is going to deliver a lot of stations.
Let's go back and look at the review of the MLA_30 from https://www.g8jnj.net/activeantennas.htm
It's based off a TL592B video amp IC. This is a very low cost IC, I just checked and they're $1 each at Mouser in qty 100 pieces.
The datasheet is here: https://www.ti.com/lit/ds/symlink/tl592b.pdf?ts=1594483659234&ref_url=https%253A%252F%252Fwww.google.com%252F
Likely it was chosen because it's a) dirt cheap and b) has a 50 MHz bandwidth, so it covers HF nicely. But it's not a low noise amplifier, and as G8JNJ notes there's several design flaws in the circuit that result in low sensitivity as well as a high noise floor, he says 20 dB higher than other active antennas.
So yes, if you're using this in a high noise environment (apartment, condo, next door to the plasma TV factory, etc) you're probably not going to notice the issues, especially compared to a simple portable radio with a whip antenna. And there's the common belief that "more signal is better", so if it increases the S meter reading, it's got to be working. Rather than focusing on signal to noise ratio (which again may be indistinguishable in high noise environments).
The biasing tee has a 5 to 12 volt DC/DC converter with an attempt to filter the inherent RFI hash that the converter will produce, but at this point that's trying to re-arrange deck chairs on the Titanic. Again this is a cost savings measure (and perhaps perceived ease of use for the end user, they can just plug into a USB port for power) vs supplying a 12 volt linear supply, which is what you should be using to power an active antenna (and can obviously retrofit yourself).
Side Note: There's an old electronics term called Muntzing. I won't go into the history (but please, Google it, you will find it fascinating), but basically it is removing components / simplifying a design down to the absolute bare minimum that sorta works. OK, a little history... in the original case, it was making a TV back in the 50s that would work if you lived in NYC itself and could see the transmitting tower on top of the Empire State Building or wherever out your window, but that's about it. Not sensitive, not very selective or resistant to interference, etc. But it worked. Mostly. The same thing is of course being done today with many products (you could make the argument that most of the Made in China junk on Amazon qualifies. Although some of it doesn't even mostly work).
Now, going in a completely opposite direction... The "youloop" from AirSpy for their AirSpyHF+ Discovery SDR: https://swling.com/blog/2020/03/the-airspy-youloop-is-a-freaking-brilliant-passive-loop-antenna/
Construction plans here https://swling.com/blog/2020/04/diy-how-to-build-a-noise-cancelling-passive-loop-ncpl-antenna/
This is a passive loop antenna. No moving.... err... active... parts. It makes use of the fact that the Discovery is a very sensitive receiver, so you don't need to amplify the signals received by the loop antenna. Any amplifier adds some noise (or a lot of noise if you use the wrong amp IC), so this approach avoids that.
I've not built one myself as I have no interest in an indoor loop antenna. But I have used my Discovery with an outside passive loop antenna, and it works splendidly. Not as well as a full sized HF antenna of course, I do not expect it to. So I expect similar performance from a youloop, scaling for size, and of course worse noise levels if you use it inside the house where it is going to pick up all sorts of RFI from your computers and such. The XHDATA D-808 seems to sell for about $110, the Discovery is $169. So for about half again as much more money, you're going to end up with dramatically better performance, obviously with the compromise of needing to tether it to a computer and not use it as a portable.
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Anyway, the vendor has shipped MLA-30 to me, so it will be here soon. Hopefully it shouldn't take too long :D
But for passive antennas and active antennas, from my own experience in SWL/BCL, it is not always the case that one type antenna is better than the other. Same with Indoor and Outdoor antennas, it depends on the propagation path at the time. Some times I couldn't hear a station on my external long wire, but could hear it on my indoor whip or loop antenna and same with the passive and active antennas.
Sometimes, no antennas be it external or indoors, active or passive, none of them could hear the station, but by standing up with the portable radio with its whip extended to full, and walking around in the room could hear the station at the point in the space. So I feel that it is always good to have as many type of different RX antennas possible and trying out with them all for the DX signals that you are after, and select the best antenna for the reception at the time. That has been my approach to SWL/BCL and selecting antennas on HF. In my book, it doesn't matter what the antenna is made of, or what the glorious figures and graphs it has shown from the tests. If it cannot hear the DX station I am after, then it must be committed to flames. :D If it hears the stations, then they are the antennas to stay :D
Just as a matter of interest, Chris, could you hear the Radio Zambia from Lusaka on 5915 kHz on any of your antennas on everyday? How is the reception? Which of your antenna hears it with the best signal?
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I was asking about the Radio Zambia NBC 1 from Lusaka, because it seems one of the toughest signals to receive here on any antennas and radios. If your are in NA, and EU or Northern Asia = Japan Korea Russia China, and can receive this signal on 5915 kHz, then I would like to know what antenna was used and and which receiver. Because that would be an interesting criteria for having a go with the similar set up here.
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I don't know about RTL dongles at all, as I have not used them :D, but if you think about NRD545 from this day, you cannot deny that it is a grossly over priced product. What it is - I have had a few NRD receivers myself in the past = the 515, 525 and some of the marine models). They were nothing special or different from other receivers such as Trio R600, R1000 or YAESU FRG7000 in reception ability and quality. And the construction of the NRD radios are externally they are excellent with heavy metal casings, but internally they are just made of plug in PC boards just like your personal desktop computers in the 1980s and 1990s. Surely these PCBs have been manufactured by automated system in the factories, and all of them depreciated the price to tens and hundreds folds. The personal computers prices plummeted rock bottom from about 20 years ago due to this situation, but the radio prices which used exactly same infrastructure haven;t. They had been priced still premium, and even now they are going for high prices in the used market. So, if you are aware of this situation, it is natural to feel that their prices sucks compared to other products which uses plug-in PCBoards.
I'm not sure where this axe-grinding has its roots, but it seems unfounded to me. The 545 was a top of the line receiver in its day, and had a price tag to match. Because they were relatively rare, they are still expensive. Plug in cards were the professional way of doing things and keeping the footprint down. Most everything else from that era was a one-board-wonder, like my R8B.
+-RH
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I'm not sure where this axe-grinding has its roots, but it seems unfounded to me. The 545 was a top of the line receiver in its day, and had a price tag to match. Because they were relatively rare, they are still expensive. Plug in cards were the professional way of doing things and keeping the footprint down. Most everything else from that era was a one-board-wonder, like my R8B.
+-RH
No no, nothing to do with axe grinding. This is a radio forum, not tool forum :D
Yes, they are very good receivers, but from my experience of owning the NRD radios = 515, 525 and a Marine model, they really didn't offer me anything special in term of reception quality. When there were RFI and QRN in the house, they were very very noisy, and it was difficult to listen at nights. I let them go in the end, having lost interest on SWL/BCL hobby. But they were bloody expensive at the time.
The high price of them, I felt I couldn't justify. And I am not sure if they are still producing the NRD radios now. But for me, plug-in module type radios are like also for reducing the cost of them, because they can mass produce them in the factory in very quick time. All the electrical and computer devices in this type of construction have come down in price by tens and hundreds of folds but the performance hiked to tens and hundred folds too. But the NRD radios haven't. They are still keeping high price in the used market = this is maybe due to rarity factor? as you pointed out, rather than the performance or any other aspect?
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Plug-in cards were usually used for serviceability, and the ability to add more functions in a limited space. Look at any piece of professional broadcast gear, processors, routers, and the like all make use of plug in cards. Most of the film audio equipment I've run across in the past was build this way as well. Outside of WJ or Harris, this was an uncommon thing in the HF equipment world, as these were all commercial class receivers. I imagine this was one of the design criteria for the NRD stuff, although I've never had the chance to see one in the wild.
Just a guess....
+-RH
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Of course mate, not questioning the plugin module design advantage on the serviceability and performance and standardisation and all the rest of it. But the price of them went down too. If you were around buying computers in the 1990s, you will recall how much the miserable pentium and 486 386 PCs used to cost with the plug-in boards for the graphic and sound cards and modems etc. They used to cost 2k and 3k at the time for 1x PC with just 2-3 plug in modules into the motherboard.
But with the mass productivity, now what? They cost less than a fiver maybe? Or no one really want to even take them for free? And the plug in cards and boards were piling in the recycle places like mountains and mountains.
So, naturally the NRD radios price must have come down logically, but they haven't due to collectability and rarity? That was just passing guess, but just 2 cents of opinion. It doesn't matter, if one like it, and keep it and used them for SWL/BCL no matter how much they have paid for it? So be it. I like my D-808 and old Heathkit receivers for just fun, but these old radios and D-808 does what all other high grade radio do, as long as they are fed with the right antenna for the propagation path of the signal. :)
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Of course mate, not questioning the plugin module design advantage on the serviceability and performance and standardisation and all the rest of it. But the price of them went down too. If you were around buying computers in the 1990s, you will recall how much the miserable pentium and 486 386 PCs used to cost with the plug-in boards for the graphic and sound cards and modems etc. They used to cost 2k and 3k at the time for 1x PC with just 2-3 plug in modules into the motherboard.
But with the mass productivity, now what? They cost less than a fiver maybe? Or no one really want to even take them for free? And the plug in cards and boards were piling in the recycle places like mountains and mountains.
So, naturally the NRD radios price must have come down logically, but they haven't due to collectability and rarity? That was just passing guess, but just 2 cents of opinion. It doesn't matter, if one like it, and keep it and used them for SWL/BCL no matter how much they have paid for it? So be it. I like my D-808 and old Heathkit receivers for just fun, but these old radios and D-808 does what all other high grade radio do, as long as they are fed with the right antenna for the propagation path of the signal. :)
You cannot compare the cost to manufacture a computer vs a high end communications receiver. Your desktop PCs are being produced in annual quantities several orders of magnitude higher. With substantially different components. Apples and oranges.
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You cannot compare the cost to manufacture a computer vs a high end communications receiver. Your desktop PCs are being produced in annual quantities several orders of magnitude higher. With substantially different components. Apples and oranges.
Computer was just an example of the high priced electronic devices made of plugin module boards, but the main topic was the plugin board designed electronics devices in general, be it high end communication receivers or computers. And the high end communication receivers with the plugin module boards are strictly speaking in its construction, a type of computer with an operating system and ROM chips inside with just some RF boards added to it, which evolved into full blown SDR.
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Wow, that is quite a discussion. Here's my 3 cents. The NRD receivers were near the top of the heap -- especially 515 and the 545, though the last in the line (545) had to the ears of some still some audio harshness issues. I still have tow 545s and they are like riding in a Maserati. Similarly, the JRC marine radios NRD-93 and up are like a ride in a sports car (though the NRD-630, very rare -- went to DSP like the WJ 8711).
As for antennas, I have not used a MLA-30 -- I use a Wellbrook 1530 (the older LNP) and a W6LVP. I hope to test the W6 with a MLA amp box -- so far the W6LVP has been the most quiet, though at some points needs a boost from a RPA-1 or other amp box.
If the MLA-30+ gets anywhere near the W6LVP, that is quite an accomplishment for a cheap, mass-produced made-in-China loop.
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For example, if we look at NRD-545, it scores all the top on all the aspects, but it used to cost about 2k? Even used ones go for almost 1k easy.
If you can find a JRC NRD-545d for $1,000 please let me know .
Thanks
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Wow, that is quite a discussion. Here's my 3 cents. The NRD receivers were near the top of the heap -- especially 515 and the 545, though the last in the line (545) had to the ears of some still some audio harshness issues. I still have tow 545s and they are like riding in a Maserati. Similarly, the JRC marine radios NRD-93 and up are like a ride in a sports car (though the NRD-630, very rare -- went to DSP like the WJ 8711).
As for antennas, I have not used a MLA-30 -- I use a Wellbrook 1530 (the older LNP) and a W6LVP. I hope to test the W6 with a MLA amp box -- so far the W6LVP has been the most quiet, though at some points needs a boost from a RPA-1 or other amp box.
If the MLA-30+ gets anywhere near the W6LVP, that is quite an accomplishment for a cheap, mass-produced made-in-China loop.
I have had a 515, 525 and 93, and they looked real cool on the desk. But they were nothing special in reception capability. I mean they were very good, but if there was QRN, then it suffered. If there was no propagation for the signals I was trying to listen, they couldn't receive. They were just like any other communicate receivers. They had good audio and looked cool and made well with high quality parts.
But for NRD545, they are still very expensive here in EU, even the used ones. I am sure it is a good receiver. I have not had it before, but I read reviews that their audio is harsh, it is made of cheap plastic on the front facia, and mostly critically, they are no longer supported by the manufacturer? I mean all that glorious marketing slogan - superb serviceability with the plugin module design, but not supported by the manufacturer? Whats the point?
Not grinding axe or anything, but just my passing thought on it :D
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For example, if we look at NRD-545, it scores all the top on all the aspects, but it used to cost about 2k? Even used ones go for almost 1k easy.
If you can find a JRC NRD-545d for $1,000 please let me know .
Thanks
I think you might get one from eBay by BEST OFFER?
But I would personally rather go for a new ICOM receiver (forgot the model number but very pricy), if going for a new rig, which is fully backed by the manufacturer = it is important when buying a brand new radio, I reckon.
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Here's the test data for top end radio receivers. http://www.sherweng.com/table.html (http://www.sherweng.com/table.html)
NRD-545 rates right up there with a Kenwood TS-430.
As for the MLA-30, at least on MW, it doesn't outperform a Belar shielded loop sitting side by side in the same room. I wouldn't expect any active magloop to outperform an active shielded loop indoors.
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I was doing a bit of testing between my 135' OCF dipole and the MLA-30 on the roof. Although the OCF is better for weaker signals, I gotta say the MLA is quite a bit quieter on shortwave broadcast with a strong signals and it does show some directional gains. No regrets about my purchase. I may even buy a second just to use with me Grundig portable.
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I have seen quite many SWLs BCLs using MLA-30 with good results for DXing. Some of them have implemented their own DIY loop element either in shape of flat metal or copper pipe with thicker diameter, and seems improve the performance even more.
Also some of them use longer element size to work better on the lower freq. etc. I myself quite look forward to using it, and placed an order of another MLA-30 this time for the later "PLUS" version.
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I also tested at on the various time stations 5.000 , 10.00 and 15.000 and it received very well on the 5Mhz station. I expected it to perform better on the 15mhz station, but it worked better lower. I need to get a rotator set up.
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From my experience, it's difficult to get significant directionality with loops on HF, at least as far as the distant stations are concerned. Somewhat easier on MW.
However it's much easier to get good directionality on local RF signals, such as RFI. So a rotator can still be useful for trying to reduce local RFI levels.
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True
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So you don't need a rotator for SW.
For MW, yeah it will make dramatic difference.
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You could mount the loop on a cheap camera tripod, and rotate it by hand i suppose, if your receiving signals are directional. Or have 2x loops, install them for different direction, and use them by switching over. (This is what I will be doing.)
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Thats true. Especially if your using MLA-30's. you could have 2 loops in two directions for $100.00 or less.
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My 1st MLA-30 was 29 euros, the 2nd one PLUS version was 34 euros. Both total was 63 euros including FREE delivery.
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Alpard, I assume you received your MLA-30 (I could be wrong) If so, what do you think about it so far?
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No, they still haven't arrived yet.
They have shipped from China, and will take many days to arrive. :(
That was the only problem before I hesitated ordering one.
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Magloops can also be mounted horizontally, which points the null straight up and straight down, making it generally omnidirectional. In practice, a horizontal magloop should be mounted as is practical.
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Good point.
Here is MLA-30 comparison with other Loops by the youtuber.
https://www.youtube.com/watch?v=V7bp5OII0rs
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My MLA-30 plus arrived yesterday. I temporarily set it up in the room for testing, and it works very well.
I found that,
1. it is very directional. For receiving Radio Japan on 15Mhz, it completely nulled the signal out when positioned East West.
When turned to North South, the signal peaked and copied.
2. Supplied wire element is good for up to about 7 Mhz and above. Below that it degrades performance. Then when attached with long wire with alligator clip on the element for 6Mhz and below, the reception works better.
I think it is better than anything I have had - long wire and active whip. I think this is a great DX antenna, but will need to set up on a little tripod, and should be rotated.
It could be set up as horizontal for omni directional antenna, but most BC stations on HF seem transmitting on vertically polarised antenna. But one could do some testing on that to figure out which polarisation works better.
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...It could be set up as horizontal for omni directional antenna, but most BC stations on HF seem transmitting on vertically polarised antenna. But one could do some testing on that to figure out which polarisation works better.
FWIW every curtain antenna I've every seen at a shortwave broadcast station was horizontally polarized.
+-RH
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Then horizontally installing the rx antennas are OK? You don't need to get the rotator.
Rotator sounds a bit too much hassle due to the amount of cables wired into the control box, and also they tend to be expensive.
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As Chris noted, it is an inexpensive video amp IC with a bias tee power feed.
There is no particular reason it even has to be used for a loop as shipped. It could be used as a remote preamp for a variety of antennas, though I would suggest sticking with something balanced like a dipole, T2FD, loop-on-ground, or similar. It might suffice for a reduced-length beverage as well, though I suspect it might actually lower the actual resulting SNR of a quiet antenna given the amp design. YMMV.
I have a MLA-30 of whatever revision, though I have not done much with listening with it. It worked "okay" in a quick test with an indoor scrap wire loop near an exterior sliding-glass door.
Of note I removed the USB port and bypassed the regulator to feed DC without the voltage conversion. I have not done any testing at difference voltages, but a 9v battery seems to work okay. Lower voltage into the amp might even improve the noise, phase distortion, etc. Again, YMMV.
@alpard, if opting for a horizontal solution, either get it high as possible with a small loop like the one packaged with it to help limit ground losses, or alternatively consider trying it with a loop-on-ground of moderate size.
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Thanks for your info and advice.
My 2nd MLA-30 arrived this morning. It was in a small bubble plastic packet, and very light. I couldn't believe it was the MLA-30.
Upon opening the packet, I noticed it was MLA-30+ instead of MLA-30 I ordered.
So, I have 2x MLA-30+ now. I have been using the 1st MLA-30+ for about a week now, and it works great. It pulled many DX sig. I have never heard before, or struggled copying with my long wire such as CFRX Toronto 1KW on 6070 and Zambia NBC1 from Lusaka Zambia, and TWR from Botswana ... etc etc. It seems work better at nights.
There are times and signals that LW works better, so it is good to have both antennas.
Yes, I think it could be used as general RX ant. rather than just magnetic loop. It worked quite well when connected to a random length of wire too.
The 2nd MLA-30+ will be used with larger and thicker element to cover the lower freq. better.
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The discussion inspired me to continue modifying the MLA-30. I removed the attached coax and installed a connector at the preamp. Now I can use RG-6 or whatever.
Linked below are a couple of pics showing the MLA-30 as a preamp for a YouLoop simply hanging on a kitchen chair near a sliding glass door. Worked about as expected for an indoor antenna here.
https://imgur.com/a/fGCz3Yk
Now to get the MLA-30 outside sometime. Maybe over the weekend.
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Looks interesting. Let us know how it worked.
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I wrote earlier about my impressions of using the MLA-30. A few words for this informative discussion.
- the cheap balanced amplifier used, has high self-noise and the input is not optimized for loop resistance
- powering the amplifier through the DC5V / DC12V converter is convenient, but it causes additional interference
There are publications on the Internet on how to improve these conditions.
- Amplifier voltage changes in the range from 5 to 12V did not cause a noticeable change in the noise level in the receiver. Maybe this is due to the noise level in my environment?
I haven't tried bringing the MLA to the garden yet, but I hope to significantly reduce the level of interference compared to the interior of the apartment.
The MLA 30 has a clearly directional characteristic, which is its valuable advantage and allows you to draw an interesting station from the crowd received on another antenna. For this reason, more advantageous than horizontal is vertical antenna polarization. The signal received in horizontal polarization was smaller than from directed antenna in vertical polarization. Practice shows that the polarization of the incoming radio wave changes during reception due to reflections from inhomogeneous layers of the ionosphere. For this reason, we can only talk about the advantage of one of these polarities.
I rolled up a new loop of 5m long PEX / AL / PE 16 / 2mm sandwich pipe.
The new loop with a diameter of 160 cm improved MW reception and reception deteriorated around 15 MHz. It is difficult for me to say whether the antenna's efficiency has improved.
General conclusion, if you cannot put up an external antenna, set up a cheap MLA outside the window.
I was disappointed with the low signal level, hence another modification - loop tuning to resonance with an air capacitor (around 600pF).
The large loop is coupled through a small coupling loop with a diameter of 1/5 of the large loop.
A small loop is connected to the MLA amplifier. Now this is just happening, but not only good - noise has increased significantly. You need to work on the level of feedback between the loops and consequently the optimization of gain and noise level.
Such a large diameter of the loop is inconvenient to turn it, so in the next stage I rolled it into two coils, obtaining a diameter of about 81 cm. I haven't had time to test this setup yet, but the tuning range and signal level have not changed noticeably.
Tasks to be performed in the new year:
- install the MLA in the garden
- do remote antenna rotation
- do remote loop tuning
If I do, I will write about the effects.
P.S. The new MLA-30+ uses a different input amplifier and changed the power supply. .
Did this reduce self-noise?
Write what you know about it!
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I bought one of the MLA-30+ about a year ago. Compared to the 30' vertical in the backyard, the MLA-30+ is about 20dB noisier. Signals that are discernable on the vertical are buried in noise with the loop. The noise floor of the amplifier is just too high, and that is with a home made power injector, not the provided one. I love the loop concept, but the front end needs work, and there are many solutions out there that I'm sure perform better.
...But for the price, it's hard to beat.
+-RH
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I have put my MLA30 in the garden about 6ft above the ground, and it seems working a lot better (cleaner sounding and more signals heard).
I also have used different BIAS-Ts from the different active antennas such as Spectrum communication and MFJ. They don't use the stepper voltage system in the BIAS-T. They use straight 12V input and output system.
The result was that, I was not sure. The MLA30 sounded a bit more cleaner and quieter, but not that much. And DX signals? I don't think it made much difference.
So, I put the original MLA30 bias-t on. The noise floor of antennas seem a lot depend on the surroundings and band conditions rather than BIAS-T.
But as said above, if I was living in a flat with no gardens or outside land to put wire or vertical or dipoles, this MLA30 would be the only antenna I would use.
It is not the best DX antenna on the market for sure, but it works. And it can hear some DX too depending on the band conditions. And for the price and space it takes? It is a good value for money antenna that works. It will work better for LW if the element is replaced with slight longer one. But for MW and HF, it is good with the original element. I especially like its performance on MW. But on HF? I prefer my longwire and dipole. They hear far more weak DX signals when matched with proper good baluns.
MLA30 will work far better, if it were rotated to the signal direction.
But seriously fort the money? Not a bad antenna. It is easily worth five times the price. Not quite 10 times, but hey 5 times? A good deal for sure.