SDRplay comparison of LZ1AQ and Wellbrook loop antennas
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- Опубликовано: 14 июл 2021
- In this video Mike Harwood compares the LZ1AQ active mag loop antenna with the Wellbrook 1530AN at a couple of frequencies using an SDRplay RSPduo which allows simultaneous visualisation of the 2 loops in action with real signals.
The Wellbrook loop is no longer available but was until recently a very popular choice of active magnetic loop antenna.
This is one of many videos from SDRplay - makers of the RSP family of SDR radios. See the full list of SDRplay videos and applications documents on: www.sdrplay.com/apps-catalogue/
The RSP family of SDRs from SDRplay cover 1kHz to 2 GHz with no gaps and give up to 10MHz spectrum visibility.
SDRplay is a UK company. The RSP SDR receivers are made in the UK and can be purchased for worldwide delivery directly from www.sdrplay.com/ (click on purchase and select your country to view shipping costs) or you can buy from any of our worldwide resellers listed here: www.sdrplay.com/distributors/ Many of the resellers offer local free shipping and/or local language technical support.
The SDRplay RUclips Channel is: / sdrplayrsp 
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I use the LZ1AQ in a very noisy environment since 6 years under the roof in a multi family home and I have a better reception than in the old days (80's and 90's) with huge wire antennas, only my beam would obviously outperform it on ham bands, but since I do a lot of utility DX and decoding over several bands, a narrow band antenna is not an option anymore. I am fascinated by this antenna and the totally symmetric ethernet concept. The antenna costs around a quarter or less of the Wellbrook but offers several amps that can be operated with two loops in a 90° angle and you can switch from A to B to A+B and one of those configurations will always give you a very good s/n ratio and the wellbrook would heva to be installed on a mechanically rotating system to do that and so you may have a better chance to precisely null out signals, but it comes to a price more then 10 times the LZ1AQ when you include a mechanical rotor. The control line of the rotor may also propagate RF noise towards the antenna unless you install chokes, so overall the LZ1AQ is hands down the winner if you want the best possible signals for the least amount of money.
Its immunity to intermodulation is also something I have never seen ... it sometimes brings my 16 SDR near its limit.
I have had signals with 90dB s/n! I receive FT8 signals from all over the world almost 24/7 ... like right now here at 12:42 local in Munich Germany VK8DR and VK6AL from northern and western Australia on 10m band! Yesterday I have received Hawaii, Alaska and New Zealand ... Radio Newzealand Intl almost like a local station ... with an LZ1AQ under the roof inside the house!
I recieve HFDL aircrafts all over the world ... this antenna is for a little over 100€ simply amazing. I use regular copper wire for my loops, cost me 10€ and I nailed the two loops on a wooden stick, on top of another 90° shifted ... so I can even use these in the electric capacitive mode, which works well in the lowest VLF range, but anywhere higher the electric mode is just picking up the enormous local noise, so make sure to operate the magnetic modes.
What I would like to see is that LZ1AQ feeds both antennas signals into the 100 Ohm ethernet cable and gives you two antennas outputs, meaning if you have e.g. an RSP Duo and enable the diversity phase shifter, you would end up with a physically stationary cross loop antenna that you can electrically rotate and you would the exact same effect as if you would have one loop that you can turn physically, which is always an issue with maintenance and it may make noise if installed in the attic ... when this can all be done by smart software.
Maybe this version already exists, and I simply have not visited his website for years.
Anyway I can only recommend the LZ1AQ for anyone who loves to receive shortwave with clear signals and doesn't want to spend a fortune and still get better results.
Thanks for doing these comparisons for us. It was obviously a real expense in time and capital which most hams would never attempt. I love my SDR Play Duo. Constantly being improved. Keep handing them out to HamTubers. That's where I first heard of your product demonstrated by Dave Cassler and Josh at HRCC.
Nicely done. Looks like a very accurate same-same comparison. THANKS. TT
I saw a slightly higher noise floor on the LZ1AQ, but not enough to make much audible difference. Looks like a very interesting product.
Great comparison
Sorry to see Wellbrook are closing down according to their site message.
a wonderful video, thanks
Thanks to Mark Harwood!
Looked like a very fair test. I never expected those two to be so close, given the wide range in their prices. Thank you!
No mention is made of the fact that the LZ1AQ loop comes as a kit that a lot of people would shy away from constructing. The Well brook is a "plug and play" product
@@g5vu It's not a kit in the manner you imply: the circuitry is supplied mounted and tested. You only put it in a box, make some (wire) connections and provide a loop. If that's not worth the ~£150 saving over a Wellbrook, I don't know what is!
@@MrMesospheric I think that we will have to agree to disagree.
Having used the LZ loop for a few years and in many positions and configurations, it needs mentioning that the CAT cable it uses to link the head and power supply needs consideration as well. I've used pre made flat Cat 5/6/7 leads, home made screened and unscreened. I've had quite different noise performance results depending on which I've used, no real conclusions.
I made an identical comparison between these antennae about 2 years ago and saw about the same results. Sadly the 2 waterfall windows were not identical setup and the RF gain level and the dynamic range was also different between the 2 receivers which does not give an honest visual result. These are the details to preset before running the test for an honest result. Sadly the VLF band is not tested and there I can say that below 30 kHz the Wellbrook is noticeably better. I cannot see what both antennae are using as power supply, but it should be a battery, as some power supplies can be noisy even if they are of the linear old school model. It's not easy to make such a test, but one does learn over the years from mistakes, and believe me I also made a bunch. Good informative video tough, but sadly not revealing all the details.
thanks for the feedback Ron.
No mention is made of the fact that the LZ1AQ loop comes as a kit that a lot of people would shy away from constructing. The Well brook is a "plug and play" product
That's a very good point, and I should have mentioned it. The LZ1AQ has more features, but you do need some electronics and construction experience to put it together - especially if you want to enjoy all of the modes. I'll make a note to expand on this in future videos.
@@Mike-H_UK The LZ1AQ kit was mentioned in the earlier video, I have a Wellbrook, I bought it because I was tired of waiting for over 4 months for MFJ to ship goods to my dealer in Canada. Although very expensive and I was not impressed with the bias-Tee being constructed on perfboard, I expected a good quality PCB for an antenna that was just about $500CDN including shipping from the UK. No issues with performance though.
@@JohnHill-qo3hb That's a good point, and if you look at the reverse-engineering work by George Smart (M1GEO) it appears that the main circuit was on a stripboard as well. I don't know if that is still the case or whether, over time, Wellbrook have moved over to a custom PCB. To be honest, I don't understand why Wellbrook would have used this construction technique for anything other than prototyping even though good performance can certainly be achieved with a competent strip board design. I'm sure that a PCB would ease manufacturing considerably, and a simple board like this could be laid out with free s/w.
@@Mike-H_UK I wonder if these are made to order. Yes, a high quality PCB with conformall coating would give a very positive feeling about build quality. Wellbrook has many commercial/Government customers, I doubt that there would be many people at these places curious enough to remove the four screws to "have a look-see" inside. It all comes down to performance, it works, it works very well, why change as it won't make any difference to the level of performance.
Looks like the LZ1AQ has the slight advantage over the Wellbrook which is interesting considering the Wellbrook is much more expensive to buy. It would be interesting to test the LZ1AQ head to head with the W6LVP loop.
No mention is made of the fact that the LZ1AQ loop comes as a kit that a lot of people would shy away from constructing. The Well brook is a "plug and play" product
@@g5vu it's not a kit in the usual sense. The boards are completely populated, no soldering required. Just build the loop, put some wires into some screw terminals, put the board into the box, etc.
Always been happy with my wellbrook but the LZ1AQ looks good but I wonder how much this is ? Btw I have never got a trace of 243 khz here :(
Just to say I now realize DR is only on air a few times a day. When on air I get s9+4db
95 EUR for all the electronics, you supply the antenna elements (copper tube or whatever).
Hula Hoops would be good for attaching wire to make cheap antennas.
*How many hours until* some are available on Amazon with free shipping from China?
The MLA30 already is!! That makes it very difficult to differentiate between good loops and the cheap copies....I've seen someone on RUclips make a loop by threading wire inside a hula hoop. It's probably best to avoid the more lurid colours!!
Thanks for this video. I just received my LZ1AQ box and was wondering if you think the size of the antenna conductor makes much difference? i.e., 3/8inch copper tubing versus 14 gauge solid wire?
Tnx es 73 de Arnie W8DU
Yes, it makes a difference. It's a low-impedance (current feed) amplifier so the sensitivity depends directly on the loop inductance. LZ1AQ recommends "as fat as possible", with 8ga wire as a minimum, but copper tube is definitely nicer. If you want to use wire on a frame, then I would suggest multiple conductors in parallel (*not* multiple turns in series!) to get the best result.
But of course you can build it with 14ga and see how it works; if it's good enough, it's good enough, and if it's not, then you just wire in something better. The rest of the system can stay the same.
@@hobbified RG213 coax outer is also very successful, as it is for portable tuned magnetic loop antennas for HF.
why do transmitting magnetic loops requires a tuning capacitors and not the active receive loops ?
When receiving you are dealing with tiny electrical signals resulting from the loop cutting through the magnetic field of signals- with clever amplifier design you can present these signals from a wide range of frequencies) to the receiver with good signal to noise ratios. When you want to transmit, you need to excite the antenna using large electrical signals and there needs to be good impedance matching to ensure power transfer and no damage to the transmitter. An air spaced variable C can provide the tuning and survive the high RF voltages involved.
What is really needed is an active antenna, like the one shown here under development, that will work off the +5Vdc Bias Tee built into the SDRPLAY receiver. Please ask this gentleman to make the active amplifier available or a schematic so we can build one at home. If anyone knows of such an animal designed to optimally work with the built in Bias T please let us know. Perhaps SDRPLAY could sell it online.
You could always buy a Wellgood; bias-T as standard. No need to activate from SDRPlay.
Well worth checking out the Minikits available as kitset or fully built 1M Loop amp based on the LZ1AQ here: www.minikits.com.au/eme234
Keep in mind Wellbrook is gone, so if you want one of their loops, you're likely out of luck unless something pops up on the used market
Hmm. In the 22m band test, the LZ is often significantly better than the Wellbrook. Something like a day of WSPR reception would provide objective, human bias-free data.
Rip off wellbrook!
To be fair to LZ1AQ, I think the circuitry looks very different, even though the SNR performance of LZ1AQ appears at least as good as the Wellbrook. If George Smart's (M1GEO) reverse-engineering of his Wellbrook loop is correct, then the Wellbrook uses an augmented version of the Norton lossless-transformer amplifier that Chris Trask invented and patented (now expired). I don't see the same fundamental technique on the LZ1AQ circuit board. Certainly LZ1AQ has many more modes and features.
No mention is made of the fact that the LZ1AQ loop comes as a kit that a lot of people would shy away from constructing. The Well brook is a "plug and play" product
@@g5vu That's a very good point, and I should have mentioned it. The LZ1AQ has more features, but you do need some electronics and construction experience to put it together - especially if you want to enjoy all of the modes. I'll make a note to expand on this in future videos.
@@Mike-H_UK Except, you don't. It's not an electronics kit, merely a very simple mechanical put-together job.
@@g5vu Funny, you've mentioned it at least three times now - always wrongly implying it's an electronics kit. It isn't. You just put it in a box and connect a loop.