3 Minutes That Will Change Your Ham Radio Life. The MFJ 1788 Loop. See and HEAR The Difference!
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- Опубліковано 9 вер 2020
- Find me on Twitter at: LeosCoast2Coast
Three Minutes that could change your shack into being an amazing complete station!
A concrete comparison of the change in noise floor/S Units between the MFJ 1788 Receive/Transmit Loop Antenna at 22 feet high vs. a ZS6BKW dipole at 48 feet high and an AV 680 vertical antenna at 33 feet high.
It’s a great example of WHY your station should have a receive loop for receiving signals if you’re using a dipole or a vertical antenna to transmit on.
A dipole and vertical are great for transmitting but not for receiving.
A receive loop antenna is designed to receive signals you’d normally miss because they’re just too low in the noise on your other antennas.
The bonus to the MFJ 1788 is that like the MFJ 1786, you can also transmit up to 150 W on it!
So you can hear the very best you can plus transmit very effectively as well.
Give your shack the best it can to not only transmit but also receive.
Make sure and get a receive loop to make your QSO numbers rise, and your speaker sound much better than ever before.
It’s like buying an entirely new radio once you add a receive loop antenna.
MFJ carries three different receive loops, the MFJ 1886 receive only loop, the 1786 receive/transmit 10m-30m loop antenna and the MFJ 1788 receive/transmit loop for 15m-40m.
Both the MFJ 1786 and 1788 receive/transmit loops can operate from 1/4 watt all the way to 150 watts of power
MFJ can provide you everything from amplifiers to antenna tuner‘s from antennas to noise cancelers.
Find out more about all that MFJ can for you, to improve your shack at this link: mfjenterprises.com - Розваги
Yes the loop will reduce noise outside of its tuned frequency because of its narrow bandwidth. I agree this can be beneficial as it will reduce sperious transmission on TX and image rejection and IMD on RX. The real test however is how well does it receive a weak signal compared to the other antennas? As others have said, you could switch in a dummy load and get the same results. Please make a video comparing receiving a weak signal. That is what I need to determine if I want to lay down $550 to get one of these things.
73's
They are worthless for receiving. I recommend you budget in a second antenna for receiving
First of all : those who say : switch to a dummy load REALLY should learn about magloops and realize that they were used ( and still ) by military . Because of the LOW noise you CAN listen the weak signal . A signal you may can't because the noisefllow by a "normal" antennas . There are alot variables to consider but the basic should be learned .
Great information Larry. Great Technical stuff that I intend to try also. I really enjoy Ham Radio. I have always enjoyed the “mystery” of radio signals from when I was a young lad. What about your comments you made towards the the end??? Gotta tell you my friend.... I loved every bit of it! With all that’s going on today, there’s nothing quite so satisfactory at the end of a video or other type of communique as to the announcer wrapping things up with enthusiasm followed by the most important message of “God Bless You “!!! And here’s right back at you too Larry, God Bless You also!!! Wesley Kicker
Sweet, Chico.
Wow what a difference! I'm going have to consider this (or one of those three you mention) antenna. 73 KD2LMR..Dave
sorry, but if I switch to my dummyload, I also get S0 noise floor :-) ... to compare a dipole or vertical with the loop, you need to compare it with cw/ssb signals
Your Dummy load isn’t an antenna except for strong signals. This loop will hear weak signals. Big difference.
@@HamRadioLiveShow That point might have been better made by comparing weak signals in an a/b after showing the effect of switching on the noise floor with the waterfall. Your demonstration (as filmed) only showed that the MFJ antenna wasn’t as sensitive across the band as the dipole. There were signals on the waterfall that disappeared as well as the noise.
@@HamRadioLiveShow
I seriously disagree. I got better reception off a clip lead on the back end of my rig than this "transmitting loop" 45 foot up in the air.
@@HamRadioLiveShow antenna does not know noise from signal. Receiving antennas can improve signal to noise ratio only if they have good directivity. Efficiency for receiving antenna can be very low, and that is why they can be much smaller than transmitting antennas.
Very good comment! Antenna can improve signal to noise ratio only if it has good directivity.
I've got a Dummy Load in the back of my Radio, No Noise whatsoever.
A Dummy Load every time think about it.
Pros: Cheap to buy, No planning Permission, Internal in the Radio ect..
Cons: You can't hear bugger all...
This reminds me of a MFJ Magnetic Loop..
This is a perfect example what happens when radios are thought of as TVs
I live in a town in the UK and the noise floor across the lower bands can be anything up to S5. I bought a Wellbrook loop a few months ago and it has brought my noise floor down to S0. It's an active antenna and I do share the output between two radio's and whilst the signal strength is typically a little lower than a resonant dipole, the s/n ratio is much, much better.
It's a shame that fewer radio's seem to have the ability to use an RX-only antenna, especially given the increase in the electrical noise floor.
AMEN!!! This is one of the best comments I’ve ever received.
Coming from shortwave I used to use loops all the time. I know the value of them for a ham radio. The problem is, most hams reject this principle… That’s the honest truth. A loop antenna simply makes your receiver work better.
Top comment! Enjoy that Wellbrook!!
Larry
de K7HN
Hello a super positive short film. Sorry, I didn't understand exactly what you use for a plastic mast. Is the difference in relation to the QRM so noticeable? Another question about the 40m band, how good is the antenna on the 40m band? I have the other version from 30m to 10m. Thanks for the answer?
Horizontal anything always beats vertical for low noise.
Can you do the same test, but show a station to see how much the signal drops? If a station is S6, are they still S6 on the receive loop? Thanks!
Just trying to understand. I saw noise reduced but I also saw signal reduced. At the end of the day receiving is all about S/N ratio. Please explain if I am wrong.
I am getting a MFJ 933C shortly. I am using an indoor dipole now. But my big issue is the TX more than the RX. Will the loop TX better than the dipole ?
Great demo, but maybe do one with a steady signal underneath (like WWV) to show how it sounds before and after switching in the loop!
I love mag loops and think they are fantastically useful antennas but here you don't seem to be comparing apples with apples here. Your vfo seems to be tuned into a signal (as seen from the centre of your waterfall) so flicking between antennas seems to be showing a drop in signal not noise...as also indicated by all the other signals on the band falling off your waterfall too.
I do agree that the high Q of a mag loop can significantly help the crap front end filtering of something like an ft817 with its compromised design (especially on a full sized base antennas on a crowded 40m at the weekend) but I would be interested to hear the experience of other hams (with decent rigs like yours) trying to duplicate the miraculous effect you have had.
Hi Ian,
Thanks a lot for your post. I do appreciate it.
This video content was to show how much noise floor drops over a wire (dipole) or a vertical. both of those antennas are great for TX but not optimal RX (especially weak RX.)
When noise floor drops, weak signals appear out of the noise whether using a panadapter or tuning by ear.
My SW receivers, showed this to me for decades as well.
If you like loops, you already know all this. This short video was only to show how much of an impact in noise reduction drop a loop can provide.
A panadapter screen simply makes it a “visual example” as to an easier to “see” drop in noise floor over a dipole or vertical by using a video screen over only a speaker.
Some people learn things by “seeing”, some people by hearing. As a former teacher, I try to use other methods to show various things when I can.
in one example of this very short video, you can see weak signals come up that weren’t able to be found before because the noise was hiding them on the dipole antenna I use.
That’s the point. Use an antenna that’s made to RX on because it’s made to receive, then use your TX Santana to transmit on.
I’ll be doing another loop review this time for Chamaeleon, on their 2.0 loop which is a great QRP field loop and can be used at home too if you’re in an HOA that limits antennas.
I’ll spend a little more time on that review picking out some weak signals that would be lost in the noise floor if I was using a typical Multiband dipole. Not hard to find those kinds of signals on CW or SSB.
This video was meant to be “short and to the point.” Only three minutes. Just to show the significant drop in noise floor using a loop. That was it my friend.
Unfortunately, before doing the Chamaeleon review, I’ve ordered a noise canceller to knock out some terrible RFI that’s killing the receive on my 101.
I have a neighbor who’s a kind man, but has a HUGE RFI Flamethrower next door in a waterfall pump flow controller.
I’ve ordered the MFJ 1026 noise canceller to mitigate the noise so the test on the Chameleon will hopefully be more “apples to apples” to most peoples working conditions.
The Chameleon 2.0 is another well received loop in the hobby, (that can TX at 25 watts as well which is nice.)
In that test, because it’s a review Ian, it’ll give operators a better chance to see how a loop antenna can bring in signals otherwise lost in the noise floor , to make more QSO’s possible.
As you know, what you can’t hear above the noise floor, unless you’re working FT8 etc... you can’t work because The noise floor covers over the signal.
I appreciate you writing in Ian. Your kindness in taking the time to do so, was great.
Ian sorry no offence but your concept is junk . A magloop IS a compromised system so you can't compare to a full size antenna . To have a better result on a front end EVERYONE should learn the old way : a good mix between the RF Gain and the Volume . Turning at max the RF gain "because there's the agc" is because we want everything ready with one switch to press but this is also crap . Avoid the "tv screen" and stuff : what you really should use is called ears . The same thing that tell you if the readibility is enuf despite of the signal strenght . Magloops were used ( and still ) by military and we know usually they need the best stuff for some reasons . Is a magloop efficient of a well placed dipole ? NO, the magloop is LESS efficient . But the magloop makes you listening stuff wich may are impossible with a dipole due to the local qrm and stuff . You should uderstand the MAIN reason that makes someone to make/buy a magloop : the fight against the noise . I ONLY use magloops and i CAN listen while others who live on my same town simply can't : i can listen those S2 S3 signals on 40m...other hames have QRM at S8 . Decent rigs ? I had the ft 1000mp mark 5 and sold because it's a noisy radio . I use tube radios (Drake mainly) because they don't need more and more circuits to fight the internal noise due to the digital things . Again : i can listen signals that they are S2 or S3 ...others can't because they don't use a magloop . Oh and the "null" is very efficient to fight splatters and so on .
Thanks for doing this video. It would have been interesting to have seen how the receive compared. My vertical is noisier than my dipole but it hears signals that the dipole doesn’t. Your waterfall seemed to indicate the same. M7BCN
Good catch. It’s nice to meet you my friend. Thank you for taking the time to watch the show. I hope to meet you on a live stream soon.
Larry
Need to research how to run a receive loop on my station while running legal limit and don’t blow up the preamp on the antenna. Icom 7300, acom 2100, and a full 160m loop.
Hello, thank you for making the video and sharing it with all of us! I'm having some difficulty following along, is this receive only and we still transmit on our current antenna? Or is this a standalone antenna that can do transmit and receive? Thank you!
Ernest. Very good question. Thanks for your kindness. I truly mean it.
The antenna in this video, the MFJ 1788, will also transmit up to 150 W.
That’s the highest amount of
transmit power I’ve seen from a loop antenna.
It’s quite an amazing product!
To be able to get that much power out of a loop is fantastic.
I’ve worked from Northwest Oregon to Southeast Florida with it. Over land nearly all the way. Amazing.
It's worthless for receiving
This thread is quite long. Looking back, using an S2-S3 Receive signal would have driven the point home much better and that’s on me. I’m sorry it wasn’t clear enough.
The key: lower the noise floor.
Yo all of a sudden you start hearing signals that were buried in the noise
HOWEVER; the name of the game should be the best signal to noise ratio you can get. LOW noise floor... low signals will come in. Get that noise floor DOWN.
That’s the whole point. Use the RX loop to bring down your noise floor (as shown in the video), bring up your pre amps and the weak signals will suddenly appear. Just keep the loop at least 10m from your TX antenna and use an RF filter on it to protect the front end of your receiver on the RX input side if you’re running QRO especially.
I’ll be using a loop RX antenna with my K4HD on my UA-cam channel once the radio arrives. Stay tuned as they say lol.
OK I’m sorry do you video wasn’t effective enough for someone we all do our best.
Larry
de K7HN
Thanks Larry, I never realized how much the noise floor drops when using a loop antenna for RX. Thanks for the video, I found it very helpful.
Rick, thank you so much for your kind comment. I always found loops to be very helpful with DX before I became a ham. They always just seemed to work when other antennas didn’t. Thank you again for your kind words.
Newbie question: would you also use a loop for portable / rucksack type day out, as opposed to a portable vertical antenna? Cheers!
I’d use a wire dipole. Enough to carry already with the rig and battery. Keep things light. Just my thoughts my friend.
Larry
de K7HN
Did you aim the loop nulls towards the noise? I have the MFJ Receive loop, and my results are, err, less than what you're getting when I bump up the preamp to match signal strength. Maybe on 80 sometimes the loop is better, but mostly I'm still on the dipole for receive lately.
Maybe should be horizontal, not vertical?
If you have it mounteed horizontal, what maybe it's doing is, it has a deep null pointed towards all the electronic junk in your house?
Hello
I am planning to buy a loop antenna because almost in every band, i have awful qrm, for example s7 at 40m
S6-7 at 10m
It is better to buy an active antenna or a mag loop antenna?
Cheers de SV8SXB
As already mentioned, Signal to Noise ratio is the thing. Yes, I prefer a loop for receive, but you could be misleading new hams.
Hey Larry, Thanks much for the nice video but I think your conclusions may be all wrong. Whatever antenna you use just provides rf voltage to the input of the receiver. You proved that your vertical is really sensitive, your dipole is pretty good and the loop is well below in sensitivity. I'm just getting back into ham radio (licensed in 1958) and I have ordered a 1788 and now I'll order the type vertical you referenced as it seems very sensitive. I have HOA problems so that's why no dipole. Thanks again.
Ken,
The video was only three minutes long but it did prove its point.
When you use a loop Antenna, you’re “listening” on the magnetic side of the electromagnetic wave of a radio signal. No static crashes, less “electrical interference.”
Because of this, your signal to noise ratio is improved. You’ll need to use your pre amps to “bring the signals back up” but you will hear signals that are more difficult to hear because of QRN.
Noise goes down so signals can be heard.
I don’t recommend them for higher than the 20 m band, as atmospheric noise decreases significantly on 18m and higher.
The trick is, where you place the loop. Make sure it’s AT LEAST 12m away from any transmitting antenna as you can really compromise the front end of your transceiver and destroy it.
Remember, it’s a signal to noise antenna. Many top level hams and most high end shortwave DX’ers use loops for this reason. It helps to quiet down the band enough to hear weak signals.
Hope you have a very merry Christmas Ken!
Larry
@@HamRadioLiveShow Larry,
We grow too soon old and too late smart!! Thanks for the education. After all these years in radio and computers you'd think I would have known that.
Again, a fine video and again, thanks for your effort.
Ken
Can't really see what the video is proving ? Would it not have been better to pick out a signal and then compare the 3 antennas as opposed to a bit of band with nothing on but noise. I have the same radio and a great radio it is too but if I am comparing my various antennas I do so by selecting a signal (cw or voice) and then switch between each antenna to see which is best for signal strength / lower noise ? all you are doing is showing the spectrum graph changing. I could do exactly the same video and having nothing plugged into ant 3 I would get the same results
My friend, the whole point of that video shows you quickly how much NOISE your dipole or vertical picks up.
And how much that noise floor drops when you use a loop antenna for RX.
So you can HEAR the signals the noise is hiding on your vertical or dipole antenna!
That’s it.
You can hook up “nothing” and “receive nothing” or you can hook a loop up and receive signals that are lost in the noise because the noise floor is so high you can’t even hear them.
There is a better way to do this.
Use your dipole or vertical for TX. Use a loop for RX.
Because that’s what the loop was designed to do in the first place… Give you an edge on the RX side. .
Thanks for your reply.
@@HamRadioLiveShow It seemed though that switching to the loop also attenuated all of the other signals. Does the loop drop off so precipitously?
The loop shows lower noise and lower signal strengths .... Let's see how well it compares to am actual dipole on a real recieved audio signal .
The noise there needs to be addressed. Call the power company and tell them to get that corrected. If they push back, let them know your next call is the FCC. They will come fix it. : )
When are you going to buy one for me?
You would get the same result using a dummy load. Why no signal comparison ?
This test doesn't mean anything at all. Comparing a signal with its strength and noise attenuation with this antenna might be worthwhile but not this demonstration. 73 VA2RB
So is it no good tx your just using it for receiving??
I don’t think so. Worked from Oregon to SE Florida with it. I’ll take that.
I can get good noise reduction too - if I remove the antenna from my receiver .. How does the two antennas compare with a weak signal - that is borderline readable on the vertical ?
Judging from an earlier answer - it does work - but it would be nice to see.
Will this work on the 70 cm band as well ?
No, not on 70cm. As for the noise reduction. All I can say is I’ve done DX since 1973 and nothing out there can reduce noise like a loop. And you can transmit on this to which makes it quite a bonus.
@@HamRadioLiveShow But you didn't answer bodstrup's question. Does it reduce noise compared to a signal? I can do what you did in the video by disconnecting the antenna.
@@Species-rj9si it does....do some research on your own...check out loops on ARRL
I didn't come here to be told "do some research on your own."
You will have better reception with a clip lead than with this loop
Duh, reduce the bandwidth and the overall noise is lower. Sure looks like there are a bunch of signals disappearing along with the noise. Look at the SWR at either end of the spectrum display.
Reduce the bandwidth? Lol! That was over 100 KHz of bandwidth! How much more do you need?
Perhaps we work differently. I don’t rely on waterfall screens to find my signals. I rely on my ears to find them.
That’s getting to be more and more of a lost art today in ham radio unfortunately.
If you’re talking about the waterfall that was “lit up?” Keep in mind, that’s only the area where the SWR has been tuned safely at 3 to 1.
SWR as in transmit bandwidth.
SWR and “receive” have nothing to do with each other.
This antenna receives very well no matter where it is on the bands, from ham frequencies or MW and LW. That’s what well designed loops do.
You have a right to your opinion, but in this easy to follow visual example, the S meter and the waterfall don’t lie.
Environmental noise goes down significantly when you use a loop antenna over ANY dipole or vertical.
As for “the rest of the signals?”
They’re still there. I’ve already shown that in previous videos.
A loop lowers the noise floor from environmental noise and nulls RFI and strong signals in their centers.
There’s a reason that they’re used by the Department of Defense, our military and ham broadcasters when trying to triangulate broadcast signals. Because loops are designed to RECEIVE, they locate them.
While a wire antenna or vertical don’t because those antennas are made to transmit with, not receive with.
If you’re using a vertical or a dipole antenna you have probably a great transmit antenna but you’re missing out on having a great receive antenna. Add a loop and you’ll hear what you’ve been missing.
I wish you the very best on the air my friend. Good DX.
@@HamRadioLiveShow I'm just pointing out it's not getting something for nothing. A high Q loop is obviously a viable method of improving reception of a specific signal.
loctite222ms agreed. It’s an improved way to receive but not the only way. I use the channel to encourage interested hams to get their licenses, review products and show different ways to be successful.
On another note the smoke we have here from these wildfires are truly awful for anything to work. It’s been awful. Thanks again for your comment and for replying back. It was nice to hear back from you.
Is that antenna good for transmitting?
I don’t think this video proved anything at all, Larry. My first question is ‘was the loop antenna tuned to the same frequency as the radio?’. To further develop the thought experiment; I can give you even more noise reduction on receive by switching the loop antenna with a dummy load. I think the idea of a loop RX antenna with a preamp can be highly advantageous, that is not what you demonstrated in this video. 73 - Chris WB2DYJ
Chris, you dont “tune a loop” for RX. You do for TX but not RX.
You may be confused on this little video because it’s a RX/TX loop.
It shows a small window of SWR capable TX.
But if I use the MFJ 1886 or the Chamaeleon 2.0, I’ll lower the noise floor and find signals that the vertical and dipole won’t find. Every single time.
I’ve used loops Chris for RX for over 45 years. I’ll put one up against any non directional antenna you have and drop the noise floor more.
GUARANTEED.
ie: drop the noise floor, find signals you couldn’t find before because the weak ones were lost in the noise.
Even our ham radio licensing lessons taught us the value of a loop antenna for RX.
Thanks for checking in my friend, I hope we can work a QSO together soon. 73’s from K7HN
My fairly new MFJ Loop requires and always has required tuning for RX and TX. You can clearly hear the sound and signals jump in volume as you get to resonance using the tuning buttons. Then the loudest RX turns out to be very very close to the resonant TX setting EVERY TIME! The other thing is with a loop, you can clearly see the panadapter loses fidelity to help you find signals in a short span. Major drawback. I only use my loop as a backup. 73 de KI1Y
@@ChatGPT1111 The MFJ 1786 RX antenna has no tuning. Similar to the Welbrook loops.
ALL TX and RX Combo loops require tuning because they require transmit so SWR needs to be applied to the equation.
I would like to see the same test with a signal from some one talking to hear what that’s like.
That’s not the point of what a loop antenna does. A loop Antenna works Works signal to noise ratio. It lowers the noise, so signals are easier to hear.
To work this principle you need to use your preamp‘s on the bands you are listening on, because a loop only works off the magnetic part of the geomagnetic field and will cause receiver attenuation.
It works. It’s worked for me for over 49 years of DX’ing.
Another it's a 'magic antenna' infomercial.
Hey everyone, I turned on my preamplier and signals went by 6 to 9db and so did the noise...I hope I changed your ham radio life..
Yeah it’ll do that. But that’s not what this did. Noise went down signals came out. Pretty simple. Maybe too much so.
You don't show the effect of the same antenna changes on the strength of desired signals, including at various arrival elevation angles. Signal to noise ratio is the name of the game. My dummy load will show even better noise reduction performance, but it won't help me hear. While
(continued) While the antenna is probably a fine low noise receive choice, this demonstration doesn't show that.
Dear Bill,
I’m a pretty chill guy. I’ve been DXing SW, Ham and MW signals for over 47 years now.
I’ve used long wires, aluminum, coils and loops over those 47 years and learned the best receive antennas I could use on the best and most efficient receivers ever made were loops.
A loop antenna outperformed every other type of “receive antenna” There is.
But most hams are concerned with dbi, take off angle, radiation pattern and “will it fit on my property. Not one concern about RX.
My example clearly showed what I’d already learned from over 47 years of DX that a loop antenna will receive significantly better than a dipole or vertical antenna.
Your dummy load example is simple to replicate. “Simply find a S5 the S9 signal and you’ve got an antenna there in your dummy load your testing TX on.
My example clearly proved that the loop DID knock down environmental noise and drop the S Meter down significantly over a vertical or a dipole.
And it will do it every time. On every band.
It simply works. And more ham operators should be using one. They spend all their time and effort into getting the optimal transmit antenna while ignoring an optimal receive antenna.
This loop has not only heard many DX signals lost on my vertical and dipoles but also successfully transmitted a successful QSO more than 2,600 miles over land, not seawater.
Coast to coast.
And it was through such a dense smoke layer at my QTH when that QSO was made that it looked like I was transmitting from the surface of Mars. The sky was so orange, it was filled with carbon and smoke.
It just works Bill. You’ll hear signals lost in the noise much easier. I stand behind this 100%. Because nearly 50 years of experience was proven in the panadapter screen and S Meter.
Thanks for your comment.
@@KeepEvery1Guessing so, instead of belittling the OP, why don't you make a video of just that
@@lizzyfan1986 Sure. Buy me one of these antennas and a video camera and I'll make the additional measurements.
@@HamRadioLiveShow Bill is a troll
100% correct. Its like your cheating.. I have a RX Loop I use when I transmit on my EFHW, and the 1788.. Works great.
Every "receiving loop" should have a preamp, ferrite, or multiple turns. Otherwise what you get will barely make it down the transmission line.
It depends how high it is. If you’re using it 1 m off the ground or less, yes, preamp absolutely.
All due respect, this video doesn't tell me anything. A signal to noise comparison would give a very good representation of how the loop performs on receive. As others have previously stated, I can connect a 10' wire and it will show a significant drop in the noise floor but would be extremely ineffective in receiving signals.
Agreed. My MFJ loop was 45 foot up in free air, could be heard but I couldn't hear until I unplugged the loop and plugged a clip lead at the back of my rig.
I would never use this antenna. Small loop antenna has the same radiation pattern as short dipole with constant current. Basic lesson in antenna theory is often called "Radiation From Infinitesimal Sources".
You demonstrated that a loop is a crap antenna. I worked with this antenna several years and found it to be totally substandard. And you proved it. Did you see all those signals on the scope that disappeared when you switched to the loop?!? I found that if I could hear them I could work them with a loop, but that's just because only the strongest signals would get through. From my use I concluded that it actually pushed a signal fairly well, but the small capture area resulted in poor reception. Your video actually demonstrated that.
This does not show that the loop is quieter, or "better", or has noise reduction. It only means that signals, RF, electricity, is not making it to the receiver from the loop. The question that was not asked and not evaluated is - why - . Why is there less noise? Is it really noise on the vertical? I use a receive beverage antenna. Receive antennas are fine, and loops work. This demo looks good, but has overtones of a sales talk for loop antennas - maybe not science based. Then it may be an accurate experiement, with results that are accurate. Was the loop matched to the radio? Why did the loop also cause signals to be reduced (on the waterfall) - this implies that this loop installation is a poor receive antenna. Receive antennas must be matched to the receiver just as transmit antennas must be matched to the transmitter (swr). How do we tune, or pre-tune a system, using a tuner? Tune the tuner for max noise. Good info to think about.
Very well put and exactly what I would like to say.
So, loops are deaf?
No . They take away the QRM Noise . So all you hear is voices
Unplug the co-ax and you’ll go to S0
Looks like you lost many signals. At least on the scope.
For your demo to be useful, you need to demonstrate something much more meaningful which is the signal to noise ratio using a weak signal. Can you actually hold a conversation with a weak DX station on the loop that you cannot on the vertical or wire? Please show us again in a live QSO with an unreadable station. Then we all go build or buy a loop and throw out the ugly verticals and messy wires. (which of course will never happen as proven over the last 124 years.
All you have shown is how deaf the mfj1786 is! Do the test with a signal and get a real comparison.
Typical response I hear from many ham operators Who either have never used an RX loop or don’t know how to use one.
I’ll put a receive loop against any vertical or dipole and I will receive much better off of it than I will off of that wire or stick.
There’s a reason why high end SWL Dx’ers use loops for receive.
They simply work better.
Ham radio operators believe they know better…
But they have little experience at actually thinking about a receive antenna.
In fact, I bet never in your life have you thought about a receive antenna. You’ve only thought about TX. Most hams do. Everyone thinks about takeoff angle and DB gain.
It’s already well proven that loops are superior to RX on than a dipole or vertical but unfortunately many hams refuse to even try it. That’s unfortunate.
@@HamRadioLiveShow You may be right, but give a demonstration that will show it. This video shows nothing at all. You would probably have such a result with an indoor antenna. VA2RB
@@spintrap I appreciate you writing back. I’m sorry you didn’t understand the method in which I showed this. This video clearly showed signals coming up because the noise floor dropped down. That’s the beauty of using a loop antenna. I’m sorry that the three minutes supplied for this quick video wasn’t effective for you.
@@HamRadioLiveShow I'll look at it again. Seems i'm not the only one who haven't understood your video. Thanks !
@@HamRadioLiveShow I just look your video again. I don't change my comment. The fact that an antenna can reduce the noise level is no testament to its performance. Show us a signal with your vertical antenna then with your "loop" and then I will be able to say that it is a good antenna. If your "loop" receives a signal from S3 but the vertical receives S9, having less noise will not help me much to make contact. All this to say that your demonstration does not provide proof of effectiveness. By the way, your ham station is beautiful. 73 ! VA2RB.
I guess my confusion stems from calling the dipole a vertical and the loop a dipole then the dipole becomes a loop and the loop becomes a dipole, 3 minutes of my life lost...
The antennas were called out correctly. This was a three minute video. It was designed to be and it finished at the exact second.
Perhaps take a few moments to contact whichever ham radio company you have and ask them about that “RX Antenna“ input on the back of your rig and ask them “what kind of antenna you’d put there?”
I would be stunned if they didn’t say the word “loop Antenna.“
Because people who truly do know radio know that you hear better on a loop then you do a dipole or a vertical. This is so sad to me that there are this many hams out there that don’t really understand about loop antennas. I had no idea so many didn’t really know the value of a loop.
One thing I can say, if they have tried one they would not be saying the things that are said here.
With all due respect this is a very flawed demonstration, if you look at your initial waterfall there is what looks like a ham data-mode transmission near the left hand side of the screen which disappears when the loop is connected but is present both on the ZS6BKW and the vertical.
I used to work for a military electronics company, our own "magnetic loops" intended for tactical use were made from expensive materials but we still quoted them as having a "gain" of -13dB relative to a dipole. Conveniently about 2 s-points, not far from your drop in noise.
Contrary to a reply to another comment a loop of this type should be tuned for optimal receive power transfer. The tuning is not just beneficial for transmit SWR. Your plot does show some relatively low level QRM from perhaps a switchmode appearing as spurs across the waterfall. These would also vanish if you simply used an attenuator inline but again you would lose some copiable signals too. Undoubtedly some receive antennas can produce better signal to noise under some conditions relative to the main antenna. I too have been playing with both a ZS6BKW and a receive loop as well as diversity receive.
I know the video has been up for a while but only just discovered your channel, sorry if this comment seems harsh but we can easily fool ourselves that something works better than it does. 73
I understand your concerns. However, the main point was discussing the drop in noise floor with a mag loop. That was all.
I sincerely appreciate you watching the show and I thank you as well for your comment. I am OK with criticism as long as it’s delivered in a way that useful. Thank you for bringing the shortcomings you found in the video to my attention.
Larry
@@HamRadioLiveShow thank you for the polite reply, enjoy your radio and making videos.
Please use a tripod!
Dude...that's NOT how this works.
That’s how mine worked.
Noise floor LOWERS.
Signals APPEAR
Those signals were swallowed up by the noise before. Even the video shows those signals coming up.
The only advantage to using this loop is you can transmit with it as well.
Mag loops all work the same way (although many don’t need a tuner because they don’t transmit) any large receiving loop does the same thing. Because it works on the magnetic field, not the EM field.
Thanks for writing in but I’m sorry to tell you you this shows exactly how this works. The eyes and ears don’t lie.