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eHam Forums => Antenna Restrictions => Topic started by: KK4GMU on September 06, 2022, 07:34:44 AM

Title: Magnetic loop TX antennas
Post by: KK4GMU on September 06, 2022, 07:34:44 AM
How far should a magnetic loop transmit antenna be kept from a metal chain link fence or from metal patio furniture?

I have a very constrained small patio area only 8' by 20' surrounded by chain link on two sides and concrete block walls on 2 sides.

I am looking at the Pracomm SML-1000-1.
Title: Re: Magnetic loop TX antennas
Post by: K5LXP on September 06, 2022, 07:58:39 AM
Doesn't sound like you have much choice.   "As far away as possible", after that you get what you get.  Any chance of elevating the loop above the fence?

Mark K5LXP
Albuquerque, NM
Title: Re: Magnetic loop TX antennas
Post by: AC7CW on September 06, 2022, 08:03:10 AM
I had one in horizontal orientation up about 20' on a metal pole the base of which was about 8' from a chain link fence. I liked it for working cw on 30 meters because not much frequency changing was necessary. It seemed to be somewhat nvis... sunspots were low and i don't recall hearing any dx but I worked hams in the southwest region from southern california
Title: Re: Magnetic loop TX antennas
Post by: K6SDW on September 06, 2022, 08:10:18 AM
To quote KE0OG, the ARRL and QST new technical editor: When it comes to antennas "Everything affects everything." Dave has an excellent YouTube channel choc full of videos on simple to very complex technical subjects.

GL/73
Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on September 08, 2022, 06:08:34 AM
Here are some generalizations I've learned about magnetic loop antennas for transmitting so far.

1. They are best suited for portable use or for stealth/semi-stealth HOA situations. Deciding your primary purpose is key to the features you will need most.
2. They're not cheap:  Commercial ones range from $200 to thousands. The most popular ham versions are in the $300 to $400 range.  Home brew can be less than $100 with the limitations listed below.
3. The "big three" seem to be Alpha, Chameleon, and Alex. These are mostly in the +$300 to $400 price range.
4. They do NOT need to be mounted high up.  They can be mounted one loop height (36" to 48") above the ground.  They do not require a ground plane.
5.  Those less than $400 have limitations that many of the more expensive ones overcome, such as:

Since my use for such antenna would be stationary at home, I have no need for light weight, compactness, portability, foldability or carry bags.

I do have a need for the following:
In my opening post I mentioned the Pracomm SML-1000-1.  After two emails to them last week, and a phone call that went nowhere, I doubt they exist anymore, despite being reviewed by Dave Kasler a few years back.  But reconsidering that particular mag loop, while it can handle 100 watts, there was no remote tuning capability.

That brings me to MFJ.  Higher power handling (150 watts) and remote control.  Their MFJ-1788 gets mediocre to fair reviews, like 3.5 stars.  That non-stellar review is NOT due to the performance of the antenna once properly assembled.  I interpret all the reviews I have seen of that antenna as being at least a 4 or 4.5 star performer.  The great majority of negative reviews are due to MFJs crappy quality control.  Many reviews comment on bent variable capacitor fins, misaligned capacitor fins or loose shaft, loose or improperly installed screws and wires, and related fairly easily user-fixable items.  The performance of the antenna, once the "semi-kit" is properly put together, is generally praised.  But $700+.  Hmmm.  That is roughly $300 more than the "big three" mag loops.  For the extra $$$ you get higher power, remote control, and a semi-kit.

So, I have laid out my thinking to hopefully help those who are similarly HOA, space, and no-tree constrained, and who want an HF antenna that by most reports I have seen performs "almost/just about" as well as a multiband dipole up high.

If I got this, I would have to sell my MFJ-993B auto tuner and G5RV Junior antenna to help pay for it.

One of my favorite Florida expressions:  Is the juice worth the squeeze?

Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on September 08, 2022, 07:49:04 AM
I saw this on ebay for $300.  But local pickup only in California.  If it was in Florida I'd probably go for it.

MFJ-1786 Super Hi-Q Loop Antenna ~Now with REMOTE! LOCAL PICK UP ONLY 92647
Title: Re: Magnetic loop TX antennas
Post by: K5LXP on September 09, 2022, 10:39:21 AM
"Everything Works" - N6BT

Expectation is a significant factor of your project here.  You've put a few unnecessary (in my opinion) constraints on the situation and in reading your message, there is only one possible conclusion.  That being the case, full steam ahead - get the loop, put it up and you'll decide if it works well enough for your goals.  Seems it might be on par with a mobile antenna, and in that respect it will absolutely make contacts and maybe well enough to keep your interest.  My observation though is that is the best it will ever be, where with other options performance and capability would be better, which allows for operating under more compromised conditions.  Everyone has their minimum point on the enjoyment chart in N6BT's article but when you start at the bottom, that's as good as it gets.  I wouldn't be "all in" financially for a solution that at best isn't all that great.  If mag loops at ground level were "almost as good" as dipoles you'd see more people using them.

Mark B.
Albuquerque, NM
Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on September 09, 2022, 11:06:14 AM
"Everything Works" - N6BT

You've put a few unnecessary (in my opinion) constraints on the situation and in reading your message, there is only one possible conclusion. 

That being the case, full steam ahead - get the loop, put it up and you'll decide if it works well enough for your goals. ...  I wouldn't be "all in" financially for a solution that at best isn't all that great.  If mag loops at ground level were "almost as good" as dipoles you'd see more people using them.

Mark B.
Albuquerque, NM

What do you believe the "unnecessary constraints" are?

Living with and understanding my constraints, I am not yet aware of other options for HF except the G5RV Jr I have mounted flush on my asphalt shingle roof. Not fully tested, but it looks like low SWR on only small segments of couple of lower bands.

I suspect more people would be using mag loops if more people were living with my constraints. (Please refer to first post under  "Antenna Restrictions.")
Title: Re: Magnetic loop TX antennas
Post by: K5LXP on September 09, 2022, 01:06:09 PM
I used to live in the worst HOA ever - military housing.  After that I lived in a house on the national register, no visible antennas.  Then I lived in an apartment building with no yard and only a small community patio space.  I operated HF at all of them, and not one mag loop.  Fast forward to today and operating "portable" often results in people buying small loops and highly loaded antenna contraptions which might offer a "match" but especially QRP are frustrating at best to make contacts with.  You spend more time futzing around setting up and adjusting these antennas than making contacts in the field.  So from my perspective of over 40 years in this hobby operating HF in all manner of locations, you don't start with the poorest performing antennas, you go with the best performing ones you can possibly have.  Nearly always this will be a wire antenna.  Spending a bit of time figuring out how to orient some form of wire antenna within the space constraints will reap performance results over any "compact" reactance on a stick.  This isn't about breaking pileups or DXCC in a weekend running QRP.  Without an efficient antenna you run out of stations to work quickly, being more and more dependent on good propagation and strong stations that make up for your lack of signal margin.  Possible, and can be fun when it happens but you're locking in reduced opportunity with compromised antennas.  Sometimes you have no other choice but I wouldn't introduce limitations that don't actually exist.

Fairly stealthy (mounted low, not conspicuous)

What does that actually mean?  So a 3' loop on a stand is OK, but something like a nearly invisible wire or vertical isn't?

Compact (no long stretched out wires).

Would inconspicuous be OK? 

I have a small space, no trees on my property)

But there's a house, right?  Houses have height, length and depth, same dimensions as antennas.

Remote tuning.

Is in-shack tuning ruled out?

My priority is not an antenna building hobby.

This is a tight constraint.  You have a very specific set of operating conditions which demands a custom built solution.   You are binding yourself to find the lowest common denominator solution, eliminating even simpler, less expensive and better performing ones.  Yes, you or someone else might have to build and install it (somehow you managed to get a G5RV jr on the roof...).  You just have to weigh the option of an expensive poor performer that's plug and play, or stretch a bit and end up with something that will offer a better operating experience (read the N6BT article).

Mark K5LXP
Albuquerque, NM
Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on September 09, 2022, 02:43:53 PM
I find it amusing how some commentators can make assumptions about the physical and technical abilities of some of us asking questions about specific topics based on their own age, physical and technical experience and abilities.  Such advise would be helpful if I possessed their physical characteristics or knowledge.  Yes, if I had 40 years in the hobby I might have a solution.  But maybe not, considering the constrained physical environment in which I am located.
Title: Re: Magnetic loop TX antennas
Post by: WA3SKN on September 10, 2022, 05:21:54 AM
The mag loop is a poorly radiating "speciality" antenna with a VERY HIGH "Q" (narrow bandwidth).
You seem set on trying one though, so go ahead and try it.  Some apartment dwellers love them!  I would not get rid of the tuner though... it is a useful device to have on hand.

-Mike.
Title: Re: Magnetic loop TX antennas
Post by: AI5BC on September 10, 2022, 08:02:28 AM
This makes me think of golf course in the artic or a Jamaican bob sled team.
Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on September 10, 2022, 09:54:11 AM
Quote
I used to live in the worst HOA ever - military housing.  After that I lived in a house on the national register, no visible antennas.  Then I lived in an apartment building with no yard and only a small community patio space.  I operated HF at all of them, and not one mag loop.

You were HOW OLD when you had these experiences?  Did they even have consumer mag loops back then?

Quote
Fast forward to today and operating "portable" often results in people buying small loops and highly loaded antenna contraptions which might offer a "match" but especially QRP are frustrating at best to make contacts with.  You spend more time futzing around setting up and adjusting these antennas than making contacts in the field.

As I clearly understand, there is a lot of "futzing" designing, installing, testing, tuning, retesting, rinse and repeat several times ad nauseum to get a long wire or any other "home brew" in a highly constrained location to work wellish.  Or I could futz less with something that works reasonably well while transmitting and receiving, but obviously not up to your self-imposed standard.

Quote
So from my perspective of over 40 years in this hobby operating HF in all manner of locations, you don't start with the poorest performing antennas, you go with the best performing ones you can possibly have.

And that is the key. 1) Your perspective after 40 years experience in making antennas 2) Your assumption that your "best performing" solution is achievable in my environment with my set of circumstances and abilities.

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Nearly always this will be a wire antenna.

With emphasis on "nearly" while ignoring other impinging and critical factors.

Quote
Sometimes you have no other choice but I wouldn't introduce limitations that don't actually exist.

Again, and this is key:  An assumptions that my "limitations...don't actually exist."  Do "age" and "physical abilities" count as "self-imposed?"  Is lack of 40 years in ham radio building antennas "self-imposed?"

Quote
What does "Fairly stealthy (mounted low, not conspicuous)" actually mean?  So a 3' loop on a stand is OK, but something like a nearly invisible wire or vertical isn't?

I was describing characteristics of a magnetic loop antenna.  Then you compared it to something I consider "infeasible" (long wire) due to my "self-imposed" (read allegedly "unreasonable") constraints.

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Would inconspicuous be OK?

Yes, that is one objective.  But not via something that I consider infeasible.

Quote
But there's a house, right?  Houses have height, length and depth, same dimensions as antennas.

Again, assuming that what is feasible for you is also feasible for me. My "house" is an attached multi-family condo in an HOA with heights that are a "no-go".

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Is in-shack tuning ruled out?

No.  In fact, that is a requirement for any antenna I install.

Quote
"Avoiding an antenna-building hobby" is a tight constraint.  You have a very specific set of operating conditions which demands a custom built solution.

"Demanding" a custom-built solution is based on your needs, expectations, objectives and capabilities.  Not everyone is you. The great thing about the ham radio or any hobby is that we don't need to react to the "demands" that are defined by someone else.

Quote
You are binding yourself to find the lowest common denominator solution, eliminating even simpler, less expensive and better performing ones.  Yes, you or someone else might have to build and install it (somehow you managed to get a G5RV jr on the roof...).

And that roof-mounted G5RV is not the type of project I care to repeat.

Again, "simpler" and "better performing" (based on my abilities and limitations) is from YOUR perspective and abilities. Such will not be "simpler" from my perspective. And while "better performing" is an ideal, it is irrelevant if not achievable based on my circumstances, abilities and constraints.

My "abilities" do not match yours.  My "limitations" do not match yours.  My limitations are not self-imposed, that is unless you consider age and level of physical abilities to climb and hang off ladders "self-imposed."

Quote
You just have to weigh the option of an expensive poor performer that's plug and play, or stretch a bit and end up with something that will offer a better operating experience.

Weighing I must.  Weighing I do.  All antennas are some level of compromise. "Poor performer" is relative to one's objectives and expectations. What is "poor performer" to an individual with 40 years in the hobby is not necessarily that to one who has different skills, abilities and unavoidable (not "self-imposed") constraints.

There are some here who would rather get on the air with more compromise than others rather than try to do what they are not capable of just because someone else believes differently.
Title: Re: Magnetic loop TX antennas
Post by: W9IQ on September 10, 2022, 10:52:04 AM
Remote tuning.  The antenna will be outside, 15 feet from my indoor shack location.  Having to go back and forth outside to tune it is a non-starter.

I notice that the couple of loops you have considered require tuning at the antenna in order to use them - that would classify them as a "non-starter". Also check any antenna your are considering to see if it is rated to be left outdoors - not many are.

A remotely tuned version is relatively expensive to buy although there are plenty of articles on the web for constructing the circuitry and mechanics to remotely adjust the tuning capacitor. If this is within your ability and interest to construct, you may be able to convert a non-starter to have your required features.

- Glenn W9IQ
Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on September 10, 2022, 11:26:52 AM
Remote tuning.  The antenna will be outside, 15 feet from my indoor shack location.  Having to go back and forth outside to tune it is a non-starter.

I notice that the couple of loops you have considered require tuning at the antenna in order to use them - that would classify them as a "non-starter". Also check any antenna your are considering to see if it is rated to be left outdoors - not many are.

A remotely tuned version is relatively expensive to buy although there are plenty of articles on the web for constructing the circuitry and mechanics to remotely adjust the tuning capacitor. If this is within your ability and interest to construct, you may be able to convert a non-starter to have your required features.

- Glenn W9IQ
Yes, you noticed correctly.  The more I learn about loops the more I understand those that won't work for me.   I will only consider remote-tuned loops capable of higher (100 watt or greater) power and designed for permanent outside deployment.  The only non-home-brew I am aware of that meets all three criteria for less than $800 are the MFJ-1782, 1784, 1786, 1788, and 1789.  And even those, according to reviews, should be considered semi-kits (as I mentioned in my OP) due to requiring fairly easy to fix QC issues.

I also wonder about the MFJ-2389 8-band "stealth vertical, aka "Ugly Stick" performance compared to the MFJ-1788 loop.   While I wouldn't consider the ugly stick because of it being, well, "ugly" (too many protruding elements at 12++++ feet up) it won't pass "stealth" objectives.  And, according to most reviews, after challenging assembly and tuning, the upper bands (60 and 80) are very narrow - bands the loop doesn't get anyway.  But the loops 20 to 40 meter bands are probably "at least" as narrow.
Title: Re: Magnetic loop TX antennas
Post by: AI5BC on September 10, 2022, 06:22:47 PM
I have some experience with STL's and would never go back. Here is what you get to look forward to. Forget about any kind of modern radio with a Panadapter, band scope, or scanning capabilities. You will have no use for such things because the bandwidth is so narrow on STL's, you will not see anything other than the frequency the antenna is tuned too. No spinning the dial looking for signals are in your future unless you can figure out how to synchronize both the antenna and radio at the same time. The bandwidth on some models is so narrow at the ends, they are only good for CW work. They make a great narrow band filter with an attenuator. 

Get yourself a cellphone and save your contacts phone number so you can call them and ask them to meet you on a specific frequency or get used to working NVIS Nets on specific frequencies. DX will only be something you read about.

Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on September 12, 2022, 07:49:50 AM
Thanks for the "heads up."

I understand there are compromises in every antenna system.  It's a matter of how many and what types of compromises one agrees to endure to get on the air.  I also understand that once folks who own an MFJ (a 1788, for example) get over fixing the QC issues, the great majority of reviewers believe it to be a worthwhile setup for their given situation.

In my "given situation", mag loops appear to be a viable option.

As for not being able to view the signal on a panadapter, I doubt that is the case with the RSPdx/SDRuno because the waterfall can be zoomed in quite a bit - 10kHz to one inch.
Title: Re: Magnetic loop TX antennas
Post by: AI5BC on September 12, 2022, 08:36:34 PM
As for not being able to view the signal on a panadapter, I doubt that is the case with the RSPdx/SDRuno because the waterfall can be zoomed in quite a bit - 10kHz to one inch.
Quit fooling yourself. Unless you have a dedicated HF antenna for the SDRuno, the SDR will be just as death as your HF rig receiver. If you had a dedicated or separate HF antenna, you would not need or want a mag loop. Your HF rig has a batter receiver. What makes you think a SDRUno is going to do better? Makes no difference what radio is in the shack with a death and mute antenna.
Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on September 13, 2022, 05:29:45 AM
I DO have a dedicated receive-only antenna for the SDR.

And you posed a red herring.  I never claimed the SDRuno is going to "do better." Where did you make that up from?  Avoid claiming I claimed what I never claimed.  It's unbecoming.  You do need to be more concise and accurate with your accusations.

I do write my share of stupid things, but that wasn't one of them.
Title: Re: Magnetic loop TX antennas
Post by: VE3PP on September 14, 2022, 05:05:25 AM
How far should a magnetic loop transmit antenna be kept from a metal chain link fence or from metal patio furniture?

I have a very constrained small patio area only 8' by 20' surrounded by chain link on two sides and concrete block walls on 2 sides.

I am looking at the Pracomm SML-1000-1.

I worked a guy in Poland on 15 M SSB one day who was using this antenna, mounted on the roof of his condo. He had it on a rotor. He was only running 100 watts and was 10/9 into SW Ontario. I have a 2 element tri band at 33 feet. So it is not like I have a big gun yagi way up in the air.
When he told me what antenna he was using I looked it up. And here it is! Mind you it is not cheap!

https://www.dxengineering.com/parts/mzz-baby

And here are the reviews posted on this site. As you can see the antenna gets a lot of good reviews.

https://www.eham.net/reviews/view-product?id=6666

You can watch this video

https://www.youtube.com/watch?v=N98uqdbnsc0
Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on September 14, 2022, 05:54:31 AM
Oh yeah.  That "baby" is made in Italy.  During Dave Casler's review of the MFJ-1788, he referred to that antenna and said "that ain't no baby."  The Mercedes of mag loops.  Maybe after I win the lottery. Oops.  Forgot. I don't play the lottery.
Title: Re: Magnetic loop TX antennas
Post by: K6BRN on September 14, 2022, 06:16:14 AM
Regarding a wire vs. magnetic loop...

I have to agree with Mark.  I've yet to see a residence where a good pre-made (solves the antenna building problem) multiband EFHW wire antenna could not be made to work, especially at the 100W and under level.  It takes some thought to lay it out and make it invisible if it's inside, and it's invariably a less than optimal arrangement, but that's done ONCE, while the magnetic loop is a constant excercise in movement and tuning.

If the wire can be moved into an attic space, so much the better.  And one HOA end-fed arrangement I had was outside and deployable - I unrolled it, hooked it to a tree, operated and rolled it back up.

One other concern with a magnetic loop is that IF a cheaper and smaller one is used, arcing might cause damage to the RF amp in the radio, even at low power (25 watts).

That said - nothing wrong with experimentation.  But it's always nice to have a "Plan B"

Brian - K6BRN
Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on September 14, 2022, 07:08:28 PM
Quote
And one HOA end-fed arrangement I had was outside and deployable - I unrolled it, hooked it to a tree, operated and rolled it back up.

That sounds like a somewhat repetitive task.  Especially if one has no trees, yard area or attic access.  I'd rather take a minute to retune from the comfort of my AC'd shack then to "redeploy" and "undeploy" each time I use HF.  That would put a huge damper on my operating.

Believe me, I would do "once and done" to achieve 15 to 40 meters if it was feasible for me at my location. May as well tell an elephant to levitate.
Title: Re: Magnetic loop TX antennas
Post by: AC7CW on September 15, 2022, 08:29:12 AM
One little-acknowledged fact about transmitting magloops is that they are only efficient when the loop circumference is a little less than a half wave. I find the whole idea of multi-band tuneable magloops offputting really: ridiculously low efficiency and narrow bandwidth are not good for much. Setting up a monoband transmitting loop for CW or for FT8 makes more sense to me and is almost the elegant solution for those situations perhaps if a low takeoff angle can be achieved without a tower.
Title: Re: Magnetic loop TX antennas
Post by: K6BRN on September 16, 2022, 08:33:44 AM
Quote
And one HOA end-fed arrangement I had was outside and deployable - I unrolled it, hooked it to a tree, operated and rolled it back up.

That sounds like a somewhat repetitive task.  Especially if one has no trees, yard area or attic access.  I'd rather take a minute to retune from the comfort of my AC'd shack then to "redeploy" and "undeploy" each time I use HF.  That would put a huge damper on my operating.

Believe me, I would do "once and done" to achieve 15 to 40 meters if it was feasible for me at my location. May as well tell an elephant to levitate.

I'm going to guess that you're in a Senior Assisted Living community, which puts pretty close oversight on residents, varying with their level of care chosen and apartment type.  Putting in ANY antenna can be pretty difficult under those circumstances and requires a lot of enterprise and effort which you do not seem to be in a position to supply.  I understand.

I hope the MagLoop works out for you.  If it doesn't, perhaps remote operation of a rented station will, and barring that, you at least have the forums.

Best Regards,

Brian - K6BRN
Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on September 16, 2022, 08:52:04 AM
Here are some widely acknowledged facts about mag loops for transmit in the 15 to 40 meter bands:

Cons: 


Pros:

Fair enough?

Quote
From K6BRN
I'm going to guess that you're in a Senior Assisted Living community, which puts pretty close oversight on residents, varying with their level of care chosen and apartment type.  Putting in ANY antenna can be pretty difficult under those circumstances and requires a lot of enterprise and effort which you do not seem to be in a position to supply.  I understand.

I am convinced you do NOT understand.  That was a rather ignorant , mocking, and disrespectful comment, Brian.  I have no doubt that was your intention.  When you grow up you will learn to understand that after a certain age we older folk are wise enough to know our limitations.  One does not to be in assisted living to understand and practice that.

Wise marketers of ham equipment will heed the facts:

Quote
...the average age of amateur radio operators is quite high. In some countries, the average age is over 80 years old, with most amateur radio operators earning their license in their 40s or 50s. https://www.liquisearch.com/amateur_radio_operator/demographics/age

Others such as yourself will just belittle and mock.
Title: Re: Magnetic loop TX antennas
Post by: W9IQ on September 16, 2022, 10:01:19 AM
All small loop antennas with uniform current start out with a peak directivity of 1.76 dBi (1.5 in linear terms) across the HF bands. It is the radiation resistance and the resistive losses of a particular antenna that determines the efficiency and thus the ultimately lowered gain of the antenna.

The radiation resistance is in direct proportion to the square root of the frequency so as frequency goes down, so does the radiation resistance and efficiency. You have no control over this. The radiation resistance is also directly proportional to the circumference of the loop. Here you can improve efficiency by selecting a larger circumference loop.

The construction details of a given loop determine the resistive losses caused by the RF resistance of the loop and its connections. So a larger diameter, better conducting tube and one with lower resistance connections will further improve efficiency.

So look past the marketeering claims and dig into the engineering details before selecting your antenna. You do have a great deal of control regarding the gain of the small loop you choose to deploy.

- Glenn W9IQ
Title: Re: Magnetic loop TX antennas
Post by: K6BRN on September 16, 2022, 10:37:35 AM
Hi Gerald (KK4GMU):

...
I am convinced you do NOT understand.  That was a rather ignorant , mocking, and disrespectful comment, Brian.  I have no doubt that was your intention.  When you grow up you will learn to understand that after a certain age we older folk are wise enough to know our limitations.  One does not to be in assisted living to understand and practice that.

You're right - I don't understand.  And you're VERY sensitive.  BTW - the second quote is not mine.  I don't care how old, what race or sex an operator is.  The stats are interesting, but nothing to perseverate over.

YOU need to understand - I'm not mocking you in any way and have been respectful of the nearly hermetic limitations you've placed on yourself.  Though I'm 13 years younger than you I'm VERY aware of the limitiations that have been remorselessly moving into my life.  Age is not to be mocked or laughed at - we all face that prospect, if we're lucky.

You've asked about magnetic loop antennas and pretty much received the same feedback over and over.  Clearly, you don't like the answers.  So I offered another option.  One that works for me in a very similar situation, and for others that I know.

You live in what is essentially a retirement state and are of retirement age.  And you've said you have no attic, etc. to put an antenna in.  Yet your registered address shows a home with a very nice peaked roof. low interior ceilings and presumably very good attic space for the antenna.  By code, there HAS to be access.  The Garage, by itself, looks workable, if the attic somehow isn't.  Doing the install yourself is not necessary - hire someone - many do that.  So you clearly have room for a wire antenna if you want one - but indicate its not workable.  Very odd.  If you simply don't like them, that's your preference - not something to argue.

So if you really live at your registered address, you have options.  If you don't, you're likely in a retirement community.  many are, in your state.  It's not a big deal nor does guessing at that denote disrespect.  It is what it is.  I visit Boynton Beach frequently for my own family reasons.

Assuming the worst intentions of people trying to help you is not a good path forward.  Perhaps at this point what you need to do is connect with other hams via a local ham club and share antenna solutions and installer info.  I always feel better when I have several options to try.  And locals always know the best people to help.  Plus, just talking to others with similar issues helps cheer me up  Maybe this will work for you, too.

One thing I've learned and am now applying liberally as I get older, is that paying others to do physical work that is now risky to me saves a lot of pain.  And pain is one of the penalties of age that is rarely emphasized in the brochures.  :)

Have a good day - life is short - and I know it.

Brian - K6BRN

Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on September 16, 2022, 11:48:58 AM
BTW - the second quote is not mine. 
Brian - K6BRN

This one?
Quote
Quote
...the average age of amateur radio operators is quite high. In some countries, the average age is over 80 years old, with most amateur radio operators earning their license in their 40s or 50s. https://www.liquisearch.com/amateur_radio_operator/demographics/age

Yes, I know.  That's why I added a link to it. Did you miss it? I hope it helps.

Quote
And you're VERY sensitive.

Sensitive when appropriate, yes. A presumptuous mocker when inappropriate, no.

Quote
You've asked about magnetic loop antennas and pretty much received the same feedback over and over.  Clearly, you don't like the answers.  So I offered another option. 
You're making this too much fun. ;D  You make one more erroneous assumption: You apparently believe that giving reasons  for choosing a given piece of equipment to help others understand the circumstances is disliking the answers.  Nope.  Giving reasons for choosing a given piece of equipment is NOT disliking the answers.  It is explaining the situations where use of a given piece of equipment may be most appropriate.  I understand there are those who lack an understanding of the logistical situation of some others - without assuming they are in "assisted living."  That was just a careless expression triggered by your disagreeing with my explanation.
Title: Re: Magnetic loop TX antennas
Post by: N8AUC on September 16, 2022, 02:09:20 PM
Well, all the information about mag loops I've seen on this thread are accurate.
They're going to be inefficient, and touchy to tune, especially at lower frequencies.
But experimentation is part of the game, so if you've got the spare cash, why not give it a whirl?

Unless you've got your heart set on being on 75/80 meters, another possible option is to get a couple of hamsticks and the mounting bracket that lets you use two of them as a dipole, and set that up on something like a painter's pole when you want to operate, and take it down when you're done. Now this won't work for 75/80 meters (i tried it and it was deaf as a post), but for 40 meters and up they work pretty good. Even better on 20 meters and up. And it's a lot less expensive than a mag loop. I know guys who operate on 20 meters who live in apartments, and they do pretty well with a hamstick dipole.

But if you must be on 75/80 meters, in my experience, nothing beats a wire antenna if you've got a limited budget.

Is there a wooden fence around what little yard you have, like a privacy fence? If so, you could build a wire loop that runs around the perimeter of the property. Granted it would be mainly an NVIS pattern, but I've known people who've done that and were satisfied with the results.

Just a suggestion.

73 de N8AUC
Eric

Title: Re: Magnetic loop TX antennas
Post by: K6BRN on September 16, 2022, 07:21:31 PM
Quote from: KK4GMU link=topic=137095.msg1273511#msg1273511

You're making this too much fun. ;D  You make one more erroneous assumption: You apparently believe that giving reasons  for choosing a given piece of equipment to help others understand the circumstances is disliking the answers.  Nope.  Giving reasons for choosing a given piece of equipment is NOT disliking the answers.  It is explaining the situations where use of a given piece of equipment may be most appropriate.  I understand there are those who lack an understanding of the logistical situation of some others - without assuming they are in "assisted living."  That was just a careless expression triggered by your disagreeing with my explanation.

Mmm.  Perhaps if nonsense is fun.

Seems like you already had the answers you wanted when you started the post.  Per Mark (K5LXP):

Quote
Expectation is a significant factor of your project here.  You've put a few unnecessary (in my opinion) constraints on the situation and in reading your message, there is only one possible conclusion.  That being the case, full steam ahead - get the loop, put it up and you'll decide if it works well enough for your goals.

The very attic-antenna-convenient structure of your home, open grounds and the statement that you tried laying a G5RV wire antenna directly on the roofing with less than satisfactory results pretty much says:  1. You really don't understand the opportunities you have, and/or 2. You just don't put much effort into putting up your antennas.

In that case, a magnetic loop is ideal, and I do understand.  Personal capability apparently has nothing to do with your approach - motivation vs. effort does.  And that's fine.  It's your station.  As pointed out by Mark, you get out of it what you put into it.  And experimentation is a great learning experience.

Meanwhile, my three stations are giving me great results - one of which is in an HOA with a structure not too different from yours that I operate FT8, SSB, FM and even occasionally AM from.  It uses a wire antenna.  I hope your magnetic loop solution works as well for you and that I hear you on the air.

BTW - what modes do you operate?  It does make a difference.  FT8 and CW punch through best with a compromise antenna.  But with recent very good propagation trends, you can have a great deal of fun with almost any antenna, efficient or not, on just about any mode, at the right time on the right band.

Have a good (remainder of) the day!  Mine was great.

Brian - K6BRN
Title: Re: Magnetic loop TX antennas
Post by: AI5BC on September 17, 2022, 09:44:55 AM
Brian is like Glen must be brothers. Both are old has-beens from the QRZ peanut gallery. They like pounding their elitist chest. They remind me of Biden. They should go back to hiding in the basement.
Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on September 17, 2022, 02:51:06 PM
Brian is like Glen must be brothers. Both are old has-beens from the QRZ peanut gallery. They like pounding their elitist chest. They remind me of Biden. They should go back to hiding in the basement.
That's a fair assessment and suggestion.

Some folks are absolutely convinced that they know what they don't know about every situation while making themselves feel better by diminishing others.  In this case ignorant assumptions that a fellow ham is in assisted living, is imposing "unnecessary constraints" and "lacks motivation" are made just because someone is considering use of a different antenna design.

Amazing!  Keep such folk far away from Elmerhood.
Title: Re: Magnetic loop TX antennas
Post by: W1RKW on September 18, 2022, 04:21:44 AM
in before the lock
Title: Re: Magnetic loop TX antennas
Post by: K6BRN on September 18, 2022, 08:18:30 AM
Brian is like Glen must be brothers.

Hi Brad.  I got quite a chuckle over that one.  But I'll take it as a complement.  Not brothers, but both Americans.  Glenn and I have our differences, but we manage to get along nonetheless without letting politics cloud things up too much.

Both are old has-beens from the QRZ peanut gallery.

Heh!  Yep.  That's pretty much the definition of "retired", which I've done a few times.  You should try it - its a nice place to be.  BTW - aren't you about the same age as me?  I think I have more hair, though.  :)

They like pounding their elitist chest.

More like I don't like to be "gaslighted" by someone who really wants attention - any attention - by way of asking for help, any help that they don't really want or need.  Elite?  I'm elite?  Wow.  Didn't know.  I need to get some better clothes, then.  :)

They remind me of Biden.

Ah, poor Joe.  He's doing his best, and as the oldest president in history, the job is not easy (not that it ever is).  I respected Reagan, too, who drifted into a similar situation over his terms.  A good man, true to his principles from day 1 to the very end.  A lot of people forget he was governor of CA, too, and had a very big impact on the state's future.  If you're ever out in CA, the Reagan library is a "must see". REALLY.

They should go back to hiding in the basement.

I love basements.  Every home should have one.  Great place for storage and for radio stations.  Keeps the garage from filling up with junk.  Don't spend much time in them, though - just got back from a trip around the USA and Canada.  Great to do now that COVID has died down a bit.  You really should get out more and see the world.

Maybe operate more, too.  Looks like neither you nor the OP actually do that much.  You had a great start with all the old Heathkit gear on your QRZ page.  The most fun I ever had was with an HW-101.  And propagation is Up again.  So maybe time for you to get back in the hobby.  Fun.  Constructive.  Lifts the spirits.  I don't think saying that is elitest ... just being a ham. 

Have a great day!

Brian - K6BRN

Title: Re: Magnetic loop TX antennas
Post by: N8TGQ on September 19, 2022, 04:18:27 AM
As far as you can.
Title: Re: Magnetic loop TX antennas
Post by: K3ZD on November 10, 2022, 10:49:27 AM
I bought a second hand MFJ 935B mag loop tuner just in case I need one some day since I live in a rental house and will probably downsize some day.  I works surprisingly well, especially on FT8 since you are on one frequency.  Had no trouble working Europe with a 4 ft loop of copper tubing on 15 meters.  If you like tuning around the band forget it since you'd have to sit next to it to constantly retune.  I endorse those who say try to get up a piece of wire outdoors any way you can.  I have a 70 ft length of stealth antenna wire running from a small tree to a bigger tree end fed and it works fine.  Getting an end fed random wire to work without RFI shack problems takes some knowledge but I have no problems.  I use a coax choke to keep RF off the shield, a low pass filter, one random length counterpoise wire and an antenna tuner.  No antennas are allowed here but no one seems to notice it or care and my neighbor is on the HOA.   
Title: Re: Magnetic loop TX antennas
Post by: K5TED on December 11, 2022, 11:34:10 AM
I ran a MFJ-1786 for years mounted to a short pole attached to a metal railing around the third floor balcony. Antenna was most efficiently tuned when perpendicular to the railing.

Worked all over the world from South Texas with 100w and that antenna. Phone and Digi.
Title: Re: Magnetic loop TX antennas
Post by: KF5KWO on December 12, 2022, 05:12:21 AM
I have had the MFJ-1786 for about 20 years now, have run it in the attics of a 3-story townhome and my current one-story home, off a second floor balcony on a 12-foot pole laid horizontally, and my current 12-feet off the ground on that same pole (erected vertically). It is my only antenna for 20m. It does fine outside, has a remote tuner, and is easy to take apart and clean and check once a year. It’s a bit pricey now, compared to when I originally bought it new back in the day. It handles up to 150 watts. Given the HOA situation you’re in, this antenna might be a good option for you.
Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on December 12, 2022, 01:05:59 PM
I have had the MFJ-1786 for about 20 years now, have run it in the attics of a 3-story townhome and my current one-story home, off a second floor balcony on a 12-foot pole laid horizontally, and my current 12-feet off the ground on that same pole (erected vertically). It is my only antenna for 20m. It does fine outside, has a remote tuner, and is easy to take apart and clean and check once a year. It’s a bit pricey now, compared to when I originally bought it new back in the day. It handles up to 150 watts. Given the HOA situation you’re in, this antenna might be a good option for you. [bold added for emphasis]

Thank you for sharing your experiences with your 1786 loop. I expect its arrival sometime in January from HRO. 

Many here encourage trying a wire (70' more or less) or some form of home brew device based on their own experience, version of a good time, operational priorities and size/layout of their property which in my case all of which most likely differs greatly from theirs.
Title: Re: Magnetic loop TX antennas
Post by: N4UFO on December 13, 2022, 03:14:10 PM
I got curious about mag loops (or STLs as some say they are more appropriately called - Small Transmitting Loops) a few years back and did some reading. Once I understood the theory vis-a-vis the 'golden triangle of antennas ( efficiency, small size, wide bandwidth - pick TWO) it made sense and I desired to try them out. So I first got an MFJ-935B and made some loops out of copper tubing and experimented. Not enough though, I am afraid... but what I did do showed very promising results.

When we moved cross country and into an apartment I took a certain government check sent to everyone and handed it over for an MFJ-1786 to use at the apartment we had rented. Unfortunately again, my 'play' was cut short by some very sensitive AFCI breakers. And once we were able to buy a house and move in, I found the numerous trees around to be good supports for wire antennas. One of which I built was a set of vertical wires with the feedpoint mounted at the top of a wooden fence going up to a tree limb. Each band had two radials going down the back side of the fence, spaced the same distance apart as the vertical portion. This is a very good, well tuned antenna that talks all over the world.

So... after finding a good deal on a reliable TV rotor I had used before AND being bored, I decided to get the MFJ-1786 out of storage and do some experimenting. I mounted 3' tripod on a weighted down wood pallet in the yard with a 4' mast that had the rotor and a lateral support bearing mounted to it. Then I went up with a typical 4.5' TV mast to the loop. All-in-all it was about 8 foot above ground and rotatable. Let the fun begin!

What did I discover? Well, first thing I did on the antenna was work a Malawi DXpedition on 10m FT8 that I had been unsuccessful up until then with my vertical wires. This can be attributed to other things, of course, but I did a lot of A/B testing after that. Bottom line, if I point the 'end' of the loop at a station, I would observe 2 S  units better reception over the vertical wires and a 2-3 S unit decrease when I aimed the broadside nulls at the same station. This repeated fairly consistently. BUT... the wires seemed to be much quieter than the loop, thus negating the 'advantage' when aimed at a station. This was atmospheric noise and not local noise. However, if I DID have say, some local electrical noise or RFI, aiming the loop with the null towards the noise would be a great advantage to working some stations.

My original hope was to use the 'directional advantage' of the loop to aid me in working DX stations. But the noise difference seems to make it a draw and the loop has no advantage, thus far, over the wires. What I have NOT experimented with enough is issues of take off angle... local versus distance, etc. I have a 20 ft cliff and then a metal barn just beyond the edge on top of that cliff/rise which is only about 50 feet behind my wires to the south. I would like to use the loop to work more SA on 10m and see if it helps with a higher angle due to reflection off the nearby ground.

So, there may yet be some advantages to the loop I don't yet know about. BUT, I have recently purchased a lightweight 6m yagi and may use a second slip on mast and put the yagi up in place of the loop. So, no telling if/when I will get around to experimenting more. But MAKE NOTE. I am not taking down the loop because it is not a good antenna... I am taking it down because it is NO BETTER than my vertical wire antennas. It is a GOOD antenna, in spite of what some think because of it's size.

The 'triangle' I mentioned... pick two? Obviously, it's Efficiency and Small size. The Bandwidth is VERY narrow... BUT it's remote tunable!!! So that makes up somewhat for the narrow bandwidth curve. It would not be a great 'scan the bands' antenna... but it a day & time when modes like FT8 & FT4 are popular, one can tune up on a band and sit there for hours watching/working other stations. Or occasionally QSY to another band. I seem to be able to do that to a nearby band within a cycle or two (30 seconds). Going from 30m to 10m or vice versa might take a little longer.

Enjoy your loop! I highly recommend that if you mount it horizontal, put it 20 feet or more above ground... if vertical, leave it rotatable, whether remotely with a small rotor or armstrong by hand.  :)

As always... your mileage may vary.  ;)  Wow! 6m is open... wish I had the beam up already!  :D
Title: Re: Magnetic loop TX antennas
Post by: KA4WJA on December 13, 2022, 03:28:48 PM
Jerry,
1)  Yes, you are correct that many of your fellow hams' situations / locations / applications may be vastly different than yours....and, you desiring to try something that better "fits" your situation / application is fine.  :) 
And, I think we all wish you good luck in your choices!  :)

Many here encourage trying a wire (70' more or less) or some form of home brew device based on their own experience, version of a good time, operational priorities and size/layout of their property which in my case all of which most likely differs greatly from theirs.

But....(don't you just love it when someone says they agree with you and then they add a "but"?)


2)  But, I would like to politely point out 2 important things:

a)  that there are some hams here-about (myself included) that have many decades of experience and many years of education in these very matters / in these very same situations....so, some of the advice / recommends that you get from these folks are not only well-intentioned and/or based on those personal experiences, but also based on the "physics" of RF / Antennas, not trying to dissuade you from any particular antenna, nor steer you away from experimenting.

b)   the "physics" of RF, antennas, etc.....actually getting radio-frequency energy (RF) from your radio transmitter, efficiently out into the ether / atmosphere.....well, this is well understood (and has been for many decades), and while some salesmen might try to hype their newest / greatest antenna, etc., please remember the new ham doesn't need to understand all of the "physics" here, as long as they grasp the rather blunt (but truthful) adages of:  "you don't get something for nothing" and "there's no such thing as a free lunch", "the wheel doesn't need reinventing", etc....

c)  just about ANYTHING metallic can be used as an antenna.....it's all a matter of degree!
(if what you buy/install is good enough for you...cool....but, if you want "better", there are "better", that don't cost as much, etc.


Sure, a good understanding of the "physics" of all of this would be great....but, until then, please just accept these facts above.  :)



3)  Jerry, I truly wish I was back home (just ~ 10 miles from you), where I'd happily stop over and offer to help / experiment, etc....and especially to help you save money on boondoggle's!
(Maybe next month?)


Anyway, fair winds, good luck, and 73,
John,  KA4WJA
Title: Re: Magnetic loop TX antennas
Post by: K6BRN on December 13, 2022, 04:32:08 PM
Hi Gerald (KK4GMU):

I see its December and you still won't have your antenna up until at least January.  Bummer!  (I love operating during the holidays). Regardless, you'll get there.  Just be persistent.  I'm sure they'll be a lot of learning along the way.  It's part of this hobby and fun by itself.

Please let us know how the MFJ loop performs when you have some time on it.

Following up on our much earlier conversation months ago, I've moved my EFHW-4010-2K into the attic of my East Coast townhome (QTH#2).  This was necessary because the tree it was run out too previously came down.  Ooops!  What to do?

Normally I don't care for attic antennas due to possible RFI/EMI issues, but I thought I'd give it a try.

The townhome has a pretty high roof peak, just like yours.  So I moved the antenna into the attic and folded it's 63-foot length into a (more or less) horizonal V, with the apex elevated to the roof apex furthest from the adjacent unit and the ends at just above ceiling height close to the adjacent unit.  The apex is pointing nearly due West.  There was a few feet left over after forming the "V" so I just bent it in the direction of forming a "delta" shape.  Then I placed a pretty hefty common mode choke about 4-6 feet from the feed-point and another at the operating station, three levels below.  To my great surprise, it works quite well with no apparent RFI/EMI issues - at least up to the 500 Watts I've pumped into the 75 feet of feedline.  And it's apparently (roughly) omnidirectional.

In the current great propagation, I've made contacts worldwide on FT8 with ease, and haven't had too much trouble talking to Europe and the West Coast on SSB (depends on the band and day).  There is some heating of the 49:1 matching transformer on 40M and some in the attic CMC as well when running QRO for extended periods, so antenna efficiency is less than perfect.  But it seems more than good enough and receives very well. too.

Your condo is single level, so I'd probably avoid placing the antenna apex directly over the operating station if I were to try the same there.

This might be one other possibility to consider during your adventures.  Which are likely to continue for some time if you stay in the hobby - they're half the fun.  You did ask for relevant personal antenna experiences in this thread a while back.  So I thought I'd contribute the results of my latest condo-living-as-a-ham-in-an-HOA experiment.

Happy Holidays!

Brian - K6BRN
Title: Re: Magnetic loop TX antennas
Post by: N2ZD on December 17, 2022, 09:36:22 PM

  A lot of naysayers out there. I bought a Ciro Mazzoni Loop which covers 10 thru 40m.
 I figured I would give it a try since I'm now in a HOA and see how it does. Well, it works fantastic for what it is.

    I worked around the world using 100 watts with it set up on my driveway. Now here is the fun part. One day I was farting around with my FT817 and hooked it up to my Mazzoni. With 5 watts, I worked 10 countries on 10m,17m,20m. in one hour. It was set up on the Tripod, 5 feet high at the antenna base. Although this antenna is quite expensive, it does work. It tunes using a box that sends a small RF signal up the coax which returns if the swr is greater than 1.1, then antenna will adjust the size of the loop accordingly in order to couple or decouple the air capacitor on top. This is usually accomplished in under 10 seconds.

   The caveat is its expensive, its big, but in contrast,  it doesn't look like a typical antenna. But can be made to look like a SAT antenna with a gray cover or just lay it down when you're done using it.

  Anyway, one can assemble a sub-100 watt version for less than a few hundred bucks using a suitable vacuum variable capacitor. The MFJ one works, if you can find one in good shape. Is it a compromise? Yes, but a fun one. Most DX stations love to work QRP stations at 5 watts. Most rag chewers will enjoy the contact as well.

  I've also had decent luck using a 5:1 balun and rain gutters. Hidden or compromised Dipoles, and a 5BTV on a foldable mast at my previous qth. For my next trick, I'll sink a WillBurt in my yard for "Up at Night, then out of sight"

Regards Richy N2ZD

 
Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on December 21, 2022, 04:10:14 PM
Thanks John for looking out for me.

And Richy, I appreciate your sharing your successful experiences with your Mazzoni.  I'm expecting to receive my "poor man's Mazzoni", the MFJ-1786 (a bit more difficult to tune than the Mazzy) I've had on order since October and expect to receive in January.  Looking forward to the adventure.

I've installed and set up a couple of digital apps (WSJT-X and JS8Call - integrated with Win4Icom) and am familiarizing myself with them in anticipation.
Title: Re: Magnetic loop TX antennas
Post by: N2ZD on February 01, 2023, 11:29:18 PM

  Here's a cool story... I have the Ciro Mazzoni baby loop. It covers 10 thru 40 m. It works so good,I wanted the Larger midi loop which covers 20 to 80m. While on facebook, one popped up near Cape Canaveral. Nailed it for super cheap! Got it from a guy who took it down for the wife of an SK. I'm cleaning it up now and straightening the fins on the air cap as he was a little rough when taking it down. No biggie as the aluminum is very soft.
   I'm making two tilt over bases (for each one) and covering them with some plastic camo plants from hobby lobby and "planting" them in my garden. 
Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on February 02, 2023, 09:33:36 PM
I'm about to throw in the towel regarding the MFJ-1786 I ordered last October that was supposed to be shipped in December.  I paid up front for it.  With short term CDs over 4%, HRO is profiting off the interest on my nearly $600 payment.  The passing of 4 months with no delivery date in sight has given me time to consider other ham hobby options. 

I have an Anytone 878 DMR HT expected in the mail tomorrow.  DMRs are complex enough to occupy me for some time and will satisfy the antenna-restricted aspect of the hobby for the forseeable future.
Title: Re: Magnetic loop TX antennas
Post by: K5LXP on February 03, 2023, 05:01:50 AM
Per repeaterbook there's a DMR repeater about 10 miles from your QTH.  Maybe not "armchair copy" with an HT depending on it's coverage but at least something to start with.

Mark K5LXP
Albuquerque, NM
Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on February 03, 2023, 06:41:46 AM
Per repeaterbook there's a DMR repeater about 10 miles from your QTH.  Maybe not "armchair copy" with an HT depending on it's coverage but at least something to start with.

Mark K5LXP
Albuquerque, NM

That repeater is on a lowish tower and located about 15 miles from my QTH.  Hams in my neighborhood have no success in reaching it.  Consequently I'm researching "hot spots" (see thread under 'Digital').  The total cost of the DMR radio and hotspot will approach the refund for my non-existant mag loop.
Title: Re: Magnetic loop TX antennas
Post by: KA4WJA on February 03, 2023, 09:53:42 AM
Jerry,
All opinions here are valid in their own context / in their own specific situations....but, as I'm local to you, I hope my opinions here might have been ever so slightly more impactful?
With that in mind, I'm going to go out on a limb here and make some blanket statements (with no intention of arrogance)...


Some of this new post of yours, is great news to many of us!   
(although, spending $600 and not getting your product that you ordered is not great, actually getting your money back on a fairly inefficient / poor performing antenna....AND the ability to actually install a better/more efficient/more effective antenna, for ~ 10% - 20% of the cost of this MFJ piece of junk, is great!)
I'm about to throw in the towel regarding the MFJ-1786 I ordered last October that was supposed to be shipped in December.  I paid up front for it.  With short term CDs over 4%, HRO is profiting off the interest on my nearly $600 payment.  The passing of 4 months with no delivery date in sight has given me time to consider other ham hobby options.

To be clear, as I have said/written for decades, "anything metallic" can be an antenna, and can "work" to some degree...it's all a compromise!  :)
The basic calculations come down to:
a)  what you want to do / who you want to communicate with (as well as on what bands, what time of day/year, etc.)
b)  how much room do you have for an antenna / HOA restrictions
c)  how much money can you spend on antennas (remember the old 90/10 or 80/20 rule!)

And, taking into consideration much of what you've written over the past year (your townhome, HOA issues, RFI, etc.), we can it seems clear to all of us that:
----  a simple antenna (even small/inefficient) OUTSIDE and in the clear will work better than one inside/in attic...
---- a simple outdoor wire antenna (like a 40m inverted-v), even at low / unobtrusive height, would be a great antenna for you...
---- if you require more "multi-band" operations, a remote-tuner-fed doublet (based on the simple dipole / inverted-v just mentioned, would be an excellent choice for you.   (this is especially true with your having an IC-7100, which allows simple, seamless, easy-peasy multi-band operation of an Icom AH-4 remote tuner)

And....
And, Jerry, I'm going for it here....
Forget most of the BS propagated here abouts.....and get an AH-4 (and some coax and control wire) and some scrap wire.....throw it up just about anywhere, at any height and in any configuration you can manage....one wire to the AH-4's "antenna terminal" and one wire to the AH-4's "ground terminal", and you have a remote-tuner-fed-doublet/dipole....easy-peasy!

I know I should have been this insistent last year, but you seemed so strident in pushing back against anything that was suggested here if it didn't get the approval of those in EMCOMM, I thought better of being too forceful.
But, at this point, I figure you're more open about things?
So...

So, scarp the BS ideas, and actually do what I've been recommending for decades.  :)

You know it was in the early 1970's that I was taught a rather simple ham radio rule-of-thumb:  "If all else fails, try a dipole....or save yourself the headaches, and just try a dipole first!"
And...

And, if you combine the above with my many decades of personal, hands-on, experience with remote-tuner-fed antennas, perhaps you'll feel confident that my advice here is sound?

If not, no worries....but, darn Jerry....now that you've seen the errors of the BS / crappy antennas, why not try something that actually works? 
Just saying....now's the time!  :)


As for DMR....not my cup-of-tea....but, I do know that like D-star, the DMR and D-star activity in Ocala is very limited and populated by some fairly narrow-focused folks (most socialable types will get bored pretty quickly with Ocala "digital" operations)....
I have an Anytone 878 DMR HT expected in the mail tomorrow.  DMRs are complex enough to occupy me for some time and will satisfy the antenna-restricted aspect of the hobby for the forseeable future.



BTW, on a final note on HF antennas.....please remember that your receive S/N is the most important aspect!  (and, while my focus above was more "transmit" centric, the fact is if you put together a remote-tuner-fed-doublet/dipole and use a good CMC/Current balun on the coax, right at the AH-4 tuner, you'll reduce much of the "antenna system caused - RFI")

Okay, there is more (a LOT more), but I really have to go...
Take care my friend!

73,
John,  KA4WJA


P.S.  I'm sure some here will argue in favor of "small transmit loops", etc...saying I don't know what I'm talking about....but, please have a close read guys....I AM upfront saying that ANYTHING can work....it's all a matter of degree!  :)
Oh, and I'm also clear that I don't think varying opinions are a bad thing. 
Title: Re: Magnetic loop TX antennas
Post by: KA4WJA on February 03, 2023, 11:10:50 AM
Too late to edit...so, I will clarify...
Enjoy the minor clarifications....

Jerry,
All opinions here are valid in their own context / in their own specific situations....but, as I'm local to you, I hope my opinions here might have been ever so slightly more impactful?
With that in mind, I'm going to go out on a limb here and make some blanket statements (with no intention of arrogance)...


Some of this new post of yours, is great news to many of us!   
(although, spending $600 and not getting your product that you ordered is not great, actually getting your money back on a fairly inefficient / poor performing antenna....AND the ability to actually install a better/more efficient/more effective antenna, for ~ 10% - 20% [assuming my example of 40m inverted-v] of the cost of this MFJ piece of junk, is great!)
I'm about to throw in the towel regarding the MFJ-1786 I ordered last October that was supposed to be shipped in December.  I paid up front for it.  With short term CDs over 4%, HRO is profiting off the interest on my nearly $600 payment.  The passing of 4 months with no delivery date in sight has given me time to consider other ham hobby options.

To be clear, as I have said/written for decades, "anything metallic" can be an antenna, and can "work" to some degree...it's all a compromise!  :)
The basic calculations come down to:
a)  what you want to do / who you want to communicate with (as well as on what bands, what time of day/year, etc.)
b)  how much room do you have for an antenna / HOA restrictions
c)  how much money can you spend on antennas (remember the old 90/10 or 80/20 rule!)

And, taking into consideration much of what you've written over the past year (your townhome, HOA issues, RFI, etc.), we can make some darn good suggestions / it seems clear to all of us that:
----  a simple antenna (even small/inefficient) OUTSIDE and in the clear will work better than one inside/in attic...

---- a simple outdoor wire antenna (like a 40m inverted-v), even at low / unobtrusive height, would be a great antenna for you...even if not configured "straight", etc....a simple, center-fed dipole or inverted-v is a good antenna, and a damn inexpensive one! And, it alone will work well on both 40m and 15m...and adding two small wires for 20m, making a 40m, 20, 15m "fan-dipole" is also easy-peasy, cheap and requires NO special tools/equipment, no "tuners", no "antenna analyzers", etc....nope, nothing like that needed at all!  :)

---- if you require more "multi-band" operations (like full HF coverage, from 80m thru 10m), a remote-tuner-fed doublet (based on the simple dipole / inverted-v just mentioned, would be an excellent choice for you.   (this is especially true with your having an IC-7100, which allows simple, seamless, easy-peasy multi-band operation of an Icom AH-4 remote tuner)  (yes, an Icom AH-4 will cost ~ $300 - $350, new...and, ~ $200 used....but, that's a total net cost of ~ $100 - $150 if you decide to sell it after a couple years....and, this (along with a couple ~ 30' lengths of scrap hook-up wire) is damned cheap for an effective antenna in HOA areas....

And....
And, Jerry, I'm going for it here....
Forget most of the BS propagated here abouts.....try a 40m dipole / inverted-v first....or, if you do require full 80m - 10m coverage, AND can accept a small grey box outside on your fence or on a pole, with just two small ("barely visible") wire coming out of it....  get an AH-4 (and some coax and control wire) and some scrap wire.....throw it up just about anywhere, at any height and in any configuration you can manage....one wire to the AH-4's "antenna terminal" and one wire to the AH-4's "ground terminal", and you have a remote-tuner-fed-doublet/dipole....easy-peasy!

I know I should have been this insistent last year, but you seemed so strident in pushing back against anything that was suggested here if it didn't get the approval of those in EMCOMM, I thought better of being too forceful.
But, at this point, I figure you're more open about things?
So...

So, scarp the BS ideas, and actually do what I've been recommending for decades.  :)

You know it was in the early 1970's that I was taught a rather simple ham radio rule-of-thumb:  "If all else fails, try a dipole....or save yourself the headaches, and just try a dipole first!"
And...

And, if you combine the above with my many decades of personal, hands-on, experience with remote-tuner-fed antennas, perhaps you'll feel confident that my advice here is sound?
FYI, my first experience installing / working-on and with remote-tuners and remote-tuner-fed antennas was in 1973....yep, 1973! (those were not "auto-tuners", but rather remote-controlled / stepper-motor driven tuners with a tapped inductor and a couple dozen variable caps that all needed "pre-tuning".....it was in/near 1980-1985 that I started with remote auto-tuners, like Icom AT-120 and AH-2...then the AT-130 and AT-140, and AH-4, as well as SGC tuners....and still use Icom AT-140's and SGC tuners today!!
If not, no worries....but, darn Jerry....now that you've seen the errors of the BS / crappy antennas, why not try something that actually works? 
Just saying....now's the time!  :)


As for DMR....not my cup-of-tea....but, I do know that like D-star, the DMR and D-star activity in Ocala is very limited and populated by some fairly narrow-focused folks (most socialable types will get bored pretty quickly with Ocala "digital" operations)....
I have an Anytone 878 DMR HT expected in the mail tomorrow.  DMRs are complex enough to occupy me for some time and will satisfy the antenna-restricted aspect of the hobby for the forseeable future.



BTW, on a final note on HF antennas.....please remember that your receive S/N is the most important aspect!  (and, while my focus above was more "transmit" centric, the fact is if you put together a remote-tuner-fed-doublet/dipole and use a good CMC/Current balun on the coax, right at the AH-4 tuner, you'll reduce much of the "antenna system caused - RFI")

Okay, there is more (a LOT more), but I really have to go...
Take care my friend!

73,
John,  KA4WJA


P.S.  I'm sure some here will argue in favor of "small transmit loops", etc...saying I don't know what I'm talking about....but, please have a close read guys....I AM upfront saying that ANYTHING can work....it's all a matter of degree!  :)
Oh, and I'm also clear that I don't think varying opinions are a bad thing.

73,
John,  KA4WJA
Title: Re: Magnetic loop TX antennas
Post by: N2ZD on February 03, 2023, 11:20:58 PM

 Ok, new story for today.

   I don’t like “bitch slapping” anyone about these loops. So I’ll tell you about the MFJ 1788 loop.
   One of my fellow HOA members had one up for sale and we did some trading. So I popped it on my Ciro Mazzoni tripod in my back yard and commenced playing with it.
   The nice thing about the MFJ loop is the coax powered motor so less wires and more portability. It’s lightweight and great for those who want to set up at a campsite or in a park.
    First shot Florida to Missouri on 40m. No problem with 20 watts.
    Simply use the coarse adjustments to get the “blip”  then the fine adjustments to get the best match. A little tricky until you get used to it.
    I don’t know why you people get hung up on Q. It’s easy to get it rematched after you know the syntax of the control box.
   I have three loops, the two in operation (MFJ and Ciro Mazzoni baby loop)  I’m having a ball with. I’m working more stations with a loop than I could ever imagine.
     Even with the 817 and 5 watts I’m kicking ass. I agree that they are a compromise, but they do work and they’ll get you on the air.

Regards Richy N2ZD
Title: Re: Magnetic loop TX antennas
Post by: K6BRN on February 03, 2023, 11:57:13 PM
Hi Richy:

Sounds to me like MFJ did most of the "slapping" of the O.P.  No big surprise.  John is just trying to be helpful as were others offering advice, which WAS solicited in the first place.  Nobody's a "victim" in this.

Regarding loops - excellent.  Glad you like them and QRP/semi QRP, which is what they support.

I'm pretty happy too, largely due to the incredible propagation conditions we're having.

Worked 230+ stations today, most FT8 but many SSB as well, with longest shot being to South Africa at over 10K miles.  Had a "pipe" all morning from the West to east coast on 10M/SSB, too.  All with 100 Watts and a wire (EFHW-8010-2K), on 10-80M, including WARC.  Some of the openings, like SA, popped up for just a moment, then vanished.  Have to be quick and on-topic to catch those.

I imagine you and your loops are doing great, too.

These great conditions will not last indefinitely, and if the O.P. (or anybody else) really wants to get into Amateur Radio/HF and have some DX fun, this is THE time to do it.  But it takes effort and experimentation to find out what works best for YOU, especially where antennas are concerned.   But also with modes, bands AND networking with others.  As with all efforts in life, hobbies or otherwise, you get back what you put in, and if you're not willing to do some work, sift carefully through the advice of others and have some patience in trying to succeed, disappointment will follow - no matter WHAT direction you go in.

Pretty obvious stuff, right?

Brian - K6BRN
Title: Re: Magnetic loop TX antennas
Post by: N2ZD on February 04, 2023, 08:17:47 AM

 That’s great! I love 10m, it’s my favorite band when it’s open. It’s usually good at times, but a lot of people opt for 20,40, 17 so unless you call you’ll never know if it’s open.lol..

   I’m having trouble with the MFJ on 10m, the Ciro OTOH tunes right up, so I have to mess around with the MFJ 1788 to see what’s going on.
   I also have the other MFJ loop that you manually tune. I haven’t used it yet, as I forgot I had it lol.
     I have a Hustler 5 BTV, and a 130 foot EFHW, a gaggle of screwdrivers, some Outbackers etc. But I have to keep a watchful eye out for the HOA police as they say when they are deployed…
   I also have a bunch of amps as well, but I’m trying to stay low key here which is part of the fun. I like running low power, off of batteries and my loops just to see how far I can get out.

Regards Richy N2ZD

     
Title: Re: Magnetic loop TX antennas
Post by: K6BRN on February 04, 2023, 10:12:53 AM
That’s great! I love 10m, it’s my favorite band when it’s open. It’s usually good at times, but a lot of people opt for 20,40, 17 so unless you call you’ll never know if it’s open.lol..

Hi Richy:

I understand the HOA struggle!

BTW ....

One good way to see if any HF band is likely open and to where is by looking at this MUF (Maximum Usable Frequency) map, updated every 15 minutes:

https://prop.kc2g.com/

And if you're active on FT8, PSKReporter will tell you who is hearing you and where, and what your signal report is:

https://pskreporter.info/pskmap.html

Have fun!

Brian - K6BRN
Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on February 19, 2023, 08:25:38 AM
Jerry,
All opinions here are valid in their own context / in their own specific situations....
True

Quote
b)  how much room do you have for an antenna / HOA restrictions
c)  how much money can you spend on antennas (remember the old 90/10 or 80/20 rule!)
These are the factors that may be difficult to imagine by those who are not fully aware of my constrained site and my current interests in the hobby.

Quote
As for DMR....not my cup-of-tea....but, I do know that like D-star, the DMR and D-star activity in Ocala is very limited and populated by some fairly narrow-focused folks (most socialable types will get bored pretty quickly with Ocala "digital" operations)....
Surprisingly to me, and maybe to you, too, there are quite a few very local DMR folk.  I was on a couple of local VHF nets and asked about DMR.  There were three hams within two miles who were into DMR and offered assistance.  Within 10 miles there are many more.  DMR is not restricted to "Ocala digital operations."  DMR is the HOA "victim's" answer to getting to dozens of states and countries.  True, many hams do not consider DMR "real radio".  Much of the same can be done on a computer WITHOUT a radio.  But for me and many others, it is an aspect of ham radio that is a lot of enjoyment while being a healthy challenge.

Being an antenna and propagation expert, your comfort and knowledge levels are definitely in those areas.  Thank you for your suggestions which I would likely implement if I was as interested in that segment of the hobby as you are.
Title: Re: Magnetic loop TX antennas
Post by: N2ZD on February 19, 2023, 09:01:37 AM

BTW, I made two errors lol! The loop I have is the 1786 and it doesn’t cover 10m. Nevertheless it works good but is touchy to tune.
   The 1788 covers 10m but not 40m. I’d rather have 40m for all intents and purposes because it’s easy enough to hang a dipole or pop up an imax for 10m and then lower it when done.. lol
   
   
Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on February 19, 2023, 09:10:54 AM

BTW, I made two errors lol! The loop I have is the 1786 and it doesn’t cover 10m. Nevertheless it works good but is touchy to tune.
   The 1788 covers 10m but not 40m. I’d rather have 40m for all intents and purposes because it’s easy enough to hang a dipole or pop up an imax for 10m and then lower it when done.. lol
Take a look at the specs again.  I think you had it right the first time:

1788:  15 to 40 meters
1786:  10 to 30 meters.

From MFJ website:
MFJ-1786, SUPER HI-Q LOOP, 36~ DIA, 10-30 MHz
https://mfjenterprises.com/collections/all/products/mfj-1786
Title: Re: Magnetic loop TX antennas
Post by: AI5BC on February 19, 2023, 02:34:35 PM
I played around with a mag loop for a while out of curiosity, but I would never want another one under any circumstances. They work, but so does WDC. Lots of opportunity for improvement. Now for the part I like, time for Debbie Downer. STL's are extremely narrow banded. So much so operating at the ends, only practical for CW. That nice new radio you have with a band scope is useless to you. The antenna is stone death to all frequencies except the one the antenna is tuned too.

I know a couple more hams who did not know that before the emptied their wallets. Should have seen the look on their faces when they discovered it.

(https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse1.mm.bing.net%2Fth%3Fid%3DOIP.pSMmCokjdhhZsC1U0UmlUgAAAA%26pid%3DApi&f=1&ipt=124ed8626dc108d2ccddb852f83c2f504c28e6503e8efd326da4ce33d9dbef11&ipo=images)
Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on February 21, 2023, 11:01:53 AM

I know a couple more hams who did not know that before the emptied their wallets. Should have seen the look on their faces when they discovered it.

(https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse1.mm.bing.net%2Fth%3Fid%3DOIP.pSMmCokjdhhZsC1U0UmlUgAAAA%26pid%3DApi&f=1&ipt=124ed8626dc108d2ccddb852f83c2f504c28e6503e8efd326da4ce33d9dbef11&ipo=images)

You mean the "oh s--t" look?  Yup. I've had it from time to time.  I suspect most experimenters have had it.  It's part of our learning experience.  Whatever doesn't kill us makes us stronger...or sometimes smarter.
Title: Re: Magnetic loop TX antennas
Post by: KA4WJA on February 21, 2023, 03:11:55 PM
Jerry,
1)  No worries here, and while there are some DMR folks around (and, yes I'm sure your assumption is correct ---- there are more now than a few years ago), as I wrote it's not really my cup-of-tea, so I don't keep up with it.  :)   But, I do grasp that this does give some folks in severely restricted housing, a way to experience some ham radio.

And, if DMR (and the ham socializing without radios) is of interest to you, don't forget our ham dinners (twice a month), etc.


2)  BTW, while 3 active DMR guys local to you is good, as well as "many more" within 10 miles of you....just to give you some numbers, there are ~ 2000+ hams within 10 miles of you (> 1600 in Marion, > 950 in Citrus, and > 200 in Levy counties....and with highest concentration of population of Marion being within a mile or so of you, I suspect ~ 2000 - 2500 hams within 10 miles of you)....and, another > 1300 hams in Lake county, just 15 - 25 miles from you...

Now those numbers might not impress those in Miami, Tampa, or Orlando (or SoCal or NYC) areas....but, think of the of the population differences....our 3 county population is just a little over half-million...so, having about 3000 hams, in a population of < 600,000 is > 1/2 percent of the population.....and, with total US ham population of ~ 767,000 out of a total population of ~ 330 Million, that's ~ 0.23 percent....so, our ham population (within our town and surrounding area, within 10 - 15 miles) is more than twice the national average!

And, while there are some "planned" and HOA-controlled communities, much of our area is not "planned", and the only ham restrictions (Ocala and Marion County, can't speak for Citrus, or Lake) are for ham radio antenna towers / structures > 150' tall....ham towers of 150' and below don't even require permitting nor inspection!   So, is it any wonder that we have such a high percentage of hams?  :)


3)  Jerry, please take this part in the friendly, helpful way I intend.

a)  there is room for everyone in ham radio, whatever your desires are....whatever niche you find inspires you, there is room for you!  (I have been saying this since the 1970's, and it is still as true today as it was 50 years ago!)

b)  just 'cuz I don't use DMR, etc., I will not try to dissuade you from what you find interesting.

---- BUT  ----

c)  But, if you do decide to get into HF operating from your house (using your IC-7100, etc.), please, please don't spend money on poor / inefficient antennas just because many hams say "I used xxxx, and it worked great" or "I've worked > 150 DX countries using yyyy antenna", etc....this is especially important in your case (both the negative of having serious HOA restrictions, and the positive of having a modern Icom rig), where you can take some small, nearly invisible wire, and string it up in just about any length (>20' and < 150'), in just about any configuration / shape (straight, zig-zag, loop, etc.), at just about any height (above your head, of course), and feed it from an Icom AH-4 tuner (under the eave, or on a post, or even just sitting on a patio table, etc.), and you'd have a decent 80m thru 10m antenna, easy-peasy, that will work much better than any small transmit loop (actually better than EFHW, and other such compromise antennas....and unless you put down a lot of radials in your yard for a vertical, it's going to work better than a screwdriver-antenna in your yard...and, for local/regional coverage, out to 300 - 500 miles, a vertical is the LAST type of antenna to consider!)....with total cost of ~ $300 - $325 new (or ~ $200 used)...

Also, please remember your initial query was about EMCOMM activities, etc....which, here-abouts in Florida are usually on 40m and 80m, with comms paths of ~ 50 - 300 miles....which would necessitate a horizontal antenna, not a vertical antenna (whether a "screwdriver" or a 65' tall full-sized 80m vertical)....a simple horizontal wire antenna will be MUCH better here!
Please take note here that I'm not panning verticals, nor screwdriver antennas....just pointing out that you can spend 2 - 4 times the cost of an AH-4 on some HOA-designed verticals, or screwdriver, etc....and, they'd be 20db - 40db worse than a simple horizontal wire antenna, for 40m and 80m coverage out to 300 miles or so!


{and, btw, remember the AH-4 tuner is well-sought after on the used market, as it is a MUCH better tuner than LDG or MFJ...so, while a ~ $600 - $800 transmitting loop may be a tough sell on the used market, even at 1/3 of its original price ---- an AH-4 can be sold for ~ 2/3 of its original price, in just a day or two....so, the "real" cost of an antenna using the AH-4 is much, much less than the poorer-performing small-transmit-loops!  :) }



d)  And, finally....again, if you do decide to get into HF operating from your house (using your IC-7100, etc.), please get in touch directly....and, whether you heed my specific recommendations or not will be no worry here, as long as you get the advice the choices are of course up to you.....the problem is that much of the advice given (goodness help me for saying this!) ---- much of it is rather anecdotal and misleading, and some of it is just regurgitating of either what that particular ham has heard from others (think of that old game of "telephone"), or just a rehash of the marketing info.

Remember, I'm not selling anything....and, I will usually only share my own experiences with some particular antenna / antenna system, AFTER I've helped explain the science / engineering (don't worry, maybe just the basics!)...


Okay, gotta' go.
Jerry, please take care and enjoy!

73,
John,  KA4WJA
Title: Re: Magnetic loop TX antennas
Post by: KK4GMU on February 21, 2023, 07:22:50 PM
Thanks, John.  Someday we'll meet in person.
Title: Re: Magnetic loop TX antennas
Post by: KA4WJA on February 21, 2023, 10:35:15 PM
Jerry,
You're welcome!

73,
John,  KA4WJA