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Author Topic: Magnetic loop TX antennas  (Read 1385 times)

N2ZD

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Re: Magnetic loop TX antennas
« Reply #45 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. 
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KK4GMU

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Re: Magnetic loop TX antennas
« Reply #46 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.
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K5LXP

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Re: Magnetic loop TX antennas
« Reply #47 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
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KK4GMU

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Re: Magnetic loop TX antennas
« Reply #48 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.
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KA4WJA

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Re: Magnetic loop TX antennas
« Reply #49 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. 
« Last Edit: February 03, 2023, 09:55:56 AM by KA4WJA »
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KA4WJA

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Re: Magnetic loop TX antennas
« Reply #50 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
« Last Edit: February 03, 2023, 11:28:54 AM by KA4WJA »
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N2ZD

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Re: Magnetic loop TX antennas
« Reply #51 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
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K6BRN

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Re: Magnetic loop TX antennas
« Reply #52 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
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N2ZD

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Re: Magnetic loop TX antennas
« Reply #53 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

     
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K6BRN

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Re: Magnetic loop TX antennas
« Reply #54 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
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KK4GMU

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Re: Magnetic loop TX antennas
« Reply #55 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.
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N2ZD

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Re: Magnetic loop TX antennas
« Reply #56 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
   
   
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KK4GMU

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Re: Magnetic loop TX antennas
« Reply #57 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
« Last Edit: February 19, 2023, 09:23:13 AM by KK4GMU »
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AI5BC

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Re: Magnetic loop TX antennas
« Reply #58 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.

« Last Edit: February 19, 2023, 02:38:15 PM by AI5BC »
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KK4GMU

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Re: Magnetic loop TX antennas
« Reply #59 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.



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.
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