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Re: Noise-Cancelling Passive Loop (NCPL)

 

¿ªÔÆÌåÓý

Thank you

From: [email protected] <[email protected]> on behalf of Martin - Southwest UK via groups.io <martin_ehrenfried@...>
Sent: Wednesday, September 11, 2024 2:40 AM
To: [email protected] <[email protected]>
Subject: Re: [loopantennas] Noise-Cancelling Passive Loop (NCPL)
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You will experience considerable differences between vertical and horizontal mounting, especially at low height above the ground. Vertical tends to perform better at low heights.
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I'd suggest modelling it for yourself, in order to see the effects, as it's too complicated to describe in detail in just a few paragraphs.
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4nec2 is free and you should be able to master the basics in a few hours. There is also a library of standard antenna designs
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Regards,
?
Martin
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Re: Noise-Cancelling Passive Loop (NCPL)

 

You will experience considerable differences between vertical and horizontal mounting, especially at low height above the ground. Vertical tends to perform better at low heights.
?
I'd suggest modelling it for yourself, in order to see the effects, as it's too complicated to describe in detail in just a few paragraphs.
?
4nec2 is free and you should be able to master the basics in a few hours. There is also a library of standard antenna designs
?
?
Regards,
?
Martin
?
?
Locked Re: MLA-30 clones

 

I guess you are replying to my deleted message on replacing the MLA-30 biastee with a passive one. I deleted the message because the images were missing when I viewed the message online after posting - however the text was intact. If you have received the message via email, can you tell me if the images were present?
I composed the message by dragging & dropping the images into the body. Perhaps I should have created a Photo folder of the images and then inserted the images by using the 'insert/edit link' function?
Back to your question. The replacement bias tee is detailed here:
https://sites.google.com/site/randomwok/Home/electronic-projects/test-equipment-accessories/a-cheap-biastee-for-active-loop-whip
However, it is a garden variety biastee and does not contribute to the observed noise reduction.?
Chin-Leong Lim, 9W2LC
Noise-Cancelling Passive Loop (NCPL)

 

Evening all,
I am working on building NCPL antennas. ?One question, what difference can I expect by laying it horizontal ?compared to vertical?

Also, Would it perform differently horizontally at different levels off the ground? On the ground 5 feet off the ground, 10 feet???
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TIA
Locked Re: MLA-30 clones

 

There's a lot of unwanted noise around 60 & 120KHz emanating from the DC-DC switcher in the Biasing Tee.
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You can obtain a similar improvement by adding a 1000uF capacitor across C2 in the biasing tee circuit.
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See toward the bottom of this archived webpage.
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https://web.archive.org/web/20230722120107/https://www.g8jnj.net/activeantennas.htm
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Regards,
?
Martin
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On Tue, Sep 10, 2024 at 10:26 AM, John K5MO wrote:

Impressive reduction in noise. Do you have a schematic of the replacement bias tee you used?
Locked Re: MLA-30 clones

 

Impressive reduction in noise. Do you have a schematic of the replacement bias tee you used?

Best
John


On Mon, Sep 9, 2024 at 10:32?AM biastee via <biastee=[email protected]> wrote:
I replaced the original biastee with a passive one and observed a significant reduction in noise.
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Details at:

Re: Improving my shortwave loop

 

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Thanks guys... if I stumble upon anything better I'll definitely pass it along.

Earl

On 9/9/24 19:17, John Spicer via groups.io wrote:

Sounds like a good build. Good luck signal hunting.

John

On Monday, September 9, 2024 at 06:25:38 PM EDT, W0LEV <davearea51a@...> wrote:


You've done about the best you can.? It's nearly a copy of my tuned loop I use only occasionally during lightning season.? The 450-foot long doublet has in the past supported a big thick blue spark up to and including 4 to 5 inches.? It is always disconnected when not in use.

Dave - W?LEV

Virus-free.

On Mon, Sep 9, 2024 at 9:57?PM Earl Parker II via <eparkerii=[email protected]> wrote:
Mostly by dumb luck I've managed to build a SW loop that seems to work well.? It's made of 1/2" OD copper tubing, about 34" across, with a 10" x 7 1/2" coupling loop made from 8 AWG copper wire about 1/16" (the thickness of a ty-wrap) from the main loop.? The coupling loop is connected to a dual banana female socket with banana connectors.? On the other end a 15' length of RG-58 goes from the BNC to the back of my radio.? The antenna has prominent nulls and is very directional.? Combining that with an old 3-section variable capacitor allows me to tune from ~4500 kHz to ~18000 kHz.
?
The only reason I went into the above is that I'm always looking for suggestions to make it even better.? If anyone sees anything I'm missing here I'd certainly appreciate hearing about it... thanks!
?
Earl


--
Dave - W?LEV
Re: Improving my shortwave loop

 

Sounds like a good build. Good luck signal hunting.

John

On Monday, September 9, 2024 at 06:25:38 PM EDT, W0LEV <davearea51a@...> wrote:


You've done about the best you can.? It's nearly a copy of my tuned loop I use only occasionally during lightning season.? The 450-foot long doublet has in the past supported a big thick blue spark up to and including 4 to 5 inches.? It is always disconnected when not in use.

Dave - W?LEV

Virus-free.


On Mon, Sep 9, 2024 at 9:57?PM Earl Parker II via <eparkerii=[email protected]> wrote:
Mostly by dumb luck I've managed to build a SW loop that seems to work well.? It's made of 1/2" OD copper tubing, about 34" across, with a 10" x 7 1/2" coupling loop made from 8 AWG copper wire about 1/16" (the thickness of a ty-wrap) from the main loop.? The coupling loop is connected to a dual banana female socket with banana connectors.? On the other end a 15' length of RG-58 goes from the BNC to the back of my radio.? The antenna has prominent nulls and is very directional.? Combining that with an old 3-section variable capacitor allows me to tune from ~4500 kHz to ~18000 kHz.
?
The only reason I went into the above is that I'm always looking for suggestions to make it even better.? If anyone sees anything I'm missing here I'd certainly appreciate hearing about it... thanks!
?
Earl



--
Dave - W?LEV
Re: Improving my shortwave loop

 

You've done about the best you can.? It's nearly a copy of my tuned loop I use only occasionally during lightning season.? The 450-foot long doublet has in the past supported a big thick blue spark up to and including 4 to 5 inches.? It is always disconnected when not in use.

Dave - W?LEV

Virus-free.


On Mon, Sep 9, 2024 at 9:57?PM Earl Parker II via <eparkerii=[email protected]> wrote:
Mostly by dumb luck I've managed to build a SW loop that seems to work well.? It's made of 1/2" OD copper tubing, about 34" across, with a 10" x 7 1/2" coupling loop made from 8 AWG copper wire about 1/16" (the thickness of a ty-wrap) from the main loop.? The coupling loop is connected to a dual banana female socket with banana connectors.? On the other end a 15' length of RG-58 goes from the BNC to the back of my radio.? The antenna has prominent nulls and is very directional.? Combining that with an old 3-section variable capacitor allows me to tune from ~4500 kHz to ~18000 kHz.
?
The only reason I went into the above is that I'm always looking for suggestions to make it even better.? If anyone sees anything I'm missing here I'd certainly appreciate hearing about it... thanks!
?
Earl



--
Dave - W?LEV
Improving my shortwave loop

 

Mostly by dumb luck I've managed to build a SW loop that seems to work well.? It's made of 1/2" OD copper tubing, about 34" across, with a 10" x 7 1/2" coupling loop made from 8 AWG copper wire about 1/16" (the thickness of a ty-wrap) from the main loop.? The coupling loop is connected to a dual banana female socket with banana connectors.? On the other end a 15' length of RG-58 goes from the BNC to the back of my radio.? The antenna has prominent nulls and is very directional.? Combining that with an old 3-section variable capacitor allows me to tune from ~4500 kHz to ~18000 kHz.
?
The only reason I went into the above is that I'm always looking for suggestions to make it even better.? If anyone sees anything I'm missing here I'd certainly appreciate hearing about it... thanks!
?
Earl
Re: Apology number two.

 

I don't think I've ever been in a group where some of the discussions go off topic, nothing wrong in that, it adds to the interest of the group.
You have nothing to apologise for for and your posts add a great deal the the group as a whole, I would urge you to stay for of our benefits.
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Paul
Re: Apology number two.

 

no apology needed except- many don't live in the U/SA and did not have a clue what MJ and growers meant.? I thought at first that you meant something to do with MFJ radio stuff.
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2 countries divided by a common language....
73
John
G8JMB
Re: comparing Wellbrook earlier ALA1530 to later ALA1530LN

 

Hey Steve!
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Was it you who was making FLG100 replacements? If so, let me know the spec's and price per module.
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How are you doing there in sunny, hot Arizona? We visited AZ in April the first time in 6 years. Still miss the Prescott area.....
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Thanks!
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Dave Aichelman? ? ?N7NZH? ? ?Grants Pass, Oregon
Re: Apology number two.

 

Add me to the list of those who hope you'll stay.? A portion of that particular post may have wandered a bit into the realm of "unusual", but certainly nothing that was out-of-bounds or requiring an apology.
Re: Apology number two.

 

Don't know why anyone made such a fuss over your initial post. RFI is an issue most of us face, no apology needed. Can't have any deviation from the same recycled subjects and seller promotions I guess.
Now I'm gonna have to go back and see what happened. I just glossed at the subject line, because, MJ, RFI, loops... Yeah, 1:1:1, and hand-in-hand. Thought noting at all about it, planned to catch up later, see if there has been any major advancements, like someone starting to think about maybe doing something before the next big bang.

Having chased RFI for decades, RFI, loop antennas, and the MAJOR issue with growing sites, how they are identified, and the extreme involvement of the ARRL, FCC, and local law enforcement makes MJ pretty much synonymous with RFI, and the equipment to locate it, or, not prevent it, but allow one to still function to an extent when in the presence of it- loop antennas.

Almost equally bad, if not more so, as it's rapidly overtaking growers for complete obliteration of anything RF related, solar.

Kurt
Re: Apology number two.

 

Don't know why anyone made such a fuss over your initial post. RFI is an issue most of us face, no apology needed. Can't have any deviation from the same recycled subjects and seller promotions I guess.
Re: Apology number two.

 

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Let this ¡®blow over¡¯! ?No more responses to it. ? ?Move on.?
Back to antennas.?
??


On Sep 6, 2024, at 11:23?AM, rfsam <1rfsam@...> wrote:

?Hi,
Please don't leave this group. I think others are overreacting to your
initial post. Don't feel to bad about it.
Regards,
Simon
Re: Apology number two.

 

Hi,
Please don't leave this group. I think others are overreacting to your
initial post. Don't feel to bad about it.
Regards,
Simon
Re: Apology number two.

 

Hi Terrence,
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It's your choice, but don't feel too bad, some folks are just too sensitive about stuff that they consider to be off-topic, or may occasionally be misjudged.
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It's just human nature, and I've inadvertently offended folks when that was not my intention. I like to push boundaries, test theories, and stop myths being propagated ad infinitum. As a result, I've been banned from many forums for not towing the party line, or supporting the other fanboys.
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Social media has allowed tribes to coalesce, without their beliefs being challenged, this is dangerous and does not promote rational discussion. I also like threads that occasionally drift off-topic, as sometimes you learn new things, or view existing stuff from a different perspective.
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The world would be very boring if we all conformed to an "acceptable" template, we need a mix of voices and experiences to remain a (almost) balanced society.
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I wish you well in your endeavours.
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Regards,
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Martin
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On Fri, Sep 6, 2024 at 10:23 AM, wn4isx wrote:

Good luck to group members and, to those offended by my eterna-post, I'm sorry
Apology number two.

wn4isx
 

Given my off topic thread won't die, it's clear I'm not up to be a moderator on this group.

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Meaning well isn't enough in life and I demonstrated an atrocious failure in judgment by starting the eterna-thread, a failure of judgment that demonstrates I'm not suited to be a moderator.

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I hope the remaining moderators can continue to act as weed killers and kill each and every post regarding MJ growhouses.

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I've enjoyed being a member of this group, learned a lot, I'd like to thank Martin for confirming a goniometer is less then optimal for electronically steering the aim point of two cross phased loops and I'd like to thank Everett N4CY for offering high performance loop at an extremely reasonable price.

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This would turn into something the length of War and Peace if I tried to thank everyone who has helped me understand the subtleties of loop antennas, so a bit thank you to the entire group.

?

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I've learned more about loops in the few years I was a member of the Loop Antennas IO Group, but I believe it is time for me to leave the group.

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Good luck to group members and, to those offended by my eterna-post, I'm sorry. Accepting responsibility means accepting rational outcomes.

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