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Re: ELF and VLF loop antennas
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?
73
& GUD DX,
Thomas F. Giella, W4HM
Lakeland, FL,
USA
https://www.facebook.com/thomasfranklingiellaw4hm
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web-based small transmitting loop calculator
Hi, all.
I've been studying transmitting loop antennas, and thought I'd have some fun combining that with learning how to put an application on the web.
The result (current version) is here:
It's different than some of the other apps out there, in that it allows easy side-by-side and graphic comparison of the projected performance of different designs.
Also, there is a link at the bottom to view the mathematics behind it.
Any comments on use, suggested additions, corrections, bug reports are very welcome.? I hope to make this a "living application" and expand the capabilities, accuracy, etc. over time.
Thanks and 73.
Dan - K3GMQ
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Re: ELF and VLF loop antennas
Thanks Phil for the leads. I’ll check them out. ? BR, Randy ?
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From: [email protected] < [email protected]> On Behalf Of Phil EVG Sent: Wednesday, May 6, 2020 9:34 PM To: [email protected]Cc: radiojayallen <radiojayallen@...> Subject: Re: [loopantennas] ELF and VLF loop antennas ? ?? Loops from A to Z Medium Wace?Circle? ? hi? ? ? also try ultralightdx?group via radiojallen?for Ferrite Sleeve Antennas ? On Wed, May 6, 2020 at 2:23 PM Randy Rich <qqq@...> wrote: Hello, I’m looking for ELF (800 – 1500 Hz) and VLF (20kHz to 40kHz) commercial receive loop antennas. Thought I’d ping the group for any recommended vendors to look into. ? General specs: Receive only 4ft x 4ft, or smaller. Square or circular is fine Active (with preamp) preferred E-field shielded preferred, but not absolutely necessary Mounting: optional ? Anyone have any vendor recommendations? ? Thanks. ? Best Regards, Randy ?
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Re: ELF and VLF loop antennas
Steve R, Yes. I am in the US, and I did already look at LF Engineering. Thanks for the lead, though. ? BR, Randy ?
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From: [email protected] < [email protected]> On Behalf Of Steve Ratzlaff Sent: Wednesday, May 6, 2020 9:28 PM To: [email protected]Subject: Re: [loopantennas] ELF and VLF loop antennas ? Hi Randy, I assume you're in North America. Try looking at LF Engineering.? 73, Steve On 5/6/2020 10:45 AM, Randy Rich wrote: Hello, I’m looking for ELF (800 – 1500 Hz) and VLF (20kHz to 40kHz) commercial receive loop antennas. Thought I’d ping the group for any recommended vendors to look into. ? General specs: Receive only 4ft x 4ft, or smaller. Square or circular is fine Active (with preamp) preferred E-field shielded preferred, but not absolutely necessary Mounting: optional ? Anyone have any vendor recommendations? ? Thanks. ? Best Regards, Randy ?
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Re: ELF and VLF loop antennas
??
??
??
Loops from A to Z Medium Wace?Circle?
hi? ? ??
? ??
also try ultralightdx?group via radiojallen?for Ferrite Sleeve Antennas
??
On Wed, May 6, 2020 at 2:23 PM Randy Rich < qqq@...> wrote: Hello, I’m looking for ELF (800 – 1500 Hz) and VLF (20kHz to 40kHz) commercial receive loop antennas. Thought I’d ping the group for any recommended vendors to look into. ? General specs: Receive only 4ft x 4ft, or smaller. Square or circular is fine Active (with preamp) preferred E-field shielded preferred, but not absolutely necessary Mounting: optional ? Anyone have any vendor recommendations? ? Thanks. ? Best Regards, Randy ?
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Re: ELF and VLF loop antennas
Hi Randy,
I assume you're in North America. Try looking at LF Engineering.?
73,
Steve
On 5/6/2020 10:45 AM, Randy Rich wrote:
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Show quoted text
Hello,
I’m looking for ELF (800 – 1500 Hz) and VLF
(20kHz to 40kHz) commercial receive loop antennas. Thought I’d
ping the group for any recommended vendors to look into.
?
General specs:
Receive only
4ft x 4ft, or smaller. Square or circular
is fine
Active (with preamp) preferred
E-field shielded preferred, but not
absolutely necessary
Mounting: optional
?
Anyone have any vendor recommendations?
?
Thanks.
?
Best Regards,
Randy
?
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Re: ELF and VLF loop antennas
hi? ? ??
? ??
also try ultralightdx?group via radiojallen?for Ferrite Sleeve Antennas
??
On Wed, May 6, 2020 at 2:23 PM Randy Rich < qqq@...> wrote: Hello, I’m looking for ELF (800 – 1500 Hz) and VLF (20kHz to 40kHz) commercial receive loop antennas. Thought I’d ping the group for any recommended vendors to look into. ? General specs: Receive only 4ft x 4ft, or smaller. Square or circular is fine Active (with preamp) preferred E-field shielded preferred, but not absolutely necessary Mounting: optional ? Anyone have any vendor recommendations? ? Thanks. ? Best Regards, Randy ?
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ELF and VLF loop antennas
Hello, I’m looking for ELF (800 – 1500 Hz) and VLF (20kHz to 40kHz) commercial receive loop antennas. Thought I’d ping the group for any recommended vendors to look into. ? General specs: Receive only 4ft x 4ft, or smaller. Square or circular is fine Active (with preamp) preferred E-field shielded preferred, but not absolutely necessary Mounting: optional ? Anyone have any vendor recommendations? ? Thanks. ? Best Regards, Randy ?
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Array Solution VNA 2180 for sale
If anyone is interested I have an Array Solutions VNA 2180 for sale. Please contact me of list if interested. These are very hard to find on the used market.
Everettsharp (at) aol com
Everett N4CY
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Re: Optimal height Antenna Loop of 39”
Normally it's around 2-3 lengths of the diameter off the ground. More than that can be used if that keeps it clear of grabby hands and pets. So I would say around 10 to 20 feet should be more than enough to avoid signal loss to the ground.?
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Optimal height Antenna Loop of 39”
Hello,
I am carrying out a new installation, of a new Amplified Loop Antenna of 39" diameter.
It is intended only for reception, it is broadband, with 50 KHz to 30 MHz coverage.
What would be the ideal height for this 39" Loop?
Thank you for your future answers
Best regards
73 Bernard
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To everyone: Please do not respond to spam, and do NOT mark as spam
Hello from your friendly neighborhood moderator. If you see spam here, or something you think feel is spam or so far off topic that it does not belong here, please email me at [email protected]?and include a link to the message on the website. Please do NOT mark as spam, especially don't mark it as spam in your email program. Due to the measures taken by many/most ISPs, groups,io will boot you from any group that you mark as spam. Even if your email program puts it in your spam folder without any action by you, if you allow it to delete it without marking it "not spam", 开云体育 will boot you from the group. No actions by me. It is not my choice that such a nuclear option be used. However, so many people sign up for a list then either forget the did, or decide they want off but somehow find it "easier" to start marking the messages as spam... or lazily allow their email program or provider to mark as spam and don't bother correcting it. Also, while we're talking about this sort of thing, I'm not your momma. If you want one of your own messages deleted, if you want to stop following a topic, if you want to change your email preferences in some way, please do so yourself. 99.9% of you seem to be self-sufficient, but I moderate a couple dozen groups with tens of thousands of members. Thank you, and stay healthy. -- Steve Greenfield AE7HD
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I just finished building 6 Improved WellGood Loop amplifiers using SMD 2SC5551 transistors, 4 LZ1AQ Loop amplifiers and 2 Modified M0AYF loop amps with SMD 2SC5551 transistors.
If anyone is interested in buying one you can contact me off list at everettsharp (at) aol? com
Everett N4CY
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Re: Tuned small active HF loops
You might look up the published work by Dave Lauder the RSGB EMC expert. He built a series of 3 tuned loops including and a micro-controller tuned version for Ofcom DSL noise measurements. The real issue was that very? expensive EMC loops could not detect and measure the noise pollution because they were? essentially deaf or the pre-amps had a very high noise floor. Dave developed these loops and you would save yourself a lot of design effort looking at his published designs. There are not many loops that can receive signal that sit down in the -20dbub to -30dbuv?? levels. The Wellbrook was assessed?? and used by the RSGB however it has no calibration data and is not of a shielded design? that meets CISPR requirements. I understand that its a hobby antenna. I doubt that there will ever be a shielded design because of the capacitance problems in the shielded design. Its incredible that people like CISPR develop standards that cant even measure what they are supposed to conform to? because their antenna designs and standards are so inadequate.
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Re: EME234 HF Active Magnetic Loop Description:
I have built 2 of these loops. The design is based on the LZ1AQ design.
They work ok and the price is good.
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Re: Most efficient Loop?
You might also want to look at the new MFJ Loop? antenna. MFJ1888. Its supposed to be a high dynamic range loop? with high performance. Its a total redesign. I have seen the Ads in QST but there is not much details on the web as yet.
I own a Wellbrook? as well as Datong? Active Dipole and Cross country Wireless dipoles. the dipoles suffer from broadcast overload but for weak signal SSB reception? I prefer them. Unfortunately there is not a modern active HF dipole available. Well there is from R&S? but they cost? 50,000 dollars. Look for a OLD Datong Dipole if you can.
Your currency is not that great so either way its going to cost you a small fortune. I have the MiniKits versions of the LZ1AQ loop and that works very well. I would start off with this option If I was you to see if the concept works for you. In most cases I find that say something like short 20 meter dipole or any short dipole works just as well as my active loops when I have noise issues.? I live in the countryside by now I am plagued by LED floodlight noise and even plasma TV's that can be heard 1km away. If i orientate the dipole well i can hear hear S1 7mhz ham stations all around the world which can be challenge on any loop even the Wellbrook.??
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Looking for Lowdown Article
Anybody keep old issues of Lowdown that could scan this article into the Files section:
"Analysis & Design of Broadband Low Frequency Loops," Lowdown, April and May 1985
Saw it referenced in a Lloyd Butler, VK5BR, article on VLF loops
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Re: YouLoop As A Folded Dipole For VHF ?
When working with an SDR, the first thing you must consider is how to isolate the antenna from your computer. If the Youloop had nothing else but that nice binocular core BalUn, it would be more than enough. You could put a couple of alligator clip-leads on it and it would sound good. The reason is that your computer is a significant source of very local RF noise. Isolating the antenna from that noise source with that BalUn is what makes the most difference.?
Don't get me wrong, the nulls a small loop has on MW and HF are very useful. But the biggest improvement in S/N for ANY band is the isolation of the antenna and coax system from the computer and its Gawdawful switching power supply.?
73,?
Jake Brodsky, AB3A
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Re: Big ferrite loopstick issue
You might have a bad capacitor, like when you have a dirty potentiometer.
Can you check the capacitor with a meter??
Carlos VK1EA
On Wednesday, April 29, 2020, Tom Seeger < thomas.b.seeger@...> wrote: Sorry. I thought you were talking about a varicap diode (varactor) to tune the tank. You are talking about a variable capacitor. My bad.
Tom
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Re: YouLoop As A Folded Dipole For VHF ?
I have? Youloop 5 feet by 3 feet, to fit around an internal
window frame, it works well on VLF to HF and as well, if not
better, than simple wire dipoles on FM and DAB (225MHz)
frequencies. Unlike the wire dipoles, it is wideband. If you were
making your own Youloop, two lengths of coax about half a
wavelength long, joined with the crossover connection would give
the correct dimensions for a folded dipole, if made into an
elongated shape. I think that would give my loop a resonant
frequency around 60MHz.
Regards,
Ian Brooks, Verwood, Dorset, UK.
On 28/04/2020 16:24, rmrrgs wrote:
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Hello,
Just received the AirSpy YouLoop ant.
Question, please:? It say it is usable in the vhf range as a
folded dipole.
So, if I want to use it at around 118 MHz AM,do I have to distort
the present circular
shape into something resembling a rectangle for the folded
dipole/vhf arrangement ?
If so, But I leave it circular, would it work "at all" in the VHF
?
Thanks,
Bob
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Everett N4CY
Steven Greenfield AE7HD
Ian Brooks