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Locked
Re: Mag-Loop Antenna question.
This is mostly from my gut feeling and reasoning, but I present an opposing view.? I would tend toward a wider gap rather than narrower.? But there may be a lot of leeway. The ends make a small capacitor, which limits the minimum total capacitance and the maximum frequency to which it can be tuned.? If you make the ends very close together, you increase that capacitance and lower the max. frequency and the total tunable frequency range. For a transmitting antenna, the ends have VERY high voltage so there is a voltage gradient across that gap.? Too close, and it will arc. 25mm is an inch.? It might have come from an American who used an inch as a round number, which got translated to Metric.? What's the breakdown voltage of air?? And how large a peak voltage do you have there? Performance-wise as an antenna, I suspect the gap doesn't make much difference.? The high current in the loop follows around the loop and into the wires or straps that tap off to go to the tuning capacitor.? Any loop material beyond those points doesn't carry the loop's high current; they just make a capacitor, in parallel with your tuning capacitor.? They probably do not radiate anything significant. Andy |
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Re: Mag-Loop Antenna question.
Somebody with more knowledge please correct me... I would say that if the gap is significantly less than the overall diameter it shouldn't matter. I say that assuming that the tuning capacitor is much larger than the distributed capacitance of the loop itself and that the inductance of the loop will not deviate greatly from the design model if the gap is small compared to the overall loop area. So if your loop diameter is 12 inches, you should probably not have a gap more than about 1 inch, but I would think with a 6 foot diameter you could get away with two inches. I doubt that the relationship is linear, it may even be related to the radiator thickness; so I would attempt to make the gap small. However, I know of several loop designs where the main radiator is separated by several inches and wires are connected to the tuning capacitor. The actual gap may be small but the large loop radiator has larger physical gap. Sorry this is not more definitive. If anybody can provide a link to the relevant equations that would be very helpful. 73s, Bob Cavanaugh - AG6YK On Monday, February 9, 2015 2:23 PM, "phil blast dj_philonline@... [loopantennas]" wrote:
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Ive only made 3 and followed the old one inch gap rule on the last one which is 25mm and on an ali bicycle wheel and it works great, did make one with pipe and plates soldered on the gap which acted as the capacitor so I guess too close will increase capacitance, on the first one the gap was the width of the single variable capacitor I used which was directly connected to the loop and was about 45 to 50mm and that worked fine so more seems OK. Just my findings others may differ? whatever you do once its working you will enjoy it that is guaranteed. 73 Phil M6MRP On Monday, 9 February 2015, 20:19, "nick.nickrumple@... [loopantennas]" wrote:
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Hi All.....I have a question about a 1 meter, capacitor tuned mag-loop that I am building. So far, after a few trial sessions, it works very well. But, I have been reading many online articles from people who build these antennas. While reading these articles, I noticed that many people made the gap at the top of the antenna (where the tuning capacitor connects across) seem like a very big deal. Many of them quoted figures like 25 mm gap. My question is, does the size of the gap make a difference in the performance of the antenna? Thanks for any help you can give. Nick Rumple Kannapolis, North Carolina |
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Re: Mag-Loop Antenna question.
phil blast
Ive only made 3 and followed the old one inch gap rule on the last one which is 25mm and on an ali bicycle wheel and it works great, did make one with pipe and plates soldered on the gap which acted as the capacitor so I guess too close will increase capacitance, on the first one the gap was the width of the single variable capacitor I used which was directly connected to the loop and was about 45 to 50mm and that worked fine so more seems OK. Just my findings others may differ? whatever you do once its working you will enjoy it that is guaranteed. 73 Phil M6MRP On Monday, 9 February 2015, 20:19, "nick.nickrumple@... [loopantennas]" wrote:
?
Hi All.....I have a question about a 1 meter, capacitor tuned mag-loop that I am building. So far, after a few trial sessions, it works very well. But, I have been reading many online articles from people who build these antennas. While reading these articles, I noticed that many people made the gap at the top of the antenna (where the tuning capacitor connects across) seem like a very big deal. Many of them quoted figures like 25 mm gap. My question is, does the size of the gap make a difference in the performance of the antenna? Thanks for any help you can give. Nick Rumple Kannapolis, North Carolina |
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Mag-Loop Antenna question.
Hi All.....I have a question about a 1 meter, capacitor tuned mag-loop that I am building. So far, after a few trial sessions, it works very well. But, I have been reading many online articles from people who build these antennas. While reading these articles, I noticed that many people made the gap at the top of the antenna (where the tuning capacitor connects across) seem like a very big deal. Many of them quoted figures like 25 mm gap. My question is, does the size of the gap make a difference in the performance of the antenna? Thanks for any help you can give.
Nick Rumple Kannapolis, North Carolina |
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File - UploadingFilesLinksPhotos.txt
If you have a link relevant to the group, please post it in the Links section. If you just put it in a message, it will get lost in the shuffle after a few days. The coverage of the list is pretty broad.
All members can upload Links, Files, and Photos. A few guidelines: Try to place them in the proper folder, if it exists. If not, you can either just put it in the root folder and eventually I'll move it into the proper place, or create a folder. When creating a folder or uploading a file or photo, please don't use spaces or punctuation. You can either use caps for the first letter of each word, or use underscore as a space. Like this: "4x8Loop" or "4x8_loop" or "Steves_4x8_Loop" Not like this: "Steve's 4 x 8 Loop." That goes for Folder names and File names. A special note about the Photos section: Please crop in to the important parts. For photos, JPG saves smaller and looks better, for line drawings GIF is smaller and looks better. Please do not use TIFF/TIF or BMP files, the file size is way too big and I may delete without notice. Feel free to ask if you need help figuring out how to crop and resample. Irfanview is a fairly easy to use program that loads just about any file, you can crop and resample from there: Or for more complex stuff, another free program is GIMP: Attachments are now allowed, but please use judiciously. Rather than going out with the messages, they will be stored on the list but you'll get a link with the message. A last note: if you see something in any folder or in the messages that looks like spam or simply inappropriate, don't post on the list- email me directly and tell me about it and I'll take care of it with a minimum of fuss. loopantennas-owner@... Thanks, Steve Greenfield |
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File - Links.txt
Active AM Antenna With Twin Coil Ferrite by C. Crane Co.
JLKolb?s antenna links including the KRS AA-1 Active Antenna schematic, antenna preamplfiers, center-tapped loops, and a dual gate FET preselector. Directional Terminated MW/LW Loop by WellBroook (UK) K9AY is the Remote Controlled Variable Termination; Provides a Cardioid Reception Pattern with up to 30dB Gain Front-to-Back; Uses Two Delta Loops. Kiwa - High Performance MW Air-Core Loop Antenna High Performance MW Air-Core Loop Antenna by KIWA Palomar Engineers Loop Antennas LW-MW-SW2 Palomar's Loop Antenna gives superb performance on the AM medium-wave broadcast band. The loop rotates and tilts to give deep nulls so you can eliminate local interference. It also allows you to null out a station and listen to another one on the same frequency. The Quantum loop antennas, now V2.0 Terk AM loop at Amazon.com Here is a place you can buy yourself a TERK AM loop antenna, even some other stuff that is kind of off topic to talk about. 73 WL1030 by the late Maartenhagg. Plans placed on this website by his friends in his honor. C Crane Company They sell the Justice AM Loop Antenna, Select A Tenna, Terk AM 1000 Kiwa Electronics Kwia makes the best products for you and your radio equipment, and also improves things that needed improvement a long time ago. Stormwise Ferrite Rods Get some huge ferrite rods and a converter to go along with its, heck it even comes with project book. Universal Radio Company They sell all sorts of loops big and small for LW/MW/SW and VLF also 10 kHz to 15 MHz ALA-1530 Find the best UK LF/MF antenna here. AOR This is the site that sells the AOR loop Kiwa Electronics The maker of the air core loop antenna and other useful items that you may want on your wish list. LF Engineering Company A group of engineers, who make products for VLF/LF listening even ELF loops! Select A Tenna by Intensitronics Corp The maker of the select A tenna, a great AM loop antenna that is a little bigger than the terk discontinued Terk Technolegies The maker of the best sold AM and I use also called the AM-1000 AM loop antenna, there is also technical information on how it works. Torus Tuner Loop Company A very specially made loop that is almost as big as a hula hoop discontinued GRAHN (Germany) Specialized Loop Antennas for MW and SW Reception Contributed by radiohighfreq Grahn offers both Ferrite Rod Antennas and Shielded Loop Antennas. Translated from the Gremany Language Webpages here is the "Grahn Specialized Loop Antennas for MW and SW Reception" ULR Address: Use the Google Translate a web Page Tool to convert these webpages to English. When considering AM Loop Antennas . . . - - - It all comes down to Time? & Money? How much Time? Are you going to be 'using' the Loop Antenna for DXing or simply for "Better" AM Radio Reception (Sports/Talk Radio Loop). How Much Money? Are you willing to spend for a Loop Antenna to get the kind of better reception you want. TBL: Time and Money translates to the AM Loop Antenna's Value to You. The average radio listener (97%), who wants better AM Radio Reception, can spend $100 or less and get an AM Loop Antenna that meets their needs. Here is a brief list of the more common AM Loop Antennas for $100 or less. * Twin Coil Ferrite AM Loop Antenna (Active) - - - * Torus Tuner 27" Loop Antenna (Passive) - - - discontinued * Select-A-Tenna Model #541M (Passive) - - - discontinued * Terk AM Advantage Loop Antenna (Passive) - - - * RadioShack AM Loop Antanna # 15-1853 (Passive) - - - Discontinued (Find 'used' on eBay) * MTM Scientific AM Radio Loop Antenna (Passive) * - - - Starter Kit, Deluxe Kit or Finished Antenna! * * * Home made 'Box' AM Loop Antennas - Usually 20" to 24" in size - - Generally a simple Passive antenna - - - Can be made Active with an add-on amplifier #1. * Justice AM Loop Antenna (Active) - - - discontinued#2. * Torus Tuner 27" Loop Antenna (Passive) - - - website gone#3. * Select-A-Tenna Model #541M (Passive) - - - website gone#4. * Terk AM Advantage Loop Antenna (Passive) - - -#5. * RadioShack AM Loop Antanna # 15-1853 (Passive) - - - Discontinued (Find 'used' on eBay) #1.a. Kiwa MW Air Loop Antenna #1.b. Quantum Loop Antennas . . . #3. Palomar Loop Antenna Basic Wire Back Yard Loop Antennas Full-wave loops are very popular antennas. They are especially useful on 80 and 40 meters where they perform well at modest heights. These are closed loops that are one full wavelength long. Horizontal loops may be fed at any convenient spot. For best performance, make your horizontal loop into a square, especially if it is to be used on several bands. K9AY: How to Build the K9AY Loop Receiving Antenna AY Technologies Antennas by K9AY. Excellent Antenna for Medium Wave Frequency DXing. Six Foot Square by Six Turn Loop Antenna New Mid-Size Loop Antenna by Graham Maynard with Matching Balanced Amplifier: Frequency Range 50KHz - 5000KHz. Ten Foot Receiveing Loop for Low-Frequency DXing A Page out of VE7SL's Note Book. This 10 Ft. Air-Core Receiving Loop was originally designed and constructed for NDB DXing and now is used for LOWFER DX work. Dave's HomeMade Loop Antennas This is the loop antenna my dad built in 1958. Although I was only 8 years old at the time, I knew what this was for and how it worked. WebSite/Pages produced by Dave Schmarder Page Contributed by radiohighfreq 4 Foot Box loop antenna Heres a 4 foot loop project by Bruce ATL-3 Loop Antenna by Graham Maynard (UK) Loop & Amp Project: ATL-3 Loop Windings are in the Shape of a Five 26" Sided Spiral Alt-Azimuth Wooden "HOOP LOOP" Antenna by Linus The Great Pumpkin" Speaks on "How To Make" a Loop Antenna from a Wooden Embroidery Hoop. Read the Exciting Saga of his journey in to the Kingdom of Hooppy-Looppy-Dom presented by RadioIntel.Com. DXers Tool Box - DIY - Tuned Loop Antenna The DXers Tool Box "How To Build" a Tuned Loop Antenna = How can you vastly improve your Medium Wave reception? The antenna consists of an LC (tuning) circuit formed by the air-core loop and a tuning capacitor. Embrodary Loops While these loop are for crafts, they can be a craft of art for improved AM radio reception! Hard Core DXing Here's what nordic dx has to offer in their discription of loops in this website K5DKZ - Three Foot Box Loop Antenna Kit Complete Parts and Plans for a 3 Ft Box Loop Antenna "Kit" ~$85+SH KIT -by- MTM Scientific, Inc. -for- AM Radio DX Loop Antenna KIT =//= Designed to Build an AM/MW Radio DX Loop Antenna =//= Offered by MTM Scientific =//= Deluxe Loop Antenna Kit: Includes ALL the Hardware for Building this AM/MW Radio DX Loop Antenna. Long LoopStick Antenna for MW DXing Wound on a Three (3) Foot Length of PVC pipe, the "Long LoopStick Antenna" was an experiment to try to improve AM radio reception without using a long wire or ground. TL Loop Receiving Antenna 10 KHz - 30 MHz The principle of operation is that an rf voltage appears across the terminals of a loop when it is placed in an electromagnetic field. The voltage is proportional to frequency for a given field strength and so at Very Low Frequencies the voltage is very small and requires greater amplification but it is not quite as simple as that. The new TL Loop uses a unique feedback system to optimise the amplification/noise factor over a much wider range than has been possible hitherto. W2BRI Xmit Loops Contributed by n3hkn Ham Radio xmitting loops. Detailed plans and reports from Hams experiences. Typical cost is $50 for pipe, capacitor, motor. "AM Loop Antenna Calculator" - by Bruce Carter Here is a Great Tool for those Loop Antenna => "What Ifs...." "Loop Antennas 101" Read This First Minnesota DX Club's Loop Antenna's web page that is a 'Must Read' =Says It All= A Starting Point Class 101- - - TOPICS: Principles of the Loop Antenna - What is a Loop and Why Use It - Construction Principles - What Can I Use a Loop For - Loops Another Look - Pictures of Home Built PVC loops - Loop Links * NEW => 2002 AM Loop Antenna Construction "Tips" by Bruce Carter Introduction / Why Another Loop Antenna Page? / Mathematics of Rectangular Loop Antennas / Construction Articles / Loop Antenna (and Related) Links Loop Antennas at Hard Core DX TABLE: Number of Turns -v- Size of Loop in the Middle of this webpage. Loops and Rods =&= The Ferrite Rod Antenna Theory / Formulas / Drawings = The use of a small Magnetic Loop as an antenna. The ferrite has the effect of intensifying the magnetic field inside the loop. Modify the common AM Radio Loop Antenna Hard-Core DX & Nordic DX = Topics: Install Larger Ferrite Rod - Fix External Antenna -Add a Long Wire - Or a Loop - Construct it - Connect it - Add an Amplifier. Presented by Bruce Carter Sensitivity of Multi Turn Receiving Loops LWCA - Multi turn wire loops are often used as low frequency receiving antennas. Basic electromagnetic theory is developed here as it relates to electrically small multi-turn loops at low frequencies. - Presented by William E. Payne, N4YWK Using the Small Loop Antenna by Joe Carr DXing.Com presents Joe Carr's Radio Tech Notes: Eight Page PDF Document provided by Universal-Radio.Com How to Get Better AM Radio Reception Features Loop Antennas and much more. The Antenna is 90% of Your Radio. Still Need More Signal? Try a Better Antenna. Introduction to Broadcast Band AM/BCB/MW DXing The International Radio Club of America (IRCA) WebPages ** Radio-Antenna-PRO ** H.Hertz-Forum Remember you may need some Russian Text software for this groupThe international forum for radioengineers, scientists and hams. All about radioelectronics, radiocommunications, radiophysics, electrodynamics. About 250 members from 20 countries. In Russian language. Very active. Lot of interesting researches and discussions. Radio DXing with The Interference Problem This is great for that annoying problem you have with your loop antenna, and you may think its the loop, think again it could be that messed up street light, next doors dimmer switch, and other something else you can't probably solve with just a loop antenna. "3805er" 80-Meter balanced coax loop Small shielded rx only loop for 80 meters Magnetic Loop Antennas Receiving - by W8JI This WebPage's Topic Are: - Small Receiving Loops - Loop Antenna Fields - Dipole Antenna Fields - Radiation - Loop Shielding and Balance - by W8JI Radiation and Fields (Magnetic Loop Antennas) - by W8JI This WebPage's Topic Are: - Electric Field - Magnetic Field - ElectroMagnetic Field - Near the Antenna - Losses - Near Field - Fresnel Zone - Farfield - Summary - by W8JI Shielded-Loop Receiving Antenna by N5FC Shielded-Loop antennas have some nice properties that make them desirable as portable receiving antennas. Antique Electronic Supply A sorts of older variable tuning capacitors for your loop antenna that needs one bad. Fair Radio Sales A wide variety of electronic components, radios, and variable capacitors for your loop antenna Ocean State Electronics Rhode Island's best selection for a wide variety of the best tuning capacitors for reasonable price, tell them that electronicdx (Adam Ebel) sent you. The Crystal Set Society Here are some capacitor available from a club that devotes to Crystal Set Radio The Surplus Sales of Nebraska This surplus store based in the state of Nebraska, has the one you might need, but they have minumim order policy Dan Small Parts and Kits Dan's wide selection from Canada. American Science and Surplus A big spool of wire here just about for AM DigiKey.com For ribbon cable and other sorts of wire. Femco Magnet Wire Femco Magnet Wire is a joint venture company that has been supplying round insulated copper magnet (winding) wire to the transplant market since 1988. Litz-Wire,com Welcome to Litz-Wire.com! MCM electronics They do sell wire and magnet wire here MWS Industries A place for all sorts of wire for business and industry Magnet Wire from Radio Shack This is what I use often Mouser Electronics Mouser has the biggest spools here for a great price, that makes sense Ocean State Electronics magnet wire at a good price WIRE "Flex-Weave" Antenna Wire "Flex-Weave" is a hybrid aerial wire that consists of 168 strands of woven #36 solid copper wires that provide high strength and extreme flexibility. The most popular version of "Flex-Weave" is the 'equivalent' of #14 AWG wire size. It can be 'used' for unsupported spans up to 200 ft (100-150 ft in areas with high ice and wind loading). WIRE "QuietFlex" Antenna Wire by Antennas & More: Insulated, Strong, Flexible and Durable "QuietFlex" Antenna Wire by Antennas & More: "QuietFlex" #14 AWG Wire has more than 41 Strands tightly twisted together under its Flexible Insulation making it both Strong, Flexible and Durable. Scanning, Ham Radio and Public Safety Resources - Links to the various webpages with resources for the Ham Radio Operator and Scanning Enthusiast. Resources such as; Monitoring Police and Fire Communications, What Antennas to use, Secret Scanner Frequencies, Radio Programming Software, Radio Mods and Operating Tips, Professional resources for Public Safety Management, Guidance and Self-Help. Amidon Ferrite rods, bars, plates, and tubes. Bytemark Ferrite rods, bars, plates, and tubes. |
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Re: Schematic wanted to repair C Crane antenna
Here are the circuit and block diagrams from the patent (attached).
toggle quoted message
Show quoted text
I own a Twin Coil Ferrite Antenna but it does not work well for me in my situation. I ended up putting up a SW/HF active antenna (RYOAA (eBay)) outside and running the coax inside to a Drake SPR-4 and also a Drake 1260/PRN1000 connected to the stereo. Don KPC6NDB Upland, CA 34.10 -117.63 1250ft FRG-100B FunCube Dongle Pro+ ICF2010 Perseusx3 WR-G31DDC R70 R71A w/250Hz R75x2 w/250Hz SDR-IQ SPR-4 SSR-1 SR-AF & LPF DSP599zx MFJ-784B HD-1418 AF-1 MSB-1 PA0RDT Mini-Whipx2 @ 25ft RYO Active Antenna @ 25ft ALA100Lx2 Z1501F @20ft w/9ft Whip Solarcon A-99 On 29-Jan-15 13:29, tpagotie@... [loopantennas] wrote:
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Schematic wanted to repair C Crane antenna
I've got a C Crane twin loop antenna, and it doesn't work.? It would same me a lot of time if someone can point me in the direction of a schematic.? I've searched all over this forum and internet in general and not come up with anything.
thanks, tom |
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File - UploadingFilesLinksPhotos.txt
If you have a link relevant to the group, please post it in the Links section. If you just put it in a message, it will get lost in the shuffle after a few days. The coverage of the list is pretty broad.
All members can upload Links, Files, and Photos. A few guidelines: Try to place them in the proper folder, if it exists. If not, you can either just put it in the root folder and eventually I'll move it into the proper place, or create a folder. When creating a folder or uploading a file or photo, please don't use spaces or punctuation. You can either use caps for the first letter of each word, or use underscore as a space. Like this: "4x8Loop" or "4x8_loop" or "Steves_4x8_Loop" Not like this: "Steve's 4 x 8 Loop." That goes for Folder names and File names. A special note about the Photos section: Please crop in to the important parts. For photos, JPG saves smaller and looks better, for line drawings GIF is smaller and looks better. Please do not use TIFF/TIF or BMP files, the file size is way too big and I may delete without notice. Feel free to ask if you need help figuring out how to crop and resample. Irfanview is a fairly easy to use program that loads just about any file, you can crop and resample from there: Or for more complex stuff, another free program is GIMP: Attachments are now allowed, but please use judiciously. Rather than going out with the messages, they will be stored on the list but you'll get a link with the message. A last note: if you see something in any folder or in the messages that looks like spam or simply inappropriate, don't post on the list- email me directly and tell me about it and I'll take care of it with a minimum of fuss. loopantennas-owner@... Thanks, Steve Greenfield |
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File - Links.txt
Active AM Antenna With Twin Coil Ferrite by C. Crane Co.
JLKolb?s antenna links including the KRS AA-1 Active Antenna schematic, antenna preamplfiers, center-tapped loops, and a dual gate FET preselector. Directional Terminated MW/LW Loop by WellBroook (UK) K9AY is the Remote Controlled Variable Termination; Provides a Cardioid Reception Pattern with up to 30dB Gain Front-to-Back; Uses Two Delta Loops. Kiwa - High Performance MW Air-Core Loop Antenna High Performance MW Air-Core Loop Antenna by KIWA Palomar Engineers Loop Antennas LW-MW-SW2 Palomar's Loop Antenna gives superb performance on the AM medium-wave broadcast band. The loop rotates and tilts to give deep nulls so you can eliminate local interference. It also allows you to null out a station and listen to another one on the same frequency. The Quantum loop antennas, now V2.0 Terk AM loop at Amazon.com Here is a place you can buy yourself a TERK AM loop antenna, even some other stuff that is kind of off topic to talk about. 73 WL1030 by the late Maartenhagg. Plans placed on this website by his friends in his honor. C Crane Company They sell the Justice AM Loop Antenna, Select A Tenna, Terk AM 1000 Kiwa Electronics Kwia makes the best products for you and your radio equipment, and also improves things that needed improvement a long time ago. Stormwise Ferrite Rods Get some huge ferrite rods and a converter to go along with its, heck it even comes with project book. Universal Radio Company They sell all sorts of loops big and small for LW/MW/SW and VLF also 10 kHz to 15 MHz ALA-1530 Find the best UK LF/MF antenna here. AOR This is the site that sells the AOR loop Kiwa Electronics The maker of the air core loop antenna and other useful items that you may want on your wish list. LF Engineering Company A group of engineers, who make products for VLF/LF listening even ELF loops! Select A Tenna by Intensitronics Corp The maker of the select A tenna, a great AM loop antenna that is a little bigger than the terk discontinued Terk Technolegies The maker of the best sold AM and I use also called the AM-1000 AM loop antenna, there is also technical information on how it works. Torus Tuner Loop Company A very specially made loop that is almost as big as a hula hoop discontinued GRAHN (Germany) Specialized Loop Antennas for MW and SW Reception Contributed by radiohighfreq Grahn offers both Ferrite Rod Antennas and Shielded Loop Antennas. Translated from the Gremany Language Webpages here is the "Grahn Specialized Loop Antennas for MW and SW Reception" ULR Address: Use the Google Translate a web Page Tool to convert these webpages to English. When considering AM Loop Antennas . . . - - - It all comes down to Time? & Money? How much Time? Are you going to be 'using' the Loop Antenna for DXing or simply for "Better" AM Radio Reception (Sports/Talk Radio Loop). How Much Money? Are you willing to spend for a Loop Antenna to get the kind of better reception you want. TBL: Time and Money translates to the AM Loop Antenna's Value to You. The average radio listener (97%), who wants better AM Radio Reception, can spend $100 or less and get an AM Loop Antenna that meets their needs. Here is a brief list of the more common AM Loop Antennas for $100 or less. * Twin Coil Ferrite AM Loop Antenna (Active) - - - * Torus Tuner 27" Loop Antenna (Passive) - - - discontinued * Select-A-Tenna Model #541M (Passive) - - - discontinued * Terk AM Advantage Loop Antenna (Passive) - - - * RadioShack AM Loop Antanna # 15-1853 (Passive) - - - Discontinued (Find 'used' on eBay) * MTM Scientific AM Radio Loop Antenna (Passive) * - - - Starter Kit, Deluxe Kit or Finished Antenna! * * * Home made 'Box' AM Loop Antennas - Usually 20" to 24" in size - - Generally a simple Passive antenna - - - Can be made Active with an add-on amplifier #1. * Justice AM Loop Antenna (Active) - - - discontinued#2. * Torus Tuner 27" Loop Antenna (Passive) - - - website gone#3. * Select-A-Tenna Model #541M (Passive) - - - website gone#4. * Terk AM Advantage Loop Antenna (Passive) - - -#5. * RadioShack AM Loop Antanna # 15-1853 (Passive) - - - Discontinued (Find 'used' on eBay) #1.a. Kiwa MW Air Loop Antenna #1.b. Quantum Loop Antennas . . . #3. Palomar Loop Antenna Basic Wire Back Yard Loop Antennas Full-wave loops are very popular antennas. They are especially useful on 80 and 40 meters where they perform well at modest heights. These are closed loops that are one full wavelength long. Horizontal loops may be fed at any convenient spot. For best performance, make your horizontal loop into a square, especially if it is to be used on several bands. K9AY: How to Build the K9AY Loop Receiving Antenna AY Technologies Antennas by K9AY. Excellent Antenna for Medium Wave Frequency DXing. Six Foot Square by Six Turn Loop Antenna New Mid-Size Loop Antenna by Graham Maynard with Matching Balanced Amplifier: Frequency Range 50KHz - 5000KHz. Ten Foot Receiveing Loop for Low-Frequency DXing A Page out of VE7SL's Note Book. This 10 Ft. Air-Core Receiving Loop was originally designed and constructed for NDB DXing and now is used for LOWFER DX work. Dave's HomeMade Loop Antennas This is the loop antenna my dad built in 1958. Although I was only 8 years old at the time, I knew what this was for and how it worked. WebSite/Pages produced by Dave Schmarder Page Contributed by radiohighfreq 4 Foot Box loop antenna Heres a 4 foot loop project by Bruce ATL-3 Loop Antenna by Graham Maynard (UK) Loop & Amp Project: ATL-3 Loop Windings are in the Shape of a Five 26" Sided Spiral Alt-Azimuth Wooden "HOOP LOOP" Antenna by Linus The Great Pumpkin" Speaks on "How To Make" a Loop Antenna from a Wooden Embroidery Hoop. Read the Exciting Saga of his journey in to the Kingdom of Hooppy-Looppy-Dom presented by RadioIntel.Com. DXers Tool Box - DIY - Tuned Loop Antenna The DXers Tool Box "How To Build" a Tuned Loop Antenna = How can you vastly improve your Medium Wave reception? The antenna consists of an LC (tuning) circuit formed by the air-core loop and a tuning capacitor. Embrodary Loops While these loop are for crafts, they can be a craft of art for improved AM radio reception! Hard Core DXing Here's what nordic dx has to offer in their discription of loops in this website K5DKZ - Three Foot Box Loop Antenna Kit Complete Parts and Plans for a 3 Ft Box Loop Antenna "Kit" ~$85+SH KIT -by- MTM Scientific, Inc. -for- AM Radio DX Loop Antenna KIT =//= Designed to Build an AM/MW Radio DX Loop Antenna =//= Offered by MTM Scientific =//= Deluxe Loop Antenna Kit: Includes ALL the Hardware for Building this AM/MW Radio DX Loop Antenna. Long LoopStick Antenna for MW DXing Wound on a Three (3) Foot Length of PVC pipe, the "Long LoopStick Antenna" was an experiment to try to improve AM radio reception without using a long wire or ground. TL Loop Receiving Antenna 10 KHz - 30 MHz The principle of operation is that an rf voltage appears across the terminals of a loop when it is placed in an electromagnetic field. The voltage is proportional to frequency for a given field strength and so at Very Low Frequencies the voltage is very small and requires greater amplification but it is not quite as simple as that. The new TL Loop uses a unique feedback system to optimise the amplification/noise factor over a much wider range than has been possible hitherto. W2BRI Xmit Loops Contributed by n3hkn Ham Radio xmitting loops. Detailed plans and reports from Hams experiences. Typical cost is $50 for pipe, capacitor, motor. "AM Loop Antenna Calculator" - by Bruce Carter Here is a Great Tool for those Loop Antenna => "What Ifs...." "Loop Antennas 101" Read This First Minnesota DX Club's Loop Antenna's web page that is a 'Must Read' =Says It All= A Starting Point Class 101- - - TOPICS: Principles of the Loop Antenna - What is a Loop and Why Use It - Construction Principles - What Can I Use a Loop For - Loops Another Look - Pictures of Home Built PVC loops - Loop Links * NEW => 2002 AM Loop Antenna Construction "Tips" by Bruce Carter Introduction / Why Another Loop Antenna Page? / Mathematics of Rectangular Loop Antennas / Construction Articles / Loop Antenna (and Related) Links Loop Antennas at Hard Core DX TABLE: Number of Turns -v- Size of Loop in the Middle of this webpage. Loops and Rods =&= The Ferrite Rod Antenna Theory / Formulas / Drawings = The use of a small Magnetic Loop as an antenna. The ferrite has the effect of intensifying the magnetic field inside the loop. Modify the common AM Radio Loop Antenna Hard-Core DX & Nordic DX = Topics: Install Larger Ferrite Rod - Fix External Antenna -Add a Long Wire - Or a Loop - Construct it - Connect it - Add an Amplifier. Presented by Bruce Carter Sensitivity of Multi Turn Receiving Loops LWCA - Multi turn wire loops are often used as low frequency receiving antennas. Basic electromagnetic theory is developed here as it relates to electrically small multi-turn loops at low frequencies. - Presented by William E. Payne, N4YWK Using the Small Loop Antenna by Joe Carr DXing.Com presents Joe Carr's Radio Tech Notes: Eight Page PDF Document provided by Universal-Radio.Com How to Get Better AM Radio Reception Features Loop Antennas and much more. The Antenna is 90% of Your Radio. Still Need More Signal? Try a Better Antenna. Introduction to Broadcast Band AM/BCB/MW DXing The International Radio Club of America (IRCA) WebPages ** Radio-Antenna-PRO ** H.Hertz-Forum Remember you may need some Russian Text software for this groupThe international forum for radioengineers, scientists and hams. All about radioelectronics, radiocommunications, radiophysics, electrodynamics. About 250 members from 20 countries. In Russian language. Very active. Lot of interesting researches and discussions. Radio DXing with The Interference Problem This is great for that annoying problem you have with your loop antenna, and you may think its the loop, think again it could be that messed up street light, next doors dimmer switch, and other something else you can't probably solve with just a loop antenna. "3805er" 80-Meter balanced coax loop Small shielded rx only loop for 80 meters Magnetic Loop Antennas Receiving - by W8JI This WebPage's Topic Are: - Small Receiving Loops - Loop Antenna Fields - Dipole Antenna Fields - Radiation - Loop Shielding and Balance - by W8JI Radiation and Fields (Magnetic Loop Antennas) - by W8JI This WebPage's Topic Are: - Electric Field - Magnetic Field - ElectroMagnetic Field - Near the Antenna - Losses - Near Field - Fresnel Zone - Farfield - Summary - by W8JI Shielded-Loop Receiving Antenna by N5FC Shielded-Loop antennas have some nice properties that make them desirable as portable receiving antennas. Antique Electronic Supply A sorts of older variable tuning capacitors for your loop antenna that needs one bad. Fair Radio Sales A wide variety of electronic components, radios, and variable capacitors for your loop antenna Ocean State Electronics Rhode Island's best selection for a wide variety of the best tuning capacitors for reasonable price, tell them that electronicdx (Adam Ebel) sent you. The Crystal Set Society Here are some capacitor available from a club that devotes to Crystal Set Radio The Surplus Sales of Nebraska This surplus store based in the state of Nebraska, has the one you might need, but they have minumim order policy Dan Small Parts and Kits Dan's wide selection from Canada. American Science and Surplus A big spool of wire here just about for AM DigiKey.com For ribbon cable and other sorts of wire. Femco Magnet Wire Femco Magnet Wire is a joint venture company that has been supplying round insulated copper magnet (winding) wire to the transplant market since 1988. Litz-Wire,com Welcome to Litz-Wire.com! MCM electronics They do sell wire and magnet wire here MWS Industries A place for all sorts of wire for business and industry Magnet Wire from Radio Shack This is what I use often Mouser Electronics Mouser has the biggest spools here for a great price, that makes sense Ocean State Electronics magnet wire at a good price WIRE "Flex-Weave" Antenna Wire "Flex-Weave" is a hybrid aerial wire that consists of 168 strands of woven #36 solid copper wires that provide high strength and extreme flexibility. The most popular version of "Flex-Weave" is the 'equivalent' of #14 AWG wire size. It can be 'used' for unsupported spans up to 200 ft (100-150 ft in areas with high ice and wind loading). WIRE "QuietFlex" Antenna Wire by Antennas & More: Insulated, Strong, Flexible and Durable "QuietFlex" Antenna Wire by Antennas & More: "QuietFlex" #14 AWG Wire has more than 41 Strands tightly twisted together under its Flexible Insulation making it both Strong, Flexible and Durable. Scanning, Ham Radio and Public Safety Resources - Links to the various webpages with resources for the Ham Radio Operator and Scanning Enthusiast. Resources such as; Monitoring Police and Fire Communications, What Antennas to use, Secret Scanner Frequencies, Radio Programming Software, Radio Mods and Operating Tips, Professional resources for Public Safety Management, Guidance and Self-Help. Amidon Ferrite rods, bars, plates, and tubes. Bytemark Ferrite rods, bars, plates, and tubes. |
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Butterfly Capacitor Kits
Butterfly Capacitor Kitscustom made air capacitors,butterfly?capacitor parts? ?
0.04" sheet copper,brass,aluminum? |
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Re: Multiiturn loop antanna
The answer to that has already been posted.? The radiation resistance is a term to account for the power going into an antenna that is radiated rather than turned into heat.? Doubling the number of turns quadruples the inductance and reactance.? This cuts the current in half for the same power into the antenna, but it also means a matching circuit is required or must be changed.? The halved current reduces the loss in the ohmic resistance.? More power is radiated.? It won't be twice as much power since the increase is coming from the reduced ohmic losses.? But the radiation resistance will approximately double.
Rick |
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Re: Multiiturn loop antanna
It should be available somewhere in the US under FOI if the data given
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is correct. It's not on the Internet Archive site which is strange as they have much of US Defense stuff. Cheers, Will. ZL1TAO On 27/12/14 17:14, Don Sanders w4bws1@... [loopantennas] wrote:
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Re: Multiiturn loop antanna
Yes, it looks like a good report but I could not find a download button. My Japanese is worse than my Greek which is zero. Dr. Don HC4/W4BWS On Fri, Dec 26, 2014 at 11:01 PM, qrp.gaijin@... [loopantennas] <loopantennas@...> wrote:
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Re: Multiiturn loop antanna
In loopantennas@..., <ai.egrps@...> wrote : > Then I suppose the question would be, what does the radiation > resistance do when using two or more turns in series? The formula for the radiation resistance of a multi-turn loop is given on p. 11 of the document I posted earlier. The radiation resistance increases with the square of the number of turns. As for the loss resistance, as I said earlier, you need to consider not only the increased conductor length, but also the non-uniform current distribution on the multi-turn conductor surface caused by the proximity effect, which will cause underutilization of the conductor surface and thus an increase in ohmic loss. The following article is a good read for anyone interested in practical multi-turn small-transmitting loops. Best regards, qrp.gaijin@... |
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Re: Multiiturn loop antanna
Rick wrote: ? ?"Adding loops raises the impedance which means the same power will have a higher voltage and lower current after matching.? This in turn means the I2R losses will be lower in spite of the higher resistance." Good point. Then I suppose the question would be, what does the radiation resistance do when using two or more turns in series? If it varies the same as inductance (~4X for 2 turns), then it'd be a big win. Andy |
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Re: Multiiturn loop antanna
Yes, you are absolutely right.? I'm down with a cold and there is no room left for doing things in my head, lol.? As you say, for constant power to the antenna the voltage will double and the current will halve.? Using I2R the resistive power loss will be cut in half, not 1/8 as I wrote before.
I don't know if it is common to link antenna efficiency to Q, but in this case the equations seem to be the same.? It is the ratio of the inductive reactance to the resistance, as long as the reactance dominates.? Rick |
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Re: Multiiturn loop antanna
The efficiency improves with larger diameter conductors. Some day I would like to own one of those large Harbor Freight tubing benders so I can make loops with 1" copper pipe. Chris When the going gets weird, the weird turn pro - Hunter S. Thompson |
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Re: Multiiturn loop antanna
¿ªÔÆÌåÓý? Rick, I assume you want to make your comparison for the situation where the power remains the same. In that case a four times higher impedance results in a voltage that is twice as high and a current that is halved. So the resulting power loss is 1/2 ?instead of 1/8. Or is it me who¡¯s wrong? But the meaning of your statement does not change. ? Cor PA4Q |
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Re: Multiiturn loop antanna
Hi Rick,
Thank you for that information. I am using 1 inch diameter heliax and wanted a size reduction without a performance reduction. 73;s Colin? ZL1BTT |
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