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Antenna blues, so far my Sony AN-1 wins!
Hello All,
Picking up my SWL hobby wich I left in ~ 1992. I have a Phillips D2999PLL and Sony AN-1 which I have kept from back then. My living situation is far worse (for SWL that is) compared to back then when living ina quiet suburb. Living in the city centre now with a supermarket with huge fans on their roof for cooling the freezers and such, and ofcourse all the equipment from our neighbours. So I've been reading the forums, sites and newsgroups on my equipment and found that generally the receiver is well received (*g*), and the antenna is not! Back then though I've been able to receive quite a bunch of QSL cards from stations I picked up in the tropical bands. Had lots and lotsof night of fun! But, to improve my antenna situation I've been looking around to see for alternatives. Active antenna's are out of the question for me. Frick, the quality ones seem to start at 200Euro. As a soon to be daddy and other expenses coming up I can't afford those... I've little room for a reasonable 'random wire' either. After some looking around I decided to give the EMF antenna a try from RF-Systems in the Netherlands (where I come from as well, accidentally). After a few days of trying different configurations (indoors, out on the balcony, horizontal, vertical, north-south, west-east and all inbetween, 30 degree sloped, earthing to the earthwire in the powerbox of the appartment, etc) and comparing it to my Sony AN-1, I can savely say, at best the EMF antenna produces equally to the Sony An-1, but has never exceeded it. It seems to pickup far more noise and interference then the AN-1 does. So the EMF is up for grabs for anyone here who makes a good offer for it! I also have to add, I did quite some browsing and reading on the EMF before I ordered it, and the general tendency was it is an OK antenna. I guess, in my situation the AN-1 isnt such a bad antenna after all, or the EMF is for my situation a really bad antenna! This week I am going to try and build a magnetic loop. At first I saw many daunting schematics which are too technical for me with my left hands, but I found this page (http://www.kr1st.com/swlloop.htm) with a *very* simple version that according to the writer is so simple as it is for receiving only. Apparently, the transmitting ones need to be far more technical. Does anyone has any tips regarding building any of these? My particular interest is the 60meter band. And, anyone any comments on my EMF/AN-1 comparison? I think I pretty much tried all configurations, and in reality there isnt much to do with the EMF, its all prebuild. But I'm open for suggestions! |
Antenna blues, so far my Sony AN-1 wins!
Jeroen wrote: Hello All, Picking up my SWL hobby wich I left in ~ 1992. I have a Phillips D2999PLL and Sony AN-1 And, anyone any comments on my EMF/AN-1 comparison? I think I pretty much tried all configurations, and in reality there isnt much to do with the EMF, its all prebuild. But I'm open for suggestions! .................................................. .................................................. ............................ I used an AN-1 in a concrete apartment for a year and it worked well after I had made a change to it. Unmodified, it was quiet, didn't hurt the signals but it didn't seem to have much gain. I added a thin hustler 2 meter 5/8 whip to the end of the AN-1 whip (about 4 feet as I recall) and that improved it consiserably. I think that Sony was worried about generating spurious in high-signal areas like Europe and used very a conservative amplifier. Adding a length to the whip in weak-signal areas had no bad effects. |
Antenna blues, so far my Sony AN-1 wins!
In article . com,
"ve3..." wrote: Jeroen wrote: Hello All, Picking up my SWL hobby wich I left in ~ 1992. I have a Phillips D2999PLL and Sony AN-1 And, anyone any comments on my EMF/AN-1 comparison? I think I pretty much tried all configurations, and in reality there isnt much to do with the EMF, its all prebuild. But I'm open for suggestions! .................................................. ............................ ................................................. I used an AN-1 in a concrete apartment for a year and it worked well after I had made a change to it. Unmodified, it was quiet, didn't hurt the signals but it didn't seem to have much gain. I added a thin hustler 2 meter 5/8 whip to the end of the AN-1 whip (about 4 feet as I recall) and that improved it consiserably. I think that Sony was worried about generating spurious in high-signal areas like Europe and used very a conservative amplifier. Adding a length to the whip in weak-signal areas had no bad effects. The advantage of this small active antenna is you can put it in the quietest location of you house. Go around with a portable radio to find a quite spot and mount the AN-1 there. -- Telamon Ventura, California |
Antenna blues, so far my Sony AN-1 wins!
In article om,
"Jeroen" wrote: Hello All, Picking up my SWL hobby wich I left in ~ 1992. I have a Phillips D2999PLL and Sony AN-1 which I have kept from back then. My living situation is far worse (for SWL that is) compared to back then when living ina quiet suburb. Living in the city centre now with a supermarket with huge fans on their roof for cooling the freezers and such, and ofcourse all the equipment from our neighbours. So I've been reading the forums, sites and newsgroups on my equipment and found that generally the receiver is well received (*g*), and the antenna is not! Back then though I've been able to receive quite a bunch of QSL cards from stations I picked up in the tropical bands. Had lots and lotsof night of fun! But, to improve my antenna situation I've been looking around to see for alternatives. Active antenna's are out of the question for me. Frick, the quality ones seem to start at 200Euro. As a soon to be daddy and other expenses coming up I can't afford those... I've little room for a reasonable 'random wire' either. After some looking around I decided to give the EMF antenna a try from RF-Systems in the Netherlands (where I come from as well, accidentally). After a few days of trying different configurations (indoors, out on the balcony, horizontal, vertical, north-south, west-east and all inbetween, 30 degree sloped, earthing to the earthwire in the powerbox of the appartment, etc) and comparing it to my Sony AN-1, I can savely say, at best the EMF antenna produces equally to the Sony An-1, but has never exceeded it. It seems to pickup far more noise and interference then the AN-1 does. So the EMF is up for grabs for anyone here who makes a good offer for it! I also have to add, I did quite some browsing and reading on the EMF before I ordered it, and the general tendency was it is an OK antenna. I guess, in my situation the AN-1 isnt such a bad antenna after all, or the EMF is for my situation a really bad antenna! This week I am going to try and build a magnetic loop. At first I saw many daunting schematics which are too technical for me with my left hands, but I found this page (http://www.kr1st.com/swlloop.htm) with a *very* simple version that according to the writer is so simple as it is for receiving only. Apparently, the transmitting ones need to be far more technical. Does anyone has any tips regarding building any of these? My particular interest is the 60meter band. And, anyone any comments on my EMF/AN-1 comparison? I think I pretty much tried all configurations, and in reality there isnt much to do with the EMF, its all prebuild. But I'm open for suggestions! Small active loop antennas are pricey but are most likely the best in town choice. To get an idea how this type of antenna will work in your location you could build a passive loop at small cost using just coax cable. -- Telamon Ventura, California |
Antenna blues, so far my Sony AN-1 wins!
Hello All,
Thanks for your replies. Here some reactions from my side: I used an AN-1 in a concrete apartment for a year and it worked well after I had made a change to it. Unmodified, it was quiet, didn't hurt the signals but it didn't seem to have much gain. I added a thin hustler 2 meter 5/8 whip to the end of the AN-1 whip (about 4 feet as I recall) and that improved it consiserably. I think that Sony was worried about generating spurious in high-signal areas like Europe and used very a conservative amplifier. Adding a length to the whip in weak-signal areas had no bad effects. I did this as well, I do live in Europe (Holland) and it increased the noise heavily, making it not really usefull for me. Small active loop antennas are pricey but are most likely the best in town choice. Unfortunally, no money for that :\ To get an idea how this type of antenna will work in your location you could build a passive loop at small cost using just coax cable. This is what I am going to do. Aftre some digging around I will go for copper tubing however, as on one site I found that on lower frequencies thicker copper will do better then the thinner one advised in the article I gave the URL for. I'm looking forward to building somehting of my own though! And I'll probably experiment afterwards to improve the results. Can't wait to see wether it will outperform my AN-1 antenna.... The costs are, like you said, minimal. I'll post back when I have done some testing on my to-be magnetic loop :) |
Antenna blues, so far my Sony AN-1 wins!
In article . com,
"Jeroen" wrote: Hello All, Thanks for your replies. Here some reactions from my side: I used an AN-1 in a concrete apartment for a year and it worked well after I had made a change to it. Unmodified, it was quiet, didn't hurt the signals but it didn't seem to have much gain. I added a thin hustler 2 meter 5/8 whip to the end of the AN-1 whip (about 4 feet as I recall) and that improved it consiserably. I think that Sony was worried about generating spurious in high-signal areas like Europe and used very a conservative amplifier. Adding a length to the whip in weak-signal areas had no bad effects. I did this as well, I do live in Europe (Holland) and it increased the noise heavily, making it not really usefull for me. Small active loop antennas are pricey but are most likely the best in town choice. Unfortunally, no money for that :\ To get an idea how this type of antenna will work in your location you could build a passive loop at small cost using just coax cable. This is what I am going to do. Aftre some digging around I will go for copper tubing however, as on one site I found that on lower frequencies thicker copper will do better then the thinner one advised in the article I gave the URL for. I'm looking forward to building somehting of my own though! And I'll probably experiment afterwards to improve the results. Can't wait to see wether it will outperform my AN-1 antenna.... The costs are, like you said, minimal. I'll post back when I have done some testing on my to-be magnetic loop :) You don't have to use copper tubing. You can build the antenna using just the coax. If you build a 40 foot loop you would build it like this: 1. Cut a piece of coax 40 feet long. 2. Cut the shield only at 20 feet separate the shield about an inch. 3. Bring the ends of the loop together connecting the shields and center conductor on one end. 4. Connect the shield of the lead-in coax shield to the shields of the loop and the remaining free center conductor of the loop to the center conductor of the lead-in coax. The loop will be somewhat unbalanced but should work pretty good. You can improve the balance of the loop by using a BALUN made of enamel coated wire and a ferrite toroid core. If you use the BALUN you would have both ends of the loop center conductors connected to a bifilar winding on the core of a few turns where the other end of the winding is connected to the lead-in center conductor and common ground made of both end of the loop shields and the lead-in shield. All this should only cost under $50 dollars. -- Telamon Ventura, California |
Antenna blues, so far my Sony AN-1 Wins !
Jeroen wrote: Hello All, Picking up my SWL hobby wich I left in ~ 1992. I have a Phillips D2999PLL and Sony AN-1 which I have kept from back then. My living situation is far worse (for SWL that is) compared to back then when living ina quiet suburb. Living in the city centre now with a supermarket with huge fans on their roof for cooling the freezers and such, and ofcourse all the equipment from our neighbours. So I've been reading the forums, sites and newsgroups on my equipment and found that generally the receiver is well received (*g*), and the antenna is not! Back then though I've been able to receive quite a bunch of QSL cards from stations I picked up in the tropical bands. Had lots and lotsof night of fun! But, to improve my antenna situation I've been looking around to see for alternatives. Active antenna's are out of the question for me. Frick, the quality ones seem to start at 200Euro. As a soon to be daddy and other expenses coming up I can't afford those... I've little room for a reasonable 'random wire' either. After some looking around I decided to give the EMF antenna a try from RF-Systems in the Netherlands (where I come from as well, accidentally). After a few days of trying different configurations (indoors, out on the balcony, horizontal, vertical, north-south, west-east and all inbetween, 30 degree sloped, earthing to the earthwire in the powerbox of the appartment, etc) and comparing it to my Sony AN-1, I can savely say, at best the EMF antenna produces equally to the Sony An-1, but has never exceeded it. It seems to pickup far more noise and interference then the AN-1 does. So the EMF is up for grabs for anyone here who makes a good offer for it! I also have to add, I did quite some browsing and reading on the EMF before I ordered it, and the general tendency was it is an OK antenna. I guess, in my situation the AN-1 isnt such a bad antenna after all, or the EMF is for my situation a really bad antenna! This week I am going to try and build a magnetic loop. At first I saw many daunting schematics which are too technical for me with my left hands, but I found this page (http://www.kr1st.com/swlloop.htm) with a *very* simple version that according to the writer is so simple as it is for receiving only. Apparently, the transmitting ones need to be far more technical. Does anyone has any tips regarding building any of these? My particular interest is the 60meter band. And, anyone any comments on my EMF/AN-1 comparison? I think I pretty much tried all configurations, and in reality there isnt much to do with the EMF, its all prebuild. But I'm open for suggestions! Jeroen, The RF Systems "EMF" Antenna is relatively short at 16 Feet and is a magnetically coupled Antenna. The signal levels are thus relatively small compared to a much longer 50-80 Foot Random Wire Antenna. So -Yes- in this instance you may find that the Sony AN-1 Active Antenna does as well or better than the "EMF". Don't forget that the Sony AN-1 Active Antenna : * Should be Mounted at least 3-5 Feet above your Roof -or- at least 15-20 Feet away from your House/Building. * Can be Mounted inside the Attic. * Can be Mounted Horizontally and Rotated to Null-Out the main source of your local Noise to some degree. {every little bit helps :o} Alternative - Instead of using the Sony AN-1 Active Antenna's Short Vertical Whip Antenna Element : Use a One Metre Diameter Horizontal Loop Antenna Element with one-end of the Loop connected directly to the Sony's Head Unit and the other-end of the Loop connected via a 300, 450, 600 or 1K Ohm Resister to the Sony's Head Unit. Try the different Resisters to determine which gives the best Signal Levels and overall frequency coverage. Note - Sometimes the sort of Terminated Horizontal Loop Antenna Element will provide lower noise levels and better Radio reception then the simple Vertical Whip Antenna Element. Usually this type of Terminated Horizontal Loop Antenna Element is installed in an Attic Area. iane ~ RHF |
The single-turn Coax Cable {Shielded} Loop Antenna for basic Shortwave Radio Listening (SWL) - It Works !
Telamon wrote: In article om, "Jeroen" wrote: Hello All, Picking up my SWL hobby wich I left in ~ 1992. I have a Phillips D2999PLL and Sony AN-1 which I have kept from back then. My living situation is far worse (for SWL that is) compared to back then when living ina quiet suburb. Living in the city centre now with a supermarket with huge fans on their roof for cooling the freezers and such, and ofcourse all the equipment from our neighbours. So I've been reading the forums, sites and newsgroups on my equipment and found that generally the receiver is well received (*g*), and the antenna is not! Back then though I've been able to receive quite a bunch of QSL cards from stations I picked up in the tropical bands. Had lots and lotsof night of fun! But, to improve my antenna situation I've been looking around to see for alternatives. Active antenna's are out of the question for me. Frick, the quality ones seem to start at 200Euro. As a soon to be daddy and other expenses coming up I can't afford those... I've little room for a reasonable 'random wire' either. After some looking around I decided to give the EMF antenna a try from RF-Systems in the Netherlands (where I come from as well, accidentally). After a few days of trying different configurations (indoors, out on the balcony, horizontal, vertical, north-south, west-east and all inbetween, 30 degree sloped, earthing to the earthwire in the powerbox of the appartment, etc) and comparing it to my Sony AN-1, I can savely say, at best the EMF antenna produces equally to the Sony An-1, but has never exceeded it. It seems to pickup far more noise and interference then the AN-1 does. So the EMF is up for grabs for anyone here who makes a good offer for it! I also have to add, I did quite some browsing and reading on the EMF before I ordered it, and the general tendency was it is an OK antenna. I guess, in my situation the AN-1 isnt such a bad antenna after all, or the EMF is for my situation a really bad antenna! This week I am going to try and build a magnetic loop. At first I saw many daunting schematics which are too technical for me with my left hands, but I found this page (http://www.kr1st.com/swlloop.htm) with a *very* simple version that according to the writer is so simple as it is for receiving only. Apparently, the transmitting ones need to be far more technical. Does anyone has any tips regarding building any of these? My particular interest is the 60meter band. And, anyone any comments on my EMF/AN-1 comparison? I think I pretty much tried all configurations, and in reality there isnt much to do with the EMF, its all prebuild. But I'm open for suggestions! - - Small active loop antennas are pricey but - are most likely the best in town choice. - - To get an idea how this type of antenna will work in your location you - could build a passive loop at small cost using just coax cable. - - -- - Telamon - Ventura, California Telamon - Yes I Agreed - The single-turn Coax Cable {Shielded} Loop Antenna for basic Shortwave Radio Listening (SWL) is one of the better choices for ease of construction and utility. http://www.iri.tudelft.nl/~geurink/i..._schematic.jpg READ ABOUT - THe Coax Cable {Shielded} Loop Antenna [GreerTech] http://groups.google.com/group/rec.r...7b1501f08ffebe http://groups.google.com/group/rec.r...03fed7472a9e53 http://groups.google.com/group/rec.r...8005ce8c7f5c9c http://groups.google.com/group/rec.r...f9f216217d3420 http://groups.google.com/group/rec.r...6e2b951e35abd9 http://groups.google.com/group/rec.r...52a8e37790a367 http://groups.google.com/group/rec.r...8005ce8c7f5c9c http://groups.google.com/group/rec.r...dc49a6c156fa2b "Low Noise Receive-Only Coax Cable Loop Antennas for the 160 Meter to 10 Meter Shortwave {High Frequency} Bands" http://www.greertech.com/hfloop/mymagloop.html The so called GREER TECH "Coax Loop" Antenna. The "TRICK" to TV 'type' Coax Cable [Shielded] SWL Loop Antennas http://groups.google.com/group/rec.r...a0aadd03af7bc7 Hula Hoop Loop Antenna and more . . . http://groups.google.com/group/rec.r...fc1c535a7e8169 The basic design of the "GreerTech" Coax Cable [Shielded] Loop Antenna is good and very practical. GREERTECH = http://www.greertech.com/hfloop/mymagloop.html LOOP= http://www.greertech.com/hfloop/mymagloop.html http://groups.yahoo.com/group/Shortw...a/message/1625 http://groups.yahoo.com/group/Shortw...a/message/1730 http://groups.yahoo.com/group/Shortw...a/message/1539 http://groups.yahoo.com/group/Shortw...a/message/1008 FWIW - 'other' "Shielded-Magnetic" Loop Receiving Antenna WebPages to Check-Out : http://www.io.com/~n5fc/loop_ant.html http://user.netonecom.net/~swordman/Radio/shloopant.htm http://www.qsl.net/mnqrp/Loop/Mag_Loops.htm http://beradio.com/news/radio_shield..._am_antenna_2/ http://www.iri.tudelft.nl/~geurink/magnloop.htm http://www.hard-core-dx.com/nordicdx.../coaxloop.html ABOUT - Loop Antennas: http://www.frontiernet.net/~jadale/Loop.htm - 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 keeping you in the loop when it comes to shortwave antennas cause . . . iane ~ RHF . Shortwave Listener Antennas = http://tinyurl.com/ogvcf http://groups.yahoo.com/group/Shortwave-SWL-Antenna/ SWL Antenna Group = http://tinyurl.com/ogvcf . The Shortwave Listener's Blessing : SWL BLESSING = http://tinyurl.com/s2bjm May You Never Tire of Listening to the Radio and Always have Strong Signals and Noise Free Reception ~ RHF {ibid} http://groups.yahoo.com/group/Shortw...a/message/9233 . Tous Sont Bienvenus ! - - - Groupe par Radio d'auditeur d'onde courte pour des Antennes de SWL http://groups.yahoo.com/group/Shortwave-SWL-Antenna/ . Alle Sind Willkommen ! - - - Shortwave Radiozuhörer Gruppe für SWL Antennen http://groups.yahoo.com/group/Shortwave-SWL-Antenna/ . Tutti Sono Benvenuti ! - - - Gruppo Radiofonico dell'ascoltatore di onda corta per le Antenne di SWL http://groups.yahoo.com/group/Shortwave-SWL-Antenna/ . Todos São Bem-vindos ! - - - Grupo de Rádio do ouvinte do Shortwave para Antenas de SWL http://groups.yahoo.com/group/Shortwave-SWL-Antenna/ . Все *адушны ! - - - Группа оператора на приеме коротковолнового диапазона Radio для Aнтенн SWL http://groups.yahoo.com/group/Shortwave-SWL-Antenna/ . ¡Todos Son Agradables! - - - Grupo de Radio del oyente de la onda corta para las Antenas de SWL http://groups.yahoo.com/group/Shortwave-SWL-Antenna/ . = = = = = = = = = = Translation = = = = = = = = = = All are Welcome - - - To Join the Shortwave Listeners (SWL) Antenna Group on YAHOO ! http://groups.yahoo.com/group/Shortwave-SWL-Antenna/ . | | | / \ -------!------- |
Antenna blues, so far my Sony AN-1 Wins !
RHF wrote: Alternative - Instead of using the Sony AN-1 Active Antenna's Short Vertical Whip Antenna Element : Use a One Metre Diameter Horizontal Loop Antenna Element with one-end of the Loop connected directly to the Sony's Head Unit and the other-end of the Loop connected via a 300, 450, 600 or 1K Ohm Resister to the Sony's Head Unit. Try the different Resisters to determine which gives the best Signal Levels and overall frequency coverage. This could be an interetsing experiment :) I've already bought coppertubing and so to make the loop as described on that previous page, so if that turns to be a failed experiment, I might use it for this ;) Just to clarify (I blame my non-native knowledge of English): So one end of the loop to the element where the whip is normally attached to, and the other to the unit with the switches? And, do I connect the loop to the 'inside' connector of the box? Nothing needs to be connected to the shielding? I'd love to see a schematic if possible... |
Antenna blues, so far my Sony AN-1 Wins !
Jeroen wrote: RHF wrote: Alternative - Instead of using the Sony AN-1 Active Antenna's Short Vertical Whip Antenna Element : Use a One Metre Diameter Horizontal Loop Antenna Element with one-end of the Loop connected directly to the Sony's Head Unit and the other-end of the Loop connected via a 300, 450, 600 or 1K Ohm Resister to the Sony's Head Unit. Try the different Resisters to determine which gives the best Signal Levels and overall frequency coverage. This could be an interetsing experiment :) I've already bought coppertubing and so to make the loop as described on that previous page, so if that turns to be a failed experiment, I might use it for this ;) Just to clarify (I blame my non-native knowledge of English): So one end of the loop to the element where the whip is normally attached to, and the other to the unit with the switches? And, do I connect the loop to the 'inside' connector of the box? Nothing needs to be connected to the shielding? I'd love to see a schematic if possible... Jeroen, Where the Whip Antenna Mast screws-on-to the top of the Mast-Screw of the Sony AN-1 Active Antenna's Head Unit. 1 - Attach one-end of the Loop. (Use a Nut and Washer) 2 - Attach the other-end of the Loop to the Resister. 3 - Attach the free-end of the Resister to the Mast-Screw. Just a plain simple Wire Horizontal Loop Element. * You could use Stranded Wire or Litz Wire and Copper Tubing or even the Outer-Shield of a Coax Cable would be OK too. * The shape of the Loop could be Round, Square, Triangle, Diamond, Octagon, etc. * One Meter Diameter or per Side * Length of Wire in the Loop about 10-12 Feet. iane ~ RHF |
Antenna blues, so far my Sony AN-1 Wins !
I've built that magnetic loop yesterday according to Kr1sts' schematic.
I'm impressed! I was really wondering how it would work against the An-1, and sofar it seems to work at least equal as good, and then you have to add in the benefits of it being directional. Naturally, having to 'tune in' all the time makes it a bit less practical. I also got it to start tuning from about 4400KHz (hurray). I found a cheap ~ 15$ building package for an antenna amplifier (unfortunally 10-140MHz, not covering my fav. the 60 meter) which might be a good experiment to further boost the performance of this hobby project. If anyone knows of idiotproof schematics (I have about zero knowledge of building electronics) that would also include the 60 meter band, that would be awesome. |
Antenna blues, so far my Sony AN-1 Wins !
Jeroen wrote:
If anyone knows of idiotproof schematics (I have about zero knowledge of building electronics) that would also include the 60 meter band, that would be awesome. There should be something of use he http://snipurl.com/w37d god luck in your new project. mike |
Antenna blues, so far my Sony AN-1 Wins !
In article .com,
"Jeroen" wrote: I've built that magnetic loop yesterday according to Kr1sts' schematic. I'm impressed! I was really wondering how it would work against the An-1, and sofar it seems to work at least equal as good, and then you have to add in the benefits of it being directional. Naturally, having to 'tune in' all the time makes it a bit less practical. I also got it to start tuning from about 4400KHz (hurray). I found a cheap ~ 15$ building package for an antenna amplifier (unfortunally 10-140MHz, not covering my fav. the 60 meter) which might be a good experiment to further boost the performance of this hobby project. If anyone knows of idiotproof schematics (I have about zero knowledge of building electronics) that would also include the 60 meter band, that would be awesome. Who is Kr1sts? How did you build it? -- Telamon Ventura, California |
Antenna blues, so far my Sony AN-1 Wins !
In article . com,
"Jeroen" wrote: Who is Kr1sts? How did you build it? http://www.kr1st.com/swlloop.htm Mostly according to this article. It was really easy to build. Hardest was to find a proper capacitor wich I eventually found in my girlfriends alarmclock (lol). I'm going to skip the amplifier, after some research I learned that it'll only amplify the whole sound, and adda bit of noise to it as well, so it won't do me much good. Instead I'm going to build another loop, geared towards the 60 meter in specific. It will be a multiple turn loop made of a 1/10 wavelenght copper tube. More information can be found he http://home.datacomm.ch/hb9abx/loop80m-e.htm I'll start by using the capacitor they advise there, a 10-125pF so 3.9 to 10 MHz will be covered, including my fav. the 60 meters and an amateurband I regurarly listen to. I'm really enthousiastic in magn.loops after this first experiment, and might have a AN-1 for sale in a not too long time from now. I heard (on this newsgroup) one fetched 200$ a week or so ago on eBay?!? That'll be great and allows me to build 4 more magnetic loops! ;) The first link is a manually tuned loop and the second is a motorized version of the same. A tuned loop will be quieter than a broadband loop design I posted earlier. The drawback with the tuned loop is you have to tune it along with the radio complicating the operation of tuning in a station. Looking at the first link I think the design would work better if there was more separation between the pickup loop and the tuned loop. I would attach the pickup loop on the other side of the PVC pipe. The second suggestion is to use a series 50 ohm resistor from the coax center conductor to the pickup loop. This may not do much other than sharpen the peak of the tuning response. -- Telamon Ventura, California |
Antenna blues, so far my Sony AN-1 Wins !
In article om,
"Jeroen" wrote: Telamon wrote: The first link is a manually tuned loop and the second is a motorized version of the same. A tuned loop will be quieter than a broadband loop design I posted earlier. I posted the second link as it offers more information about the circumvence of the loop, and the possibility about making the loop multiple turns, and how the distance between those tunrs affect the range the loops works best for. Those are all info not present in the first. The drawback with the tuned loop is you have to tune it along with the radio complicating the operation of tuning in a station. I have it in the livingroom becuase of that, haha. It's indeed a bit less practical. The overall bandwidth thats tuned into is about 100Khz. So its doable to browse the 60 meter band for example. Looking at the first link I think the design would work better if there was more separation between the pickup loop and the tuned loop. I would attach the pickup loop on the other side of the PVC pipe. Hmm that is interesting, and something I want to experiemnt with. In the testing phase, with simply holding an antenna of a portable close to the loop, I found that the closer, the better... The second suggestion is to use a series 50 ohm resistor from the coax center conductor to the pickup loop. This may not do much other than sharpen the peak of the tuning response. From a SWL in the Netehrlands I've understood that the whole point of using the coupling loop is to make the input into the antenna 50 ohm. Why would adding a 50 ohm resistor improve things further? Thanks for your help, learning so much about antenna's doing all this building, experiementing and asking around! :) The pickup loop will look like a short on the end of the coax at some frequencies and the resistor will cause the impedance to be a minimum of 50 ohms. You don't want the two loops to actually touch each other and mounting the pickup on the other side of the PVC pipe is an easy way to accomplish that. -- Telamon Ventura, California |
Antenna blues, so far my Sony AN-1 Wins !
Telamon wrote: You don't want the two loops to actually touch each other and mounting the pickup on the other side of the PVC pipe is an easy way to accomplish that. Yes, but why not allow them to touch eachother? What's the reason for it? Just hoping to get a (physics) reason for why they shouldnt be too close togheter, jst to further udnerstand the nature of the thing better :) I havent came acros any descriptions that said they shouldnt be too close, so I'm really curious. Thanks, Jeroen |
Antenna blues, so far my Sony AN-1 Wins !
In article .com,
"Jeroen" wrote: Telamon wrote: You don't want the two loops to actually touch each other and mounting the pickup on the other side of the PVC pipe is an easy way to accomplish that. Yes, but why not allow them to touch eachother? What's the reason for it? Just hoping to get a (physics) reason for why they shouldnt be too close togheter, jst to further udnerstand the nature of the thing better :) I havent came acros any descriptions that said they shouldnt be too close, so I'm really curious. Two things referring to the link http://www.kr1st.com/swlloop.htm 1. The tuned loop and pickup loop are supposed to couple magnetically. The tuned loop is bare copper and it looks like the pickup is made of bare wire so if they touch they will have a direct circuit connection. If you use magnet wire for the pickup you are counting on a thin layer of enamel paint to insulate one from the other, which can easily be abraded. 2. One parameter controlling Magnetic coupling between the loops is distance. You already know this and the loop will tune a little sharper if the pickup loop does not load it as much as when the loops are physically together. -- Telamon Ventura, California |
Antenna blues, so far my Sony AN-1 Wins !
Ah ok. Obviously at least one of the loops is insulated here (that
wouldve been a joke ;) ). I'll experiment with the distance here and see what differences it makes. I also noted that different setups can affect different type of stations in different ways again. What can benefit stations hidden in static (tropical dx) can worse reception of SSB stations that are strong, and ofcourse, the other way around. Fun stuff, making your own antenna for sure! |
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