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#1
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![]() "Joe Analssandrini" wrote in message oups.com... Hello, I just finished reading all the posts here to date (June 16, 2005 at 2040 UTC) and I must say that most of the replies to you are well-reasoned and thought out. I think that if you follow many of the suggestions that have been written, you will be pleased with the results you obtain. May I make my suggestion for a good receiver/antenna combination? Go on to the Universal site and look at ther AOR AR7030 Plus receiver. I have had one for over a year now and each day I am more impressed with it. In addition to being a superb receiver, one of the finest ever designed, it can also be controlled from your computer via a free computer program called RxWings, if you are interested in that sort of thing. I've been using this computer program for almost as long as I have owned the receiver and it is, in my opinion, first-rate. I would recommend buying the NB7030 Noise Blanker/Notch Filter option for the radio. I've gone to Universal Radio's website and read about the AOR AR7030+ reciever and did a google search for reviews on it as well. It would seem that it would be a great pick for a top-notch DXing setup! As for an antenna, it seems that you, like me, live in an electrically-noisy location. Yes those power lines 250 meters away from your location are going to cause problems (as you have already discovered). The solution? A Wellbrook ALA 330S Active Loop Antenna, in my opinion the finest shortwave antenna currently on the market. You can go to Wellbrook's website to view all the particulars; you would buy it from THE SHORTWAVE SHOP in the UK (Wellbrook's only dealer) if you want to use a credit card. The results achievable with this antenna in an electrically-noisy location are nothing short of astounding. A TV rotator is helpful as the antenna, like all loops, exhibits directionality especially at lower frequencies and you might as well take advantage of this functionality. Actually, I now think some if not most of the noise problems are internal to my house rather than external. I poked around in my backyard last night with my portable radio, and to my surprise most of the noise was gone. I also checked out my front yard and found it was somewhat noisier, but it's also the side closest to the power substation, so perhaps my house is providing a bit of shielding from it? I'm wondering if some sort of low mounted outdoor antenna might be my best bet. I'm thinking that if I get it too high up in the air then it would be more line-of-sight to the power substation and might be noisy again. (Maybe I ought to take my portable up on the roof and see what I get up there?) That combination, the AOR AR7030 Plus (with the NB7030) and the Wellbrook ALA 330S is not cheap. Nor is the antenna "convenient" to buy. And, especially, the installation of the antenna is quite a precise affair - you must be willing to carefully read and follow (to the letter) the quite-clear installation instructions (with one exception: placement of the antenna is not at all critical as the instructions suggest; I have mine mounted in my attic on a Radio Shack rotator where it performs superbly; it can be mounted outdoors, high or low - even on a deck rail or fence post). I've also read some reviews on this antenna, and most if not all gave it rave reviews. He's a review that I found interesting and helpful. http://www.radiointel.com/review-wellbrook.htm The learning curve of the AOR AR7030 Plus, though nowhere nearly as difficult as PASSPORT purports, is still something that must be mastered. (Of course this applies to any communications receiver; it's not enough to know what buttons to press; you have to know when and under what circumstances to press them! This comes only with experience.) All that notwithstanding, if you can afford it (and apparently you can), the results obtainable with the AR7030 Plus and the Wellbrook ALA 330S are well-worth the money!! I wish you the very best of luck with whatever you purchase. Joe Thanks Joe. Your post was very helpful to this shortwave newbie! |
#2
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In article 1119208556.bdf46749713b734146fe6f29f1b9f3b9@megan etnews2,
"Wannabe DXer" wrote: "Joe Analssandrini" wrote in message oups.com... Hello, I just finished reading all the posts here to date (June 16, 2005 at 2040 UTC) and I must say that most of the replies to you are well-reasoned and thought out. I think that if you follow many of the suggestions that have been written, you will be pleased with the results you obtain. May I make my suggestion for a good receiver/antenna combination? Go on to the Universal site and look at ther AOR AR7030 Plus receiver. I have had one for over a year now and each day I am more impressed with it. In addition to being a superb receiver, one of the finest ever designed, it can also be controlled from your computer via a free computer program called RxWings, if you are interested in that sort of thing. I've been using this computer program for almost as long as I have owned the receiver and it is, in my opinion, first-rate. I would recommend buying the NB7030 Noise Blanker/Notch Filter option for the radio. I've gone to Universal Radio's website and read about the AOR AR7030+ reciever and did a google search for reviews on it as well. It would seem that it would be a great pick for a top-notch DXing setup! As for an antenna, it seems that you, like me, live in an electrically-noisy location. Yes those power lines 250 meters away from your location are going to cause problems (as you have already discovered). The solution? A Wellbrook ALA 330S Active Loop Antenna, in my opinion the finest shortwave antenna currently on the market. You can go to Wellbrook's website to view all the particulars; you would buy it from THE SHORTWAVE SHOP in the UK (Wellbrook's only dealer) if you want to use a credit card. The results achievable with this antenna in an electrically-noisy location are nothing short of astounding. A TV rotator is helpful as the antenna, like all loops, exhibits directionality especially at lower frequencies and you might as well take advantage of this functionality. Actually, I now think some if not most of the noise problems are internal to my house rather than external. I poked around in my backyard last night with my portable radio, and to my surprise most of the noise was gone. I also checked out my front yard and found it was somewhat noisier, but it's also the side closest to the power substation, so perhaps my house is providing a bit of shielding from it? I'm wondering if some sort of low mounted outdoor antenna might be my best bet. I'm thinking that if I get it too high up in the air then it would be more line-of-sight to the power substation and might be noisy again. (Maybe I ought to take my portable up on the roof and see what I get up there?) That combination, the AOR AR7030 Plus (with the NB7030) and the Wellbrook ALA 330S is not cheap. Nor is the antenna "convenient" to buy. And, especially, the installation of the antenna is quite a precise affair - you must be willing to carefully read and follow (to the letter) the quite-clear installation instructions (with one exception: placement of the antenna is not at all critical as the instructions suggest; I have mine mounted in my attic on a Radio Shack rotator where it performs superbly; it can be mounted outdoors, high or low - even on a deck rail or fence post). I've also read some reviews on this antenna, and most if not all gave it rave reviews. He's a review that I found interesting and helpful. http://www.radiointel.com/review-wellbrook.htm The learning curve of the AOR AR7030 Plus, though nowhere nearly as difficult as PASSPORT purports, is still something that must be mastered. (Of course this applies to any communications receiver; it's not enough to know what buttons to press; you have to know when and under what circumstances to press them! This comes only with experience.) All that notwithstanding, if you can afford it (and apparently you can), the results obtainable with the AR7030 Plus and the Wellbrook ALA 330S are well-worth the money!! I wish you the very best of luck with whatever you purchase. Joe Thanks Joe. Your post was very helpful to this shortwave newbie! I came to the conclusion years ago that loop type antennas are the best bet for most people. The amplified loops can be made smaller and due to size you have more options where to locate it but they are more expensive than the passive loops. You can build a shielded passive loop out of coax. A general purpose one of 40 to 60 foot circumference should be electrically balanced and the smaller ones ( 20 foot) can be non-balanced for more gain. The small non-balanced ones pickup both the E and M fields of a passing EM wave where the balanced one picks up the M part only. The difference between the balanced and unbalanced is where the shield is split. Say you take a 50 foot piece and loop it back on itself ten feet from one end. At that point you solder the center conductor of the end of the cable to the shield. The the outer shield of the cable is not connected and floats. The 10 foot section behaves as a transmission line to the radio in this example. This will probably be to much antenna on the lower bands for most table top or any sensitive radio. This is not a shielded loop. This loop is high output and responds to both the E and M fields, which is why you have a larger output. To make a balanced loop at that 10 foot point you solder both the center conductor and shield of the cable end to the coax shield. Then half way around the loop you cut the outer insulator and shield only. Now you have a balanced loop that only responds to the M field. The output will be less but so will the local noise that is limiting your reception. The balanced loop is shielded against local common mode E field noise. This balanced loop will be the most like the Wellbrook if you can manage to get it some distance from local noise sources. You need it to be some distance away from the local noise sources so the noise field is equal over the area of the loop so it can be canceled. Here a small 1 meter loop like the Wellbrook has the advantage. It can be much closer to local noise sources and cancel them out. Another advantage the Wellbrook has is flatter response over the 3 to 30MHz range. The response of the passive loop will change over that range depending on its size but not a lot. Another advantage the Wellbrook has is that you can turn it but you can always build two passive loops at right angles to each other and switch between them. This is good for all except nulling of course. I think the Wellbrook is worth the money but if you don't want to spend that much or if you like to make your own passive loop its easy. The noisiest locations will probably still do better with the Wellbrook though. I don't think you can beat a well designed small amplified loop for a poor receiving location. -- Telamon Ventura, California |
#3
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What a beautifully and clearly written explanation!
"Telamon," if you don't already write reviews (or have never even thought of doing so), you certainly should! Best, Joe |
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