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Sorry, I should have given more information.
I've used a B&W ACS-1.8-30 inverted vee in the past and that is way way too big. So I need something smaller than that. I like the size of the Wellbrook ALA 300. I think I'll go with that. John |
In article , Mark S. Holden wrote:
wrote: Hi, I need broadband (2MHz - 30MHz) receive-only capability. I will be connecting the antenna to a system that can stare at 10 MHz of RF spectrum simultaneously. I have very limited space and almost no antenna experience. .... Active antennas amplify everything they pick up including your neighbors lamp ^^^^^^^^^ dimmer, your crt computer monitor and possibly any VCR's you might have. If ^^^ ^^^^^^^^ you're gonna get one, I suggest installing it away from the house. Given the description of the receiver, I suspect that the OP wants to do some Van Eck monitoring. (Remote viewing of computer displays). With current computer displays better results are probably obtained in the VHF frequency range. Also, monitors are much better shielded now than they were when Van Eck wrote his paper, before the FCC cracked down on computer generated interference. The only other things I think that bandwidth in that frequency range would be good for would be hacking BPL, or making a very high resolution lightning strike detector. Mark Zenier Washington State resident |
Nope. Be able to display a waterfall graph of a 10 MHz wide portion of
HF so as to identify active transmissions/frequencies. John |
In article .com,
wrote: Nope. Be able to display a waterfall graph of a 10 MHz wide portion of HF so as to identify active transmissions/frequencies. Cool. My guess, to match your constraints, would be an amplified untuned loop. (Probably the Wellbrook if you can afford it). But I wonder, if there's no narrowband selectivity inside the box, just how sensitive you can be with that bandwidth. (The Laws of Physics and all that). Mark Zenier Washington State resident |
I believe the ability to null goes down as the loop becomes less
"small." I suspect if you made a smaller loop for your wellbrook, it would become directional again, but the gain would be lower due to smaller aperture. |
If your goal is to identify the signals, I think the vertical with amp
(i.e. Might FIne Junk 1024 or even home-brew version) will do the job. I suspect (but have no first hand knowledge) that noise sources will not be very coherent, so they won't spike a spectrum analyser like a real RF signal. If you wanted to listen to the signal you identified, then I'd go for the Wellbrook. |
Hello.
It appears that you are going to buy a Wellbrook ALA 330S Active Loop Antenna (there is no such model as ALA 300). Note that while this antenna will afford you superb reception (I recommend that you read Jay Allen's review at this URL: http://www.radiointel.com/review-wellbrook.htm), just buying it is not all you will have to do. There are other items you must purchase locally AND the antenna MUST be properly mounted and installed. (A fence-post or deck railing is a good location. An attic is an even better one. Even though the instructions mention the optimum outdoor mounting location, it is definitely not critical. I prefer attic-mounting as the antenna performs in a superlative fashion in that location and it (and its associated equipment) - no small invenstment! - is protected from the weather). If you are indeed serious, please read the following carefully. You will need to buy a suitable length of RG-58C/U (in the United States often labeled RG-58U - this is the same thing) coaxial cable (no other kind will do!) and two (2) BNC connectors. This can be purchased at your local Radio Shack. Should you wish to take advantage of the antenna's directional capabilities (recommended), you will need to purchase a Radio Shack antenna rotator (about $75.00) and the special cable for that rotator (about $15.00). You will also need a suitable length of PVC (preferably) pipe which attaches the antenna to the rotator (about $2.00 at your local hardware store). All of this MUST be hooked up in STRICT accordance with the instructions packed with the antenna. IF --- you follow the instructions EXACTLY, the installation process is quite easy and shouldn't take more than an hour or two. IF --- you feel that you are incapable of doing the installation yourself, I strongly recommend that you hire a competent electrician to install the antenna for you. MAKE SURE that he READS the instructions CAREFULLY before attempting the installation. (Installation charge will probably be between $200-$300.) You will want to contact THE SHORTWAVE SHOP in the UK if you wish to make the purchase with a credit card. You can buy directly from Andy Ikin at the factory, but he accepts checks only. (Also THE SHORTWAVE SHOP sometimes charges less.) I believe the current price in dollars, including shipping, is around $350.00. Note too that there may be a delay in shipment; Andy has been quite backed-up of late due to an overwhelming number of orders (the "word" has gotten around about this antenna!), though I think he is catching up to some extent. IF --- you are willing to go to the lengths necessary to acquire this antenna, you will be rewarded with probably the finest antenna ever designed for the shortwave listener. (The purchase "hurdles" are deliberate: Wellbrook is a "one-man" operation and Andy can make only so-many antennas!) You want to hear very weak signals? This is your antenna! I own one. In all my forty-plus years of shortwave listening, I personally have never experienced ANY antenna even nearly as good as the Wellbrook ALA 330S. Best of luck, Joe |
Joe Analssandrini wrote: Hello. It appears that you are going to buy a Wellbrook ALA 330S Active Loop Antenna (there is no such model as ALA 300). Note that while this antenna will afford you superb reception (I recommend that you read Jay Allen's review at this URL: http://www.radiointel.com/review-wellbrook.htm), just buying it is not all you will have to do. There are other items you must purchase locally AND the antenna MUST be properly mounted and installed. (A fence-post or deck railing is a good location. An attic is an even better one. Even though the instructions mention the optimum outdoor mounting location, it is definitely not critical. I prefer attic-mounting as the antenna performs in a superlative fashion in that location and it (and its associated equipment) - no small invenstment! - is protected from the weather). If you are indeed serious, please read the following carefully. You will need to buy a suitable length of RG-58C/U (in the United States often labeled RG-58U - this is the same thing) coaxial cable (no other kind will do!) and two (2) BNC connectors. This can be purchased at your local Radio Shack. Should you wish to take advantage of the antenna's directional capabilities (recommended), you will need to purchase a Radio Shack antenna rotator (about $75.00) and the special cable for that rotator (about $15.00). You will also need a suitable length of PVC (preferably) pipe which attaches the antenna to the rotator (about $2.00 at your local hardware store). All of this MUST be hooked up in STRICT accordance with the instructions packed with the antenna. IF --- you follow the instructions EXACTLY, the installation process is quite easy and shouldn't take more than an hour or two. IF --- you feel that you are incapable of doing the installation yourself, I strongly recommend that you hire a competent electrician to install the antenna for you. MAKE SURE that he READS the instructions CAREFULLY before attempting the installation. (Installation charge will probably be between $200-$300.) You will want to contact THE SHORTWAVE SHOP in the UK if you wish to make the purchase with a credit card. You can buy directly from Andy Ikin at the factory, but he accepts checks only. (Also THE SHORTWAVE SHOP sometimes charges less.) I believe the current price in dollars, including shipping, is around $350.00. Note too that there may be a delay in shipment; Andy has been quite backed-up of late due to an overwhelming number of orders (the "word" has gotten around about this antenna!), though I think he is catching up to some extent. IF --- you are willing to go to the lengths necessary to acquire this antenna, you will be rewarded with probably the finest antenna ever designed for the shortwave listener. (The purchase "hurdles" are deliberate: Wellbrook is a "one-man" operation and Andy can make only so-many antennas!) You want to hear very weak signals? This is your antenna! I own one. In all my forty-plus years of shortwave listening, I personally have never experienced ANY antenna even nearly as good as the Wellbrook ALA 330S. You've never strung up any really long wires? dxAce Michigan USA http://www.iserv.net/~n8kdv/dxpage.htm |
In article ,
"Mark S. Holden" wrote: Dave Holford wrote: snip Loops are directional, as are dipoles etc.snip Wellbrook suggests a rotator for LW and MW on the 1530, but they don't seem to call for one for HF. http://www.wellbrook.uk.com/ALA1530.html The loop will have a more directional pattern the lower in frequency you go. -- Telamon Ventura, California |
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