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On Apr 18, 5:59 pm, "SWL-2010" wrote:
I live in an apartment with no balcony, so reception can be a challenge. A few years ago, I used a 32" telescoping whip I had in my spare parts box, and wrapped the entire length in a very tight coil of small guage copper wire. I left about 10" on the end, and screwed a large alligator clip on it. (I does not look like much, but in the window, it's almost invisible). Then I take it, and I place in in the window frame between the screen and the glass, so even if it's cold, I can still close the window almost all the way. I use 25 feet of small guage speaker wire with alligator clips on each end for my end fed feedline. I can then clip it to anything. It works well with portables of benchtop receivers. I can clip it to the antenna on top of my old Drake SSR and make it come alive. I can clip it to the back of my Kenwood R-300 and get the same result. On portables, I generally do not get overload. If I do, I just hook it to my MFJ-959B, and then I can play around with, or antennuate the signals. It was fun, it was cheap, and it works great. Mini-BroomStick Shortwave Listening (SWL) Antenna - In-the-Window http://groups.yahoo.com/group/Shortw.../message/12978 SWL-2010, Glad that you are enjoying your Home-Brewed In-the-Window Shortwave Listening (SWL) Antenna. But in general if you simply wrap Wire around a Metal Object and then use that Coiled Wire as an Antenna : You have simply increased the Diameter of the Metal Object by placing the Wire around it -and- the Electro-Mechanical properties of the Metal Object make the Wire Coil a slightly larger version of the original Metal Object. - - - Example : A 1/4" by 36" Brass Tube becomes a 3/8" by 36" Copper Wire Tube. Most of the time when a "Form" {Foundation} is used to Wrap Wire-On it is non-metalic. So often a Wood Dowel or a Plastic Tube. -Tip- White PVC Pipe works OK as a Form. 1 - Measure the Diagonal of a Window and Cut the Form to that Length. 2 - Drill a Hole through the Form close to both Ends. 3 - Use Stranded Hook-Up Wire for the Antenna Element 4 - Place one-end of the Wire in one of the Holes and tie a Knot in the Short piece of Wire coming out leaving 3"-6" inches to work with. 5 - Use a 12-18" piece of Thicker # 14 AWG Solid Copper Wire and Wrap it around the Form with the Antenna Wire about 3-4 Turns. The Thicker Solid Copper Wire becomes your Wire Spacing {Gap} Form to Wrap the Coil around the Form. Snake it {slowly and carefully} around the Form as you Wind your Antenna Wire Coil around the Length of the Form. 6 - When you get to the other-end of the cut the Wire so that you have about 3-6" to work with; and place the end of the Wire in the Hole at that end; and Tie a Knot in the Short piece of Wire coming out; and trim off the excess Wire. FWIW - On a 3/4" by 36" piece of PVC Pipe you will have about 5-6 Turns of Wire per Liner-Inch of Pipe. That would Add-Up-To about 180-216 Turns along the Length of the Pipe. The Length of Wire in One-Turn would be about 2.4" : So the Length of the Antenna Wire Element would be about 432-518" or about 36-43 Feet long. USE TIPS : * Generally with most In-the-Window Antennas having the Radio next to the Window {Very Close} is the better placement of the Antenna and Radio. * Clip a 'short' Lead-in-Wire from the Antenna to the Collapsed Whip Antenna of the Radio or the HI-Z Terminal of the Receiver. Sometimes you may find that using a Banana Plug pushed into the Center Pin of the LO-Z SO239 Plug works better. * Grounding the Radio may or may-not help. * -IF- You have an old 6.5" to 8" AM/MW Radio Ferrite Rod Core laying around : You can try sliding it In-and-Out of the Pipe to see what effect it has on AM/MW Reception. [IMHO] The-Better-Way * For Shortwave Receivers - Take a 3-8 Feet Piece of Coax Cable with a PL-359 Plug on One-End and only an Alligator Clip to the Center Conductor on the other-end can work well as a feed-in-line to reduce some of the "In-Side-Noise" -and- Again try this with the Receiver Grounded and Ungrounded. * For 'portable' AM/FM Shortwave Radios - Take a 3-8 Feet Piece of "Audio" {1/8"} Coax Cable with a 1/8" Mono Plug on One-End and only an Alligator Clip to the Center Conductor on the other-end can work well as a feed-in-line to reduce some of the "In-Side-Noise" -and- Again try this with the Radio Grounded and Ungrounded. Basically what you end up building is a shortened version of the so-called "BroomStick" {BroomStik} Antenna placed In-the-Window. READ - About - The Broomstick Antenna [Was: (repost) BroomStick Antenna Success ? http://www.google.com/group/rec.radi...95c243a57e7d1c * Short STACKED Vertical {Tri-Band} BroomStick Antenna http://www.google.com/group/rec.radi...c7e2e6a6bb395c * Arnie Coro 'BroomStick' Antenna - Getting Any Results? http://www.google.com/group/rec.radi...7afe4778718066 * One-More-Time - Arnie Coros' BroomStick Antenna - - - The "BS's" Secret's Revealed . . . http://www.google.com/group/rec.radi...abeec559035337 How to Ride the Radio Waves on a BroomStick ! - iane ~ RHF {pomkia} .. | | | / \ ........!....... |
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