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#1
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ELFA,
"BA" gave you some good advise. Before you start the windings. * Find a 6.5" to 8" Ferrite Rod Antenna (FRA). * 10 Feet of Wire (Magnet or Litz) * Cut a 2" X 2" piece of Typing/Copier Paper 20/24LB) * Wrap the Copier Paper around the FRA (About Two(2) Layers & Tape the Joint) - - - The Copier Paper will 'form' a "Tube" that can be moved on the FRA. * Wrap 50-80 Wire Windings over the Copier Paper Tube to form a "Moveable Coil Assembly (The Coil). * Set the Windings at the very tip of one of the Ends of the FRA. * Connect the Variable "Tuning" 360-400pf Capacitor (VTC) to the Leads from the Windings. # Place the FRA and VTC next to a Radio: Ideally you would use a Radio with a Digital Frequncy Display and a "S" Meter. * Starting-Mid-Point: "Tune" the Radio to a medium strength AM/MW Radio Station at the Middle of the AM/MW Band 800-1000 kHz. - Set the VTC to its Middle/Center Position. - - Very Slowly 'move' The Coil from the Tip of the FRA towards the center of the FRA. - - - Try to identify by Ear or Eye an change in the Quality and Strength of Reception. - - - - Mark-Measure-Record this 'position'. Note: If you 'find' a "Sweet Spot" on this first try: You have Luck-Out ! * Top-End-Point: "Tune" the Radio to a medium strength AM/MW Radio Station at the High-End of the AM/MW Band 1500-1700 kHz. - Set the VTC to its Fully "OPEN" Position. - - Very Slowly 'move' The Coil from the 'prior' (Starting-Mid-Point) position towards the Tip of the FRA and then towards the center of the FRA. - - - Try to identify by Ear or Eye an change in the Quality and Strength of Reception. - - - - Mark-Measure-Record this 'position'. * Bottom-End-Point: "Tune" the Radio to a medium strength AM/MW Radio Station at the Low-End of the AM/MW Band 550-700 kHz. - Set the VTC to its Fully "CLOSED" Position. - - Very Slowly 'move' The Coil from the 'prior' (Top-End-Point) position towards the Tip of the FRA and then towards the center of the FRA. - - - Try to identify by Ear or Eye an change in the Quality and Strength of Reception. - - - - Mark-Measure-Record this 'position'. NOTE: Ideally these three points are within a 1/8" of each other and you would set The Coil in the the middle of the three. However the reality is that this will not be the case and you will have to REMOVE/ADD a few Windings and try the above process again. TIP: If you can "Tune" the Low-End and/or Middle of the AM/MW Band then REMOVE a few Windings. Or, if you can "Tune" the High-End and/or Middle of the AM/MW Band then ADD a few Windings. iane ~ RHF .. .. = = = "Brenda Ann" = = = wrote in message ... "elfa" wrote in message ... I appreciate your offer of instructions re the ferrite bar antenna but I think I'll just skip it for now. This was the wrong group for this kind of request. It should have been in an electronics group. elfa The number of turns necessary for a loopstick antenna depends on several factors. 1) the frequency range required 2) the permeability of the ferrite core 3) the spacing of the turns For experimentation purposes, you might start with about 80 turns of AWG 30 enameled or cloth covered wire, contiguously spaced, near one end of the core. With this, use a ~360 pF variable capacitor. If you have a grid dip meter, you can easily find where this is resonant. If you don't, then you have to poke about on the AM dial of a cheap radio, and see where you can tune it. |
#2
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RHF,
That post just made it into my "save" file. Thanks for the excellent instruction. -- Stinger "RHF" wrote in message om... ELFA, "BA" gave you some good advise. Before you start the windings. * Find a 6.5" to 8" Ferrite Rod Antenna (FRA). * 10 Feet of Wire (Magnet or Litz) * Cut a 2" X 2" piece of Typing/Copier Paper 20/24LB) * Wrap the Copier Paper around the FRA (About Two(2) Layers & Tape the Joint) - - - The Copier Paper will 'form' a "Tube" that can be moved on the FRA. * Wrap 50-80 Wire Windings over the Copier Paper Tube to form a "Moveable Coil Assembly (The Coil). * Set the Windings at the very tip of one of the Ends of the FRA. * Connect the Variable "Tuning" 360-400pf Capacitor (VTC) to the Leads from the Windings. # Place the FRA and VTC next to a Radio: Ideally you would use a Radio with a Digital Frequncy Display and a "S" Meter. * Starting-Mid-Point: "Tune" the Radio to a medium strength AM/MW Radio Station at the Middle of the AM/MW Band 800-1000 kHz. - Set the VTC to its Middle/Center Position. - - Very Slowly 'move' The Coil from the Tip of the FRA towards the center of the FRA. - - - Try to identify by Ear or Eye an change in the Quality and Strength of Reception. - - - - Mark-Measure-Record this 'position'. Note: If you 'find' a "Sweet Spot" on this first try: You have Luck-Out ! * Top-End-Point: "Tune" the Radio to a medium strength AM/MW Radio Station at the High-End of the AM/MW Band 1500-1700 kHz. - Set the VTC to its Fully "OPEN" Position. - - Very Slowly 'move' The Coil from the 'prior' (Starting-Mid-Point) position towards the Tip of the FRA and then towards the center of the FRA. - - - Try to identify by Ear or Eye an change in the Quality and Strength of Reception. - - - - Mark-Measure-Record this 'position'. * Bottom-End-Point: "Tune" the Radio to a medium strength AM/MW Radio Station at the Low-End of the AM/MW Band 550-700 kHz. - Set the VTC to its Fully "CLOSED" Position. - - Very Slowly 'move' The Coil from the 'prior' (Top-End-Point) position towards the Tip of the FRA and then towards the center of the FRA. - - - Try to identify by Ear or Eye an change in the Quality and Strength of Reception. - - - - Mark-Measure-Record this 'position'. NOTE: Ideally these three points are within a 1/8" of each other and you would set The Coil in the the middle of the three. However the reality is that this will not be the case and you will have to REMOVE/ADD a few Windings and try the above process again. TIP: If you can "Tune" the Low-End and/or Middle of the AM/MW Band then REMOVE a few Windings. Or, if you can "Tune" the High-End and/or Middle of the AM/MW Band then ADD a few Windings. iane ~ RHF . . = = = "Brenda Ann" = = = wrote in message ... "elfa" wrote in message ... I appreciate your offer of instructions re the ferrite bar antenna but I think I'll just skip it for now. This was the wrong group for this kind of request. It should have been in an electronics group. elfa The number of turns necessary for a loopstick antenna depends on several factors. 1) the frequency range required 2) the permeability of the ferrite core 3) the spacing of the turns For experimentation purposes, you might start with about 80 turns of AWG 30 enameled or cloth covered wire, contiguously spaced, near one end of the core. With this, use a ~360 pF variable capacitor. If you have a grid dip meter, you can easily find where this is resonant. If you don't, then you have to poke about on the AM dial of a cheap radio, and see where you can tune it. |
#3
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Stinger,
Thank You, ELFA did not indicate that he had any test equipment Grid Dip Meter etc. So this was the simplest method by just using a basic AM/MW Radio. A Copy of this simple method is posted to: * " Ferrite Rod Antenna for Experimenters" eGroup on YAHOO! http://groups.yahoo.com/group/FerriteRodAntenna/ * "SWL Antennas and AM & FM Antennas" eGroup on YAHOO! http://groups.yahoo.com/group/SWL-AM-FM-Antenna/ ~ RHF .. .. = = = "Stinger" = = = wrote in message ... RHF, That post just made it into my "save" file. Thanks for the excellent instruction. -- Stinger "RHF" wrote in message om... ELFA, "BA" gave you some good advise. Before you start the windings. * Find a 6.5" to 8" Ferrite Rod Antenna (FRA). * 10 Feet of Wire (Magnet or Litz) * Cut a 2" X 2" piece of Typing/Copier Paper 20/24LB) * Wrap the Copier Paper around the FRA (About Two(2) Layers & Tape the Joint) - - - The Copier Paper will 'form' a "Tube" that can be moved on the FRA. * Wrap 50-80 Wire Windings over the Copier Paper Tube to form a "Moveable Coil Assembly (The Coil). * Set the Windings at the very tip of one of the Ends of the FRA. * Connect the Variable "Tuning" 360-400pf Capacitor (VTC) to the Leads from the Windings. # Place the FRA and VTC next to a Radio: Ideally you would use a Radio with a Digital Frequncy Display and a "S" Meter. * Starting-Mid-Point: "Tune" the Radio to a medium strength AM/MW Radio Station at the Middle of the AM/MW Band 800-1000 kHz. - Set the VTC to its Middle/Center Position. - - Very Slowly 'move' The Coil from the Tip of the FRA towards the center of the FRA. - - - Try to identify by Ear or Eye an change in the Quality and Strength of Reception. - - - - Mark-Measure-Record this 'position'. Note: If you 'find' a "Sweet Spot" on this first try: You have Luck-Out ! * Top-End-Point: "Tune" the Radio to a medium strength AM/MW Radio Station at the High-End of the AM/MW Band 1500-1700 kHz. - Set the VTC to its Fully "OPEN" Position. - - Very Slowly 'move' The Coil from the 'prior' (Starting-Mid-Point) position towards the Tip of the FRA and then towards the center of the FRA. - - - Try to identify by Ear or Eye an change in the Quality and Strength of Reception. - - - - Mark-Measure-Record this 'position'. * Bottom-End-Point: "Tune" the Radio to a medium strength AM/MW Radio Station at the Low-End of the AM/MW Band 550-700 kHz. - Set the VTC to its Fully "CLOSED" Position. - - Very Slowly 'move' The Coil from the 'prior' (Top-End-Point) position towards the Tip of the FRA and then towards the center of the FRA. - - - Try to identify by Ear or Eye an change in the Quality and Strength of Reception. - - - - Mark-Measure-Record this 'position'. NOTE: Ideally these three points are within a 1/8" of each other and you would set The Coil in the the middle of the three. However the reality is that this will not be the case and you will have to REMOVE/ADD a few Windings and try the above process again. TIP: If you can "Tune" the Low-End and/or Middle of the AM/MW Band then REMOVE a few Windings. Or, if you can "Tune" the High-End and/or Middle of the AM/MW Band then ADD a few Windings. iane ~ RHF . . = = = "Brenda Ann" = = = wrote in message ... "elfa" wrote in message ... I appreciate your offer of instructions re the ferrite bar antenna but I think I'll just skip it for now. This was the wrong group for this kind of request. It should have been in an electronics group. elfa The number of turns necessary for a loopstick antenna depends on several factors. 1) the frequency range required 2) the permeability of the ferrite core 3) the spacing of the turns For experimentation purposes, you might start with about 80 turns of AWG 30 enameled or cloth covered wire, contiguously spaced, near one end of the core. With this, use a ~360 pF variable capacitor. If you have a grid dip meter, you can easily find where this is resonant. If you don't, then you have to poke about on the AM dial of a cheap radio, and see where you can tune it. |
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