The spider-web col is just as well as a ferrite-antenna suited for a tuned LC-tank circuit. So you need a variable capacitor or varactor in parallel to them at the input of a radio-module. Modern digitl radio-modules (like our Si4735 module) in fact do tune a magnetic antenna autimatically with an internal varactor.
Sir I just restored a G.E tube radios a 60 era the ferrite antenna that came with it was shattered into several pieces,I bought a replacement ferrite bar blank and some 22 gauge magnetic wire ,and some.heat proof tape to tape the start of the wrapping to hold stuff in place while I will be wrapping the rest of the ferrite bar ,any advice you can offer me I would be greatful,anyone ? I haven't wrapped it yet tomorrow ,I will this antenna will be a replacement for the AM antenna that was broken ,I hoping to make a copy ,then dip it into hot wax to keep everything in place .I wonder if anyone else has done this
It´s just a matter of finding the right number of turns to get the correct inductance with an unknown ferrite rod. There are so many variables (ferrite material, diameter, length, shape, position of the coil on the rod) that you can only it determine it experimentally. Try to find litz-wire with approximately the same number of wires and diameter and just start with "too many" turns because later it´s easier to shorten a winding than to "lengthen" it :-) You will get a too high inductance first and then have lower frequencies on your frequency dial. Just try to find a known AM-station and then change the number of turns until the frequency dial is correct again. Fine-tuning of the inductance is done by shifting the winding on the ferrite rod.
I'm looking to run 10 and 11 meters I have a Stryker 955 radio which is at 10 and 11 meter radio and I also have a Cobra 2000 my problem is I live in an apartment I need something that will work for me inside the apartment or on the balcony I can't run any wire past my balcony can you help me out also I am disabled and have limited use of my arms and hands so it has to be something easy
Use a (single-turn) loop made of thick copper-tubing (20...30 mm diameter) The best book about this topic is "Magnetic Loop Antenna" by Burger && Dvorsky: ISBN: 978-80-260-9952-9 www.box73.de/product_info.php?products_id=3629 Strangely it´s not available from Amazon.com (might be self-published?)
Love your videos Roger! 👍
I realize the possibility of an english version of your web store is remote but I would like that
thanks
so I just need to connect the spider-web antenna to the module and connect the module to the amp to listen? thanks.
The spider-web col is just as well as a ferrite-antenna suited for a tuned LC-tank circuit. So you need a variable capacitor or varactor in parallel to them at the input of a radio-module. Modern digitl radio-modules (like our Si4735 module) in fact do tune a magnetic antenna autimatically with an internal varactor.
Sir I just restored a G.E tube radios a 60 era the ferrite antenna that came with it was shattered into several pieces,I bought a replacement ferrite bar blank and some 22 gauge magnetic wire ,and some.heat proof tape to tape the start of the wrapping to hold stuff in place while I will be wrapping the rest of the ferrite bar ,any advice you can offer me I would be greatful,anyone ? I haven't wrapped it yet tomorrow ,I will this antenna will be a replacement for the AM antenna that was broken ,I hoping to make a copy ,then dip it into hot wax to keep everything in place .I wonder if anyone else has done this
It´s just a matter of finding the right number of turns to get the correct inductance with an unknown ferrite rod. There are so many variables (ferrite material, diameter, length, shape, position of the coil on the rod) that you can only it determine it experimentally. Try to find litz-wire with approximately the same number of wires and diameter and just start with "too many" turns because later it´s easier to shorten a winding than to "lengthen" it :-)
You will get a too high inductance first and then have lower frequencies on your frequency dial. Just try to find a known AM-station and then change the number of turns until the frequency dial is correct again. Fine-tuning of the inductance is done by shifting the winding on the ferrite rod.
@@KainkaLabs thank for your help
I'm looking to run 10 and 11 meters I have a Stryker 955 radio which is at 10 and 11 meter radio and I also have a Cobra 2000 my problem is I live in an apartment I need something that will work for me inside the apartment or on the balcony I can't run any wire past my balcony can you help me out also I am disabled and have limited use of my arms and hands so it has to be something easy
Use a (single-turn) loop made of thick copper-tubing (20...30 mm diameter)
The best book about this topic is "Magnetic Loop Antenna" by Burger && Dvorsky:
ISBN: 978-80-260-9952-9
www.box73.de/product_info.php?products_id=3629
Strangely it´s not available from Amazon.com (might be self-published?)