Questions tagged [ferrite]
The ferrite tag has no usage guidance.
39 questions
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Will 2 ferrite beads taped side by side perform the same as a single-piece binocular core?
I intend to make a beverage antenna and have quite a few spare ferrite beads of various mixes. If you look up binocular core ferrite on amazon you will see they are a single chunk piece of ferrite ...
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Why do 9:1 ununs use type 2 material for the core?
I do not understand how a 9:1 unun wound on a T200-2 works. I understand the transformer voltage and current ratios. I have wound several toroid chokes and 49:1 ununs and know how they work. What is ...
user23405
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trying to get a passive AM bar antenna to work
I pulled a nice big external AM ferrite bar antenna off a working stereo. 5.5" long.
it has 4 wires coming off of it. red must be the main wire, because checking that with an LCR meter connected ...
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What are these extra wires coming out of my ferrite rod antenna
From my understanding a ferrite rod antenna is simply a length of wire wrapped around a ferrite rod. A wire will sticks out of each side of the rod, one is ground and one is the main receiver.
I ...
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60kHz WWVB receiver help
I have built a large ferrite loopstick antenna based off this video. I live in Washington state and am trying to receive and decode WWVB. I can get my antenna to resonate at 60kHz with ~700 pF of ...
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How to achieve highest Q-factor in inductors for 6-160m amateur bands?
When building filters for ham bands (direct sampling SDR frontend) - it is common to build filters using 2,6,10,12 material toroids. Are there any recent developments that offer lower losses / higher-...
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Ferrites losses calculation
I am new on RF design. I would like to know more about ferrites. I am looking for information about how to calculate ferrite losses and saturation points for a given application. I also would like to ...
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Using PVC coated solid-core wire for a small number of turns on toroid
I'm researching making my own 49:1 unun using an appropriate mix ferrite toroid and some reasonable gauge solid-core wire. (This is for an experimental HF end-fed antenna, though this detail probably ...
user21417
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Core mix preferences for a balun (or unun) vs a choke
Was watching a YouTube video a little while ago and an engineer from Palomar engineers mentioned that using Mix #31 cores for balun construction wasn't ideal.
He went on to mention that Mix 31 (or 43 ...
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Ferrite choice for fan dipole
I am intending to build a two element fan dipole for 80 and 20m. How should I go about choosing a ferrite toroid and number of windings for the balun, to operate effectively over such a range of ...
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Can ferrite rod antenna be made out of the choke?
I'm reading the instructions on preparing the ferrite rod antenna. If I understand it correctly it is matter of building an LC circuit.
My question is: Can the ferrite rod antenna be built using a ...
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How to meassure a ferrite using a VNA?
I want to measure a ferrite toroid using a VNA. I would like to classify it for a whole range of frequencies but if it's too complicated I'm OK to just pick one frequency.
I have 3 questions actually:
...
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Is this true about ferrite loop antennas?
There is an article on wikipedia about loop antennas.
It shows like an AM radio's antenna with the ferrite rod and says this:
This greater conductance channels thousands of times more magnetic power ...
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Why are loopstick ferrite antennas commonly wound with Litz wire?
What is the advantage of using Litz wire to wind ferrite (loopstick) antennas? How much of an advantage in what characteristic does this type of wire provide? (over generic single strand enameled or ...
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How does a loopstick antenna actually receive signal?
Around 1970, I acquired a little transistor radio (powered by 4xAA cells, 6V) that had no external antenna. Inside the back panel (which opened to allow replacing the battery cells) one could see the ...
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Can a slinky serve as a ferrite core and if so, is there a prefered configuration? [closed]
Ferrite cores ain't cheap when you start talking about the 3 inch ID ones. I can see em for like 40 and 50 bucks....
I don't see why I can't just ground a slinky or something.
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How do you calculate the number of turns for a common mode choke?
I want to build a common mode choke for my end-fed wire antenna, using turns of coax through an FT140 or FT240 ferrite. I can find various finished products for sale, but I want to make my own. I ...
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How to effectively test and interpret the "working range" of a ferrite core with a signal analyzer?
I have a couple of ferrite beads that are advertised as effective for suppressing conductive noise around 150kHz. I'm trying to monitor their actual performance with noise filtering.
In my set up I ...
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Importance of Ferrite Size in Coax Choke Balun
The question is quite simple: When making a coax choke balun, does the size of the ferrite matter, and if so, why?
I have seen design notes that say to use a single FT240-43 toroid for powers up to ...
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How does this 3 dB splitter/combiner work?
I'm having difficulties to understand how does this circuit work:
Apparently T1 is a regular 50 Ohm to 22.2 Ohm autotransformer. Turns ratio 2:3 gives a 0.66**2 impedance converation. Since the load ...
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9:1 unun material and power loss
I need to build another 9:1 unun and I start searching for my toroids... (I have build 2-3 something like 4 years ago)...
In parallel I checked on Google about the correct toroid etc so I found 2-3 ...
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Commercial Loopstick Antenna Manufacturers?
I am an electrical engineer working on a product that needs a loopstick antenna.
I had thought that AM radios were so commoditized that I'd be able to find an off-the-shelf vendor. However the closest ...
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What causes differences in properties of ferrite cores from same material?
Why are the shapes of the impedance curves different for cores made of the same ferrite material?
The impedance (Z) of an inductor wound on a ferrimagnetic core is:
$$Z=j\omega L_s + R_s = j\omega ...
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UHF cubical quad VNA analysis interpretation (part2)
This is the follow up to:
UHF cubical quad VNA analysis interpretation
This is a S21 and S31 analysis of an oversized 385 Mhz 50 Ohm to 90 Ohm balun between 100 Mhz and 600 Mhz
I tested phase ...
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How do I evaluate and use a toroidial core for my HF double-balanced mixer?
Last year, I planned to make a double-balanced mixer covering the entire 3-30 MHz band as an upconverter for my RTL-SDR receiver, mainly for learning RF circuits and ham radio. Naturally, it requires ...
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How to measuring ferrite core efficiency vs frequency
There is an unknown ferrite toroid. I would like to figure out whether it can be used in an audio transformer, or maybe in a 1:4 transformer on given HF frequency.
The experiment I came up with is ...
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Can ferrite beads lower coax cable velocity factor?
For VHF and UHF, it seems reasonable to slip ferrite beads over a coaxial cable to act as a transmission line common mode choke. It also seems reasonable to use beads with the smallest diameter ...
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Can I make ferrite paint? Will it shield my antenna from my roof?
I have a 3 element vertical Yagi mounted on a rotator, and in one direction the roof of the house gets pretty close and messes up the SWR a bit.
If i mash up a few type 43 material ferrite cores and ...
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How to make a ferrite bar antenna for RTL-SDR?
I bought a RTL-SDR (blue one with little MCX antenna). I modified its Q branch, and can receive short wave radio with Degen 31MS antenna now.
For MW, Degen 31MS antenna has a ferrite bar antenna ...
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Is this the Correct Ferrite Core to Reduce RFI as a Common Mode Choke?
I have a Flex 3000 connected via RG-11 coax to a inverted V fan dipole tuned for 40m and 20m on my roof. I have an "ugly" balun up on the mast by the antenna. I further have the feed-line going into a ...
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What is the maximum number of turns in a ferrite core used as a common mode choke?
Is there a way to estimate the maximum number of turns which can be used with a ferrite core used as a common mode choke?
It is known that the impedance of such a choke is proportional to the square ...
- 1,062
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Need a ferrite suppression material for choking 15 kHz to 60 kHz
Electric fence RFI is ruining reception on our VLF lightning receivers, and we need a material to place around neighbors' fence wires to suppress the noise being radiated. Preferably, a split bead, ...
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What core material do I need to construct a 1:1 unun for 6M?
I want to build a 1:1 unun for a 6M dipole. Power level 100W. What core material should I use?
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Ferrite rod or core permeability determination
Is there a simple empiric way of determining the permeability (mhu) of a ferrite object (be it a ring, rod or any form)?
I've been thinking this for a rod: if I wind coils with different number of ...
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Are some ferrites porous enough they should be protected outside?
I recently bought a couple of 61-mix toroids, and as usual I wrote the mix number on them before they become mystery parts. However, the ink soaked right into the ferrite.
I've left ferrites hanging ...
- 52.4k
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Do a toroid's specs matter much in an antenna matching transformer?
I'm getting started with my first (very basic) HF rig and for convenience and the experience I'd like to try an End Fed Half Wave antenna. Typical designs for a "matchbox" in this case include ...
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Ferrite Rod Price Differences
We are trying to make a VLF geophysics device for our graduate project and we need two ferrite rod antennas (desired length is 6").
Searching on the internet, we have found two ferrite rod suppliers.
...
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How does one read a ferrite datasheet?
Datasheets for ferrite materials are usually filled with incomprehensible graphs with greek letters. For example, Fair-Rite's 73 material:
What's a $\mu'_s$ and a $\mu''_s$? What do these numbers ...
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What's an appropriate core material for a loopstick antenna?
A loopstick antenna, if you don't know, is a coil of many turns around a high permeability core. They are frequently encountered in AM receivers and look like this:
This particular example is ...
- 52.4k